[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "6"]
[White "Herrera Jimenez, Mateo"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B01"]
[WhiteElo "1943"]
[BlackElo "2087"]
[PlyCount "64"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 e5 5. dxe5 Bb4 6. Bd2 Nc6 7. Nf3 Bg4 8. a3 Nd4 9. Be2 Bxf3 10. Bxf3 Qxe5+ 11. Be2 Bxc3 12. Bxc3 0-0-0 13. Qd3 Nf6 14. Bxd4 Rxd4 15. Qe3 Re4 16. Qh3+ Kb8 17. 0-0-0 Rxe2 18. Rd3 Re1+ 19. Rxe1 Qxe1+ 20. Rd1 Qxf2 21. Qd3 a6 22. Kb1 Qxg2 23. Re1 Qxh2 24. Re7 Qh1+ 25. Ka2 Qd5+ 26. Qxd5 Nxd5 27. Rxf7 h5 28. Rxg7 h4 29. Rg1 h3 30. c4 h2 31. Rh1 Ne3 32. b3 Ng4 0-1

[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "4"]
[White "Meza Galvan, Victor Andres"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B01"]
[WhiteElo "1707"]
[BlackElo "2087"]
[PlyCount "66"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. e4 d5 2. exd5 Qxd5 3. d4 c6 4. Nf3 Bg4 5. Be2 e6 6. Nc3 Bb4 7. a3 Bxc3+ 8. bxc3 Bxf3 9. Bxf3 Qc4 10. Bd2 Nf6 11. Qe2 Qa4 12. Be4 Nbd7 13. 0-0 Nxe4 14. Qxe4 Nf6 15. Qd3 b5 16. Rfe1 Nd5 17. f4 0-0 18. f5 exf5 19. Qxf5 Qc4 20. Re4 Nxc3 21. Rg4 Ne2+ 22. Kh1 Qe6 23. Qg5 g6 24. Rf1 f5 25. Rh4 Rae8 26. Qh6 Rf7 27. Bg5 Qc4 28. Bf6 Ng3+ 29. hxg3 Qxf1+ 30. Kh2 Re1 31. g4 f4 32. Qg7+ Rxg7 33. Rxh7 Qh1# 0-1

[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "2"]
[White "Quesada Perez, Luis Ernesto"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B06"]
[WhiteElo "2567"]
[BlackElo "2087"]
[PlyCount "47"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. e4 d6 2. d4 g6 3. Nc3 Bg7 4. h4 h5 5. Be3 Nf6 6. f3 Nbd7 7. Qd2 c5 8. Nge2 a6 9. dxc5 Nxc5 10. e5 Nfd7 11. exd6 0-0 12. 0-0-0 exd6 13. Bh6 Bxh6 14. Qxh6 Ne5 15. g4 hxg4 16. h5 Re8 17. hxg6 Nxg6 18. Nf4 Qf6 19. Nxg6 fxg6 20. Bc4+ Be6 21. Rxd6 Qg7 22. Qg5 b5 23. Bd5 Rad8 24. Rxd8 1-0

[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "3"]
[White "Rosero, Jefferson"]
[Black "Guevara Ruiz, Santiago Jose"]
[Result "0-1"]
[ECO "A22"]
[WhiteElo "2087"]
[BlackElo "1920"]
[PlyCount "48"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. c4 e5 2. Nc3 Nf6 3. e3 c6 4. g4 d5 5. g5 Ne4 6. Nxe4 dxe4 7. h4 h6 8. Qc2 Bf5 9. Bh3 Bxh3 10. Nxh3 Qd3 11. Qxd3 exd3 12. f4 Nd7 13. Nf2 exf4 14. exf4 hxg5 15. fxg5 Ne5 16. b3 0-0-0 17. Bb2 Nf3+ 18. Kd1 Rxh4 19. Rxh4 Nxh4 20. Be5 Nf3 21. Bf4 Bc5 22. Ng4 Re8 23. Be3 Rh8 24. Kc1 Ba3+ 0-1

[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "5"]
[White "Rosero, Jefferson"]
[Black "Jimenez Salas, Maria Teresa"]
[Result "1/2-1/2"]
[ECO "A00"]
[WhiteElo "2087"]
[BlackElo "1900"]
[PlyCount "116"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. b4 d5 2. Bb2 Nf6 3. a3 Bg4 4. h3 Bh5 5. g4 Bg6 6. d3 Nbd7 7. f4 e6 8. Nf3 Bd6 9. Ne5 c6 10. Nd2 Nxe5 11. fxe5 Nd7 12. Nf3 Bc7 13. Qd2 a5 14. Rb1 axb4 15. axb4 f6 16. Qe3 Qe7 17. Bg2 Qxb4+ 18. c3 Qe7 19. 0-0 0-0 20. exf6 Nxf6 21. Ne5 Bxe5 22. Qxe5 Nd7 23. Qc7 Rab8 24. Rxf8+ Rxf8 25. Qxb7 Qc5+ 26. Kh1 Qd6 27. Ba3 Qxa3 28. Qxd7 Qxc3 29. Rb7 Bf7 30. Rc7 c5 31. Qd6 Qe1+ 32. Kh2 Qxe2 33. Qxc5 Qxd3 34. Rc8 Be8 35. Qe7 Qg6 36. Rd8 Qf7 37. Qd6 Bb5 38. Rxf8+ Qxf8 39. Qxe6+ Kh8 40. Qxd5 Qb8+ 41. Kh1 h6 42. g5 hxg5 43. Qxg5 Qe8 44. Qh4+ Kg8 45. Bd5+ Kf8 46. Qh8+ Ke7 47. Qxg7+ Kd6 48. Qd4 Qe1+ 49. Kh2 Qe5+ 50. Qxe5+ Kxe5 51. Ba2 Kf6 52. Kg3 Kg7 53. Kg4 Kh8 54. Kg5 Bd7 55. h4 Be8 56. Be6 Bc6 57. h5 Be8 58. h6 Bc6 1/2-1/2

[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "1"]
[White "Rosero, Jefferson"]
[Black "Sanchez Bermudez, Jeronimo"]
[Result "1-0"]
[ECO "D10"]
[WhiteElo "2087"]
[BlackElo "1634"]
[PlyCount "67"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. e4 c5 2. d4 cxd4 3. c3 Nc6 4. cxd4 d5 5. Nc3 dxe4 6. d5 Ne5 7. Qa4+ Bd7 8. Qxe4 Ng6 9. Bd3 Nf6 10. Qe2 e6 11. dxe6 Bxe6 12. Nf3 a6 13. Ng5 Qe7 14. 0-0 Bg4 15. Qc2 Be6 16. f4 Qc5+ 17. Kh1 Bg4 18. Qb3 Qc7 19. Bc4 0-0-0 20. Nxf7 Bd6 21. Nxh8 Rxh8 22. Be3 Nxf4 23. Rac1 Ng6 24. Nb5 Qb8 25. Be6+ Kd8 26. Nxd6 Qxd6 27. Bb6+ Ke7 28. Bc5 Bxe6 29. Bxd6+ Kxd6 30. Qb6+ Ke7 31. Rc7+ Kf8 32. Qd6+ Kg8 33. Qxe6+ Kf8 34. Qf7# 1-0

[Event "American Continental Blitz 18th"]
[Site "Medellin"]
[Date "2024.05.29"]
[Round "8"]
[White "Zapata Cuartas, Juan Carlos"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "A60"]
[WhiteElo "1963"]
[BlackElo "2087"]
[PlyCount "121"]
[EventDate "2024.05.29"]
[EventType "swiss (blitz)"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 220 Extra"]
[Source "ChessBase"]
[SourceDate "2024.07.31"]
[SourceVersion "1"]
[SourceVersionDate "2024.07.31"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 Be7 7. e4 0-0 8. Bd3 Re8 9. 0-0 Bg4 10. Be2 Bf8 11. Nd2 Bxe2 12. Qxe2 Nbd7 13. a4 g6 14. Nc4 Nb6 15. Qd3 Nxc4 16. Qxc4 Qd7 17. h3 Bg7 18. Be3 Qe7 19. f3 Nd7 20. Bf4 g5 21. Bg3 Ne5 22. Qe2 Ng6 23. f4 Bd4+ 24. Kh1 Bxc3 25. bxc3 Qxe4 26. Qxe4 Rxe4 27. fxg5 Re3 28. Rf3 Rae8 29. Bxd6 Rxf3 30. gxf3 Rd8 31. Bxc5 Rxd5 32. Bxa7 Rxg5 33. Rb1 Nh4 34. Rxb7 Nxf3 35. Bd4 Nxd4 36. cxd4 Ra5 37. Rb4 Kg7 38. Kg2 Kf6 39. Kf3 Rh5 40. Kg4 Rg5+ 41. Kf4 Rh5 42. Rb3 Rh4+ 43. Kg3 Rxd4 44. Ra3 Rd6 45. a5 Ra6 46. Kf4 Ke6 47. Ke4 Kd6 48. Rf3 Ke6 49. Rf5 f6 50. Rb5 Kd7 51. Kf5 Kc6 52. Rb6+ Rxb6 53. axb6 Kxb6 54. Kxf6 Kc6 55. Kg7 h5 56. Kg6 h4 57. Kg5 Kd6 58. Kxh4 Ke7 59. Kg5 Kf7 60. Kh6 Kg8 61. Kg6 1/2-1/2

[Event "Valle Region-ch U20"]
[Site "Cali"]
[Date "2017.02.18"]
[Round "4.3"]
[White "Rodriguez Jimenez, Juan Jose"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "A42"]
[WhiteElo "1653"]
[BlackElo "2087"]
[PlyCount "40"]
[EventDate "2017.02.17"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. d4 g6 2. c4 Bg7 3. Nc3 d6 4. e4 Nd7 5. Be2 e5 6. d5 Ne7 7. h4 h6 8. h5 g5 9. g4 Nf6 10. f3 c6 11. Be3 a6 12. Nh3 Kf8 13. Nf2 Rb8 14. a4 Qc7 15. 0-0 Neg8 16. Nh1 Ne7 17. Ng3 Bd7 18. Qd2 Nc8 19. b4 Kg8 20. Kg2 Bf8 1/2-1/2

[Event "Valle Region-ch U20"]
[Site "Cali"]
[Date "2017.02.18"]
[Round "3.4"]
[White "Rosero, Jefferson"]
[Black "Gonzalez Velasco, Leandro"]
[Result "1-0"]
[ECO "A35"]
[WhiteElo "2087"]
[BlackElo "1602"]
[PlyCount "30"]
[EventDate "2017.02.17"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. c4 c5 2. Nc3 Nf6 3. e3 g6 4. Nf3 Bg7 5. Be2 0-0 6. 0-0 Nc6 7. d4 cxd4 8. Nxd4 d6 9. Bf3 Nxd4 10. exd4 Be6 11. b3 Qa5 12. Bd2 Rab8 13. Re1 b6 14. Nd5 Qa6 15. Nxe7+ Kh8 1-0

[Event "Valle Region-ch U20"]
[Site "Cali"]
[Date "2017.02.18"]
[Round "5.4"]
[White "Rosero, Jefferson"]
[Black "Oliveros, Camilo"]
[Result "0-1"]
[ECO "B19"]
[WhiteElo "2087"]
[BlackElo "2030"]
[PlyCount "49"]
[EventDate "2017.02.17"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. Nf3 Nd7 7. h4 h6 8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 Ngf6 11. Bd2 e6 12. 0-0-0 Bd6 13. Rde1 0-0 14. Ne5 c5 15. Nxd7 Qxd7 16. Rh4 Be7 17. Ne4 Qa4 18. Nc3 Qc6 19. Re3 cxd4 20. Rxd4 Bc5 21. Rc4 Rad8 22. Qe2 Bxe3 23. fxe3 Qd6 24. Ne4 Nxe4 25. Rxe4 0-1

[Event "Valle Region-ch U20"]
[Site "Cali"]
[Date "2017.02.17"]
[Round "2.7"]
[White "Lopez Rayo, Santiago"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B21"]
[WhiteElo "1547"]
[BlackElo "2087"]
[PlyCount "27"]
[EventDate "2017.02.17"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 Nc6 5. Bc4 a6 6. Nf3 d6 7. Qe2 g6 8. 0-0 Bg7 9. Be3 Nf6 10. Rfd1 0-0 11. Bb3 Qc7 12. Qc4 b5 13. Qd4 Nxd4 14. Rxd4 0-1

[Event "Valle Region-ch U20"]
[Site "Cali"]
[Date "2017.02.17"]
[Round "1.3"]
[White "Rosero, Jefferson"]
[Black "Villaquiran, Miguel"]
[Result "0-1"]
[ECO "B95"]
[WhiteElo "2087"]
[BlackElo "1586"]
[PlyCount "44"]
[EventDate "2017.02.17"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f3 Be7 8. Qd2 Nc6 9. 0-0-0 Qc7 10. g4 b5 11. Nxc6 Qxc6 12. Be3 Bb7 13. g5 Nd7 14. Ne2 Ne5 15. Nd4 Nc4 16. Bxc4 Qxc4 17. Nb3 a5 18. Kb1 d5 19. Nxa5 Qa4 20. Bb6 Bb4 21. Qe2 Bxa5 22. b3 Qxa2+ 0-1

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.25"]
[Round "9"]
[White "Cofre Archibold, Nestor"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B75"]
[WhiteElo "2215"]
[BlackElo "2090"]
[PlyCount "57"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 Nc6 8. Qd2 Bd7 9. g4 h5 10. g5 Nh7 11. h4 Nf8 12. Bc4 Ne5 13. Bb3 Ne6 14. 0-0-0 Nxd4 15. Bxd4 0-0 16. Rhf1 Rc8 17. f4 Nc4 18. Bxc4 Rxc4 19. Bxg7 Kxg7 20. f5 Qa5 21. f6+ Kg8 22. fxe7 Rfc8 23. Qd5 Qxd5 24. Rxd5 Bh3 25. Rxd6 Re8 26. Rd8 Rc8 27. Rfd1 Kg7 28. Rxc8 Bxc8 29. Rd8 1-0

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.24"]
[Round "7"]
[White "Oliva Meneses, Juan Carlos"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "A58"]
[WhiteElo "2216"]
[BlackElo "2090"]
[PlyCount "95"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. bxa6 d6 6. Nc3 Bxa6 7. Nf3 g6 8. g3 Nfd7 9. e4 Bg7 10. Bxa6 Nxa6 11. 0-0 0-0 12. Bd2 c4 13. Qe2 Qc7 14. a4 Qb7 15. Qxc4 f5 16. exf5 Rxf5 17. Nd4 Rf7 18. Qc6 Qb8 19. Qxd7 Bxd4 20. Ne4 Qxb2 21. Rab1 Qc2 22. Qc6 Qxc6 23. dxc6 Rc8 24. Rbc1 Nc5 25. Nxc5 Bxc5 26. Be3 Rf5 27. Bxc5 Rxc5 28. Rxc5 dxc5 29. Kg2 Kf7 30. Kf3 Rxc6 31. Ra1 c4 32. a5 c3 33. a6 c2 34. a7 Rc3+ 35. Ke2 c1Q 36. Rxc1 Ra3 37. Rc7 Ke6 38. Kd2 h5 39. h4 Kd6 40. Rb7 Ke6 41. Kc2 Kd6 42. Kb2 Ra6 43. Kc3 Ra4 44. Kd3 Ke6 45. Ke3 Kf6 46. Kd3 Ke6 47. Kc3 Ra1 48. Kd4 1-0

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.24"]
[Round "8"]
[White "Rosero, Jefferson"]
[Black "Castano Orrego, Simon"]
[Result "1-0"]
[ECO "B90"]
[WhiteElo "2090"]
[BlackElo "1687"]
[PlyCount "51"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. h3 e5 7. Nde2 Be6 8. g4 h6 9. Bg2 Be7 10. f4 exf4 11. Nxf4 Nc6 12. Be3 Ne5 13. Qd4 Rc8 14. 0-0 Nc4 15. Bf2 Qc7 16. Rae1 0-0 17. Nd3 Nxb2 18. Nd5 Bxd5 19. exd5 Nc4 20. Bh4 Qd8 21. g5 hxg5 22. Bxg5 Re8 23. Qh4 Nxd5 24. Bxd5 Bxg5 25. Bxf7+ Kf8 26. Qh8# 1-0

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.23"]
[Round "6"]
[White "Rosero, Jefferson"]
[Black "Squella Lavin, Carlos Felipe"]
[Result "1/2-1/2"]
[ECO "C16"]
[WhiteElo "2090"]
[BlackElo "2221"]
[PlyCount "171"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 b6 5. Bd2 Nc6 6. Qg4 Bf8 7. a3 Qd7 8. Be3 Bb7 9. Bd3 Nge7 10. Qf3 Ng6 11. h4 0-0-0 12. Nce2 Qe8 13. Ng3 Be7 14. Qg4 h5 15. Nxh5 Nxh4 16. Bg5 Ng6 17. 0-0-0 Ngxe5 18. dxe5 Nxe5 19. Qg3 f6 20. Nxg7 Qf7 21. Bh6 Rdg8 22. Nf3 Nxd3+ 23. cxd3 Bf8 24. Nd4 Bxg7 25. Bxg7 Rxh1 26. Rxh1 Rxg7 27. Rh8+ Kd7 28. Qh3 Bc8 29. Rh5 c6 30. Rh8 c5 31. Qh2 cxd4 32. Qb8 Rg8 33. Rh7 Qxh7 34. Qxa7+ Kd6 35. Qxh7 Rxg2 36. Qh4 Ke5 37. Qh5+ Kd6 38. Qh8 Ba6 39. Qxf6 Bxd3 40. Qxd4 Be4 41. Qxb6+ Ke5 42. Qc5 Rg1+ 43. Kd2 Rb1 44. a4 Rxb2+ 45. Ke3 Rb3+ 46. Kd2 Rb2+ 47. Ke1 Rc2 48. Qe3 Rc4 49. a5 d4 50. Qg5+ Bf5 51. Qg3+ Ke4 52. a6 Ra4 53. Qb8 Ra1+ 54. Kd2 Ra2+ 55. Kc1 d3 56. Qb7+ Kf4 57. Qc7+ Kg5 58. Qg7+ Kh5 59. Qf7+ Kg4 60. a7 Kf3 61. Qh5+ Kg2 62. Qg5+ Kf1 63. Qe3 d2+ 64. Kd1 Kg2 65. Qg3+ Kf1 66. Qe3 Kg2 67. Qg3+ Kf1 68. f4 Be4 69. Qh3+ Kf2 70. Qh2+ Ke3 71. Qe2+ Kxf4 72. Qc4 Rxa7 73. Kxd2 Rd7+ 74. Ke1 e5 75. Qf1+ Bf3 76. Qc4+ e4 77. Kf2 Rd2+ 78. Ke1 Rg2 79. Kf1 Rg5 80. Kf2 Rg2+ 81. Kf1 Rg5 82. Kf2 Rf5 83. Qc7+ Re5 84. Qf7+ Kg5 85. Ke3 Rf5 86. Qg7+ 1/2-1/2

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.22"]
[Round "5"]
[White "Escalante Ramirez, Brian Sebastian"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "B33"]
[WhiteElo "2300"]
[BlackElo "2090"]
[PlyCount "64"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Nd5 Nxd5 8. exd5 Nb8 9. Qf3 a6 10. Qa3 Be7 11. Bg5 f6 12. Bd2 0-0 13. c4 f5 14. Be2 f4 15. Bd3 f3 16. gxf3 Rxf3 17. Bxh7+ Kxh7 18. Qxf3 axb5 19. Rg1 Bf8 20. Bg5 Qe8 21. cxb5 Nd7 22. b4 e4 23. Qh3+ Kg8 24. Qe6+ Qxe6 25. dxe6 Ne5 26. e7 Nf3+ 27. Ke2 Nxg1+ 28. Rxg1 Bd7 29. exf8Q+ Kxf8 30. Bf4 Rxa2+ 31. Ke3 Bxb5 32. Bxd6+ Kf7 1/2-1/2

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.22"]
[Round "4"]
[White "Rosero, Jefferson"]
[Black "Correa, Daniel"]
[Result "1-0"]
[ECO "B76"]
[WhiteElo "2090"]
[BlackElo "1716"]
[PlyCount "59"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 0-0 8. Qd2 Nc6 9. 0-0-0 Bd7 10. Kb1 a6 11. g4 Rc8 12. g5 Nh5 13. Nce2 Ne5 14. Ng3 Nc4 15. Bxc4 Rxc4 16. b3 Rc7 17. Nxh5 gxh5 18. Nf5 Bxf5 19. exf5 Rc6 20. Rhg1 Qd7 21. f6 Bh8 22. Qd3 e6 23. Rg3 Rfc8 24. c4 e5 25. Qe4 R8c7 26. f4 exf4 27. Bxf4 Rc8 28. Re3 R6c7 29. Qd5 Qg4 30. Rde1 1-0

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.21"]
[Round "3"]
[White "Acosta, Pablo Ismael"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "A37"]
[WhiteElo "2380"]
[BlackElo "2090"]
[PlyCount "91"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. c4 c5 2. g3 g6 3. Bg2 Nc6 4. Nc3 Bg7 5. Nf3 e6 6. 0-0 Nge7 7. d3 0-0 8. Ne4 b6 9. Nd6 Qc7 10. Bf4 e5 11. Nb5 Qb8 12. Bg5 Bb7 13. Qc1 Re8 14. e4 a6 15. Nc3 Qd6 16. Nd5 Nxd5 17. exd5 Nd4 18. Nxd4 cxd4 19. f4 Qb4 20. f5 f6 21. Bd2 Qf8 22. h4 Rac8 23. Be4 Qf7 24. Qd1 gxf5 25. Rxf5 d6 26. Rh5 Rc7 27. Bxh7+ Kf8 28. Qe2 e4 29. Bxe4 Bc8 30. Bf4 Rd7 31. Qf3 Rdd8 32. Bf5 Bxf5 33. Rxf5 Qg6 34. g4 Kg8 35. h5 Qh7 36. Rf1 Rd7 37. Qf2 Rde7 38. Qxd4 Re2 39. Bxd6 Rc2 40. Kh1 Ree2 41. Qxb6 Qh6 42. Qb8+ Kh7 43. Bf4 Rxb2 44. Qxb2 Rxb2 45. Bxh6 Kxh6 46. d6 1-0

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.21"]
[Round "2"]
[White "Rosero, Jefferson"]
[Black "Echeverry, Jose Miguel"]
[Result "1-0"]
[ECO "C16"]
[WhiteElo "2090"]
[BlackElo "1807"]
[PlyCount "61"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 Qd7 5. Qg4 f5 6. Qg3 b6 7. a3 Bxc3+ 8. Qxc3 Ne7 9. a4 Ba6 10. Ne2 0-0 11. b3 c5 12. dxc5 bxc5 13. Ba3 Rc8 14. Bxc5 Bxe2 15. Bxe2 Qc7 16. b4 a5 17. Qa3 axb4 18. Bxb4 Nec6 19. 0-0 Qxe5 20. Rfe1 Qf4 21. Bd6 Qg5 22. Qb2 f4 23. Qb7 Rd8 24. Bxb8 Nd4 25. Qxa8 f3 26. Bf1 fxg2 27. Bxg2 Rf8 28. Qa7 e5 29. Bxe5 Nf3+ 30. Kh1 Nxe5 31. Qd4 1-0

[Event "Pan American-ch U20"]
[Site "Guatape"]
[Date "2016.06.20"]
[Round "1"]
[White "Vazquez, Guillermo"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B53"]
[WhiteElo "2401"]
[BlackElo "2090"]
[PlyCount "59"]
[EventDate "2016.06.20"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2017"]
[Source "ChessBase"]
[SourceDate "2016.10.25"]
[SourceVersion "1"]
[SourceVersionDate "2016.10.25"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 Nf6 5. Bb5+ Bd7 6. c4 a6 7. Bxd7+ Nfxd7 8. 0-0 Nc6 9. Qe3 g6 10. Nc3 Bg7 11. Bd2 Rc8 12. Rac1 0-0 13. b3 Re8 14. Rfd1 h6 15. h3 Nde5 16. Ne1 e6 17. Qg3 g5 18. Be3 Qe7 19. Nf3 Rcd8 20. Nd4 Ng6 21. Rc2 Be5 22. Qg4 Qf6 23. Rcd2 Kg7 24. Nce2 Nxd4 25. Nxd4 Kh7 26. Nf3 Nf4 27. h4 gxh4 28. Qxh4 Ng6 29. Qxh6+ Kg8 30. Bg5 1-0

[Event "COL-ch U20"]
[Site "Medellin"]
[Date "2016.03.18"]
[Round "5"]
[White "De la Rosa Povea, Miguel Angel"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B33"]
[WhiteElo "1725"]
[BlackElo "2120"]
[PlyCount "74"]
[EventDate "2016.03.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Nf3 Bb4 7. Bc4 0-0 8. 0-0 Bxc3 9. bxc3 Nxe4 10. Qd3 Nc5 11. Qe3 d6 12. Ba3 Qa5 13. Bb2 Be6 14. Bxe6 fxe6 15. Rfd1 Rad8 16. Ng5 h6 17. Ne4 Nxe4 18. Qxe4 Qb6 19. Ba3 Qxf2+ 20. Kh1 Rf4 21. Qg6 Rf6 22. Qd3 d5 23. Rf1 Qh4 24. Qb5 Qc4 25. Qxc4 dxc4 26. Rxf6 gxf6 27. Kg1 Rd2 28. Rc1 b6 29. Kf1 f5 30. h3 e4 31. Bb2 Ne5 32. Ba3 Kf7 33. Bb4 Ng6 34. g3 Ne5 35. a4 Nf3 36. a5 e3 37. axb6 Rf2# 0-1

[Event "COL-ch U20"]
[Site "Medellin"]
[Date "2016.03.18"]
[Round "4"]
[White "Rosero, Jefferson"]
[Black "Posada, Juan Manuel"]
[Result "0-1"]
[ECO "B90"]
[WhiteElo "2120"]
[BlackElo "2008"]
[PlyCount "86"]
[EventDate "2016.03.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. h3 g6 7. Bg5 Bg7 8. Qd2 Nbd7 9. 0-0-0 h6 10. Be3 b5 11. a3 Bb7 12. Bd3 Rc8 13. Nb3 Ne5 14. Rhe1 Nc4 15. Bxc4 bxc4 16. e5 cxb3 17. exf6 Bxf6 18. Bd4 Bxd4 19. Qxd4 0-0 20. cxb3 Re8 21. Re3 Qa5 22. b4 Qf5 23. g4 Qxf2 24. Rxe7 Qxd4 25. Rxe8+ Rxe8 26. Rxd4 Re3 27. h4 Rh3 28. g5 hxg5 29. hxg5 Rg3 30. Rxd6 Rxg5 31. Rb6 Bf3 32. Rxa6 Re5 33. Rf6 Bb7 34. a4 g5 35. Kd2 g4 36. Ne2 Kg7 37. Rf4 f5 38. Ng3 Kg6 39. b5 Kg5 40. Rxf5+ Rxf5 41. Nxf5 Kxf5 42. a5 Kf4 43. a6 Bc8 0-1

[Event "COL-ch U20"]
[Site "Medellin"]
[Date "2016.03.17"]
[Round "2"]
[White "Rosero, Jefferson"]
[Black "Barrera Hincapie, Felipe"]
[Result "1-0"]
[ECO "B01"]
[WhiteElo "2120"]
[BlackElo "1740"]
[PlyCount "31"]
[EventDate "2016.03.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 d5 2. exd5 Qxd5 3. Nf3 Nf6 4. d4 Bg4 5. Be2 Nc6 6. c4 Qh5 7. Be3 0-0-0 8. Qa4 e5 9. d5 Nd4 10. Bxd4 exd4 11. Qxa7 Bb4+ 12. Kf1 Bxf3 13. Bxf3 Qe5 14. Qa8+ Kd7 15. Qa4+ Kc8 16. Qxb4 1-0

[Event "COL-ch U20"]
[Site "Medellin"]
[Date "2016.03.17"]
[Round "3"]
[White "Ruiz Castillo, Joshua Daniel"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B53"]
[WhiteElo "2374"]
[BlackElo "2120"]
[PlyCount "113"]
[EventDate "2016.03.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 Nd7 5. c4 Ngf6 6. Nc3 g6 7. Bg5 Bg7 8. Be2 h6 9. Bc1 0-0 10. 0-0 Qa5 11. Qd2 Rd8 12. Qc2 Ne5 13. Nxe5 Qxe5 14. Be3 g5 15. Rad1 Ng4 16. Bxg4 Bxg4 17. Rd5 Qf6 18. Rb5 Be6 19. Rxb7 Bxc4 20. Rd1 Rdc8 21. Qb1 Qe6 22. Nd5 Bxd5 23. exd5 Qg4 24. h3 Qa4 25. b3 Qa6 26. Rxe7 Re8 27. Rc7 Qe2 28. Rd2 Qh5 29. Qf5 Re5 30. Qd7 Rae8 31. Rc8 Rxc8 32. Qxc8+ Kh7 33. Qc2+ Kg8 34. Qd1 Qxd1+ 35. Rxd1 a6 36. g4 Re4 37. Kg2 a5 38. Kf3 Rb4 39. Rd3 a4 40. Bd2 axb3 41. axb3 Rb8 42. b4 Be5 43. Ke4 Rc8 44. b5 Rc2 45. b6 Rb2 46. Be3 Kg7 47. Ra3 Kg6 48. Ra7 Rb4+ 49. Kd3 f5 50. gxf5+ Kxf5 51. Rf7+ Kg6 52. Rc7 Kf5 53. b7 Rb3+ 54. Kc2 Rb2+ 55. Kc1 Rb5 56. Ba7 Bf4+ 57. Kc2 1-0

[Event "COL-ch U20"]
[Site "Medellin"]
[Date "2016.03.16"]
[Round "1"]
[White "Gomez Rondon, Samuel"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B79"]
[WhiteElo "1571"]
[BlackElo "2120"]
[PlyCount "36"]
[EventDate "2016.03.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 0-0 8. Qd2 Nc6 9. Bc4 Bd7 10. h4 h5 11. 0-0-0 Ne5 12. Bb3 Qa5 13. Kb1 Rfc8 14. Nd5 Qxd2 15. Nxf6+ Bxf6 16. Rxd2 a5 17. Bd5 Nc4 18. Bxc4 Rxc4 0-1

[Event "Cali Region-ch"]
[Site "Cali"]
[Date "2016.03.12"]
[Round "3"]
[White "Morales, Jhon Alexander"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "A37"]
[WhiteElo "2350"]
[BlackElo "2120"]
[PlyCount "105"]
[EventDate "2016.03.11"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. c4 c5 2. Nf3 Nc6 3. g3 g6 4. Bg2 Bg7 5. 0-0 Nh6 6. Nc3 Nf5 7. Rb1 h5 8. a3 b6 9. b4 Rb8 10. Ne4 Qc7 11. d3 d6 12. Bb2 Bxb2 13. Rxb2 a5 14. bxc5 bxc5 15. Rxb8 Qxb8 16. Qa1 0-0 17. Rb1 Qa7 18. Nc3 Bd7 19. Nb5 Qa6 20. e3 Rb8 21. Nc7 Qc8 22. Nd5 Rb7 23. Rb6 Qb8 24. Qb2 Rxb6 25. Qxb6 Qxb6 26. Nxb6 Be8 27. Kf1 e6 28. Ke2 Kf8 29. Bh3 Nh6 30. Nc8 d5 31. cxd5 exd5 32. Nb6 Na7 33. Nxd5 Nb5 34. a4 Nd6 35. Nb6 Ke7 36. Ne5 f6 37. Nec4 Nxc4 38. Nxc4 Bxa4 39. Nxa5 Bb5 40. Kd2 Nf7 41. Nb7 Ne5 42. Nxc5 Nf3+ 43. Kc3 Nxh2 44. Nb3 Nf3 45. Nd4 Ng1 46. Bg2 Bd7 47. Kd2 g5 48. Ke1 Nh3 49. f4 Bg4 50. Kf1 Kd6 51. Bf3 f5 52. Bxg4 fxg4 53. Ne2 1-0

[Event "Cali Region-ch"]
[Site "Cali"]
[Date "2016.03.12"]
[Round "5"]
[White "Plazas, Alfonso"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "A34"]
[WhiteElo "1988"]
[BlackElo "2120"]
[PlyCount "22"]
[EventDate "2016.03.11"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. c4 c5 2. Nf3 Nc6 3. g3 Nf6 4. Nc3 d6 5. Bg2 Bf5 6. 0-0 e6 7. d3 Be7 8. Bd2 0-0 9. e4 Bg4 10. h3 Bxf3 11. Qxf3 Nd4 0-1

[Event "Cali Region-ch"]
[Site "Cali"]
[Date "2016.03.12"]
[Round "4"]
[White "Rosero, Jefferson"]
[Black "Palechor, Andres Fernando"]
[Result "1-0"]
[ECO "C00"]
[WhiteElo "2120"]
[BlackElo "1869"]
[PlyCount "33"]
[EventDate "2016.03.11"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 e6 2. Qe2 c5 3. g3 d5 4. exd5 Qxd5 5. Nf3 Nc6 6. c3 Nf6 7. Bg2 Be7 8. 0-0 Qd7 9. Rd1 0-0 10. d4 cxd4 11. Nxd4 Rd8 12. Bf3 Nxd4 13. Rxd4 Qc7 14. Bf4 Bd6 15. Qd2 Ne8 16. Na3 Bxf4 17. Rxd8 1-0

[Event "Cali Region-ch"]
[Site "Cali"]
[Date "2016.03.11"]
[Round "1"]
[White "Bedoya, Gustavo"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "E90"]
[BlackElo "2120"]
[PlyCount "30"]
[EventDate "2016.03.11"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. d4 g6 2. c4 Nf6 3. Nf3 c5 4. Nc3 Bg7 5. d5 d6 6. e4 Bg4 7. h3 Bxf3 8. Qxf3 Na6 9. a3 Nd7 10. Qg3 h5 11. Bg5 Qb6 12. Rb1 Qb3 13. f4 h4 14. Qd3 Bd4 15. f5 Ne5 0-1

[Event "Cali Region-ch"]
[Site "Cali"]
[Date "2016.03.11"]
[Round "2"]
[White "Rosero, Jefferson"]
[Black "Delgado, Harold"]
[Result "1-0"]
[ECO "B41"]
[WhiteElo "2120"]
[PlyCount "35"]
[EventDate "2016.03.11"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 171 Extra"]
[Source "ChessBase"]
[SourceDate "2016.04.26"]
[SourceVersion "1"]
[SourceVersionDate "2016.04.26"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. c4 Qc7 6. Be2 Nf6 7. Nc3 Bb4 8. Nc2 Bd6 9. Be3 Bc5 10. Qd2 Bxe3 11. Qxe3 d6 12. Qg3 Ke7 13. 0-0 Nbd7 14. Rad1 Ne5 15. Ne3 h5 16. f4 Neg4 17. Bxg4 Nxg4 18. Ncd5+ 1-0

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.07.03"]
[Round "9"]
[White "Bobadilla Viera, Jorge Samuel"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "A43"]
[WhiteElo "2169"]
[BlackElo "2023"]
[PlyCount "52"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. d4 Nf6 2. Nc3 c5 3. d5 e6 4. e4 d6 5. Nf3 Be7 6. Bb5+ Kf8 7. a4 h6 8. Bd3 Na6 9. Bc4 Nb4 10. 0-0 exd5 11. Bxd5 Nfxd5 12. Nxd5 Nxd5 13. Qxd5 Qb6 14. Qd3 Be6 15. c4 Bf6 16. Bf4 Rd8 17. Rfd1 Ke7 18. Rab1 Rd7 19. Ne1 Be5 20. Bd2 Rf8 21. f4 Bd4+ 22. Kh1 f5 23. Bc3 Bxc3 24. Qxc3 fxe4 25. Qxg7+ Rf7 26. Qxh6 Bxc4 0-1

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.07.02"]
[Round "7"]
[White "Suarez Ohiggins, Luis"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "E61"]
[WhiteElo "2054"]
[BlackElo "2023"]
[PlyCount "94"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. e3 g6 4. Nf3 Bg7 5. Be2 cxd4 6. exd4 d6 7. Nc3 0-0 8. 0-0 Bg4 9. h3 Bxf3 10. Bxf3 Nc6 11. Re1 Re8 12. b3 Nd7 13. Be3 Qa5 14. Rc1 Rad8 15. g3 h6 16. Qd2 Kh7 17. Red1 Ndb8 18. Ne2 Qf5 19. Bg2 b6 20. b4 Rc8 21. g4 Qd7 22. a3 Rc7 23. Nc3 Rcc8 24. f4 Nd8 25. Be4 e6 26. Qd3 f5 27. Bf3 Nf7 28. Ne2 Qe7 29. Bf2 Bf6 30. Rc2 Rcd8 31. Ng3 Bh4 32. Re1 Qf6 33. gxf5 gxf5 34. Kh2 Bxg3+ 35. Bxg3 e5 36. dxe5 dxe5 37. Qe3 e4 38. Be2 Nc6 39. Rd1 Rxd1 40. Bxd1 Rd8 41. Rd2 Qa1 42. Bh5 Qc1 43. Be1 Qxc4 44. Rg2 Ne7 45. Bc3 Rd3 46. Rg7+ Kh8 47. Rg3+ Qxc3 0-1

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.07.01"]
[Round "6"]
[White "Rosero, Jefferson"]
[Black "Bejar Caceres, Brayan Daniel"]
[Result "1-0"]
[ECO "B06"]
[WhiteElo "2023"]
[BlackElo "1906"]
[PlyCount "75"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. e4 g6 2. Bc4 Bg7 3. f4 d6 4. Qf3 e6 5. Ne2 Ne7 6. Nbc3 c6 7. Bb3 0-0 8. g4 d5 9. d3 c5 10. h4 b5 11. a3 c4 12. Ba2 Nd7 13. h5 Bb7 14. hxg6 fxg6 15. Qh3 Nc5 16. f5 exf5 17. Qxh7+ Kf7 18. Bh6 Rg8 19. exf5 gxf5 20. Rh5 Ne6 21. Rxf5+ Nxf5 22. Qxf5+ Qf6 23. Bxg7 Rxg7 24. Nxb5 cxd3 25. cxd3 Qxf5 26. Nd6+ Kf6 27. gxf5 Nf4 28. Kf2 Nxd3+ 29. Ke3 Ba6 30. Bxd5 Re7+ 31. Ne4+ Kxf5 32. Bxa8 Nxb2 33. Nd4+ Kg6 34. Rg1+ Kh7 35. Bd5 Bc4 36. Bxc4 Nxc4+ 37. Kf4 Rb7 38. Nf6+ 1-0

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.07.01"]
[Round "5"]
[White "Valenzuela Martinez, Hermes"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "B01"]
[WhiteElo "1959"]
[BlackElo "2023"]
[PlyCount "62"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. Bc4 Nf6 5. d4 Bg4 6. f3 Bf5 7. Nge2 c6 8. 0-0 e6 9. Bf4 Nbd7 10. Ng3 Bg6 11. Nce4 0-0-0 12. c3 e5 13. Be3 Qc7 14. Qc1 Nb6 15. Bb3 Nfd5 16. dxe5 Nxe3 17. Qxe3 h5 18. f4 h4 19. Ne2 Nd5 20. Bxd5 cxd5 21. Nd2 Bc5 22. Nd4 Bf5 23. a4 a6 24. b4 Ba7 25. h3 Rhe8 26. Rf3 Bg6 27. Qe1 Re7 28. b5 a5 29. Qxh4 Be4 30. Re3 f6 31. e6 Ree8 1/2-1/2

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.06.30"]
[Round "4"]
[White "Rosero, Jefferson"]
[Black "Villegas, Franco"]
[Result "0-1"]
[ECO "B32"]
[WhiteElo "2023"]
[BlackElo "2138"]
[PlyCount "46"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Qb6 5. Nb5 a6 6. Be3 Qa5+ 7. N5c3 Nf6 8. Nd2 e6 9. Nc4 Qc7 10. Bb6 Qb8 11. Qd2 Bb4 12. Qg5 0-0 13. Bd3 d5 14. Nd2 d4 15. Ne2 h6 16. Qg3 Bxd2+ 17. Kxd2 e5 18. Bc5 Re8 19. f4 b6 20. fxe5 Nh5 21. Qf3 bxc5 22. Qxh5 c4 23. Raf1 Be6 0-1

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.06.29"]
[Round "3"]
[White "Cuellar, Diego"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B75"]
[WhiteElo "2332"]
[BlackElo "2023"]
[PlyCount "71"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 d6 3. Nge2 Nf6 4. d4 cxd4 5. Nxd4 g6 6. Be3 Bg7 7. f3 Nc6 8. Qd2 Bd7 9. 0-0-0 Rc8 10. h4 h5 11. Kb1 a6 12. Nde2 Ne5 13. Nf4 Be6 14. Nxe6 fxe6 15. Bd4 Bh6 16. Qf2 Nfd7 17. Bd3 Qa5 18. Rhf1 Rf8 19. Qe1 b5 20. Ne2 Qc7 21. Bc3 Nxd3 22. cxd3 Nc5 23. Nd4 e5 24. Ba5 Qa7 25. Nc2 Ne6 26. Bd2 Nf4 27. Be3 Qc7 28. Qd2 Bg7 29. Rc1 Qb7 30. d4 Ne6 31. d5 Nc5 32. Nb4 Kf7 33. Nc6 Nd7 34. Rc2 Rc7 35. Rfc1 Rfc8 36. Nd8+ 1-0

[Event "Pan American-ch U18"]
[Site "Cali"]
[Date "2015.06.29"]
[Round "2"]
[White "Rosero, Jefferson"]
[Black "Jimenez Garcia, Emanuel"]
[Result "1-0"]
[ECO "B41"]
[WhiteElo "2023"]
[BlackElo "2210"]
[PlyCount "111"]
[EventDate "2015.06.28"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2016"]
[Source "ChessBase"]
[SourceDate "2015.10.08"]
[SourceVersion "1"]
[SourceVersionDate "2015.10.08"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 a6 3. d4 cxd4 4. Nxd4 e6 5. c4 Nf6 6. Qe2 d6 7. g3 e5 8. Nc2 Bg4 9. Qd3 Nbd7 10. f3 Be6 11. Be3 Rc8 12. b3 Be7 13. Nc3 Qc7 14. Nb4 0-0 15. Qd2 Nc5 16. Bg5 Qa5 17. Nbd5 Bxd5 18. Nxd5 Qxd2+ 19. Bxd2 Nxd5 20. cxd5 f5 21. exf5 Rce8 22. b4 Na4 23. Bd3 Nb2 24. Be4 Nc4 25. h4 Rc8 26. Ke2 Bd8 27. Bg5 Bb6 28. Rac1 h6 29. Be7 Rfe8 30. Bd3 Rxe7 31. Rxc4 Rxc4 32. Bxc4 Rc7 33. Bd3 Bd4 34. Rd1 Rc3 35. Rd2 b5 36. g4 Ra3 37. Rc2 Bc3 38. g5 hxg5 39. hxg5 Kf7 40. Be4 Ke7 41. Kf2 Bd4+ 42. Kg3 Rc3 43. Rh2 Rc1 44. f6+ gxf6 45. Rh7+ Kf8 46. gxf6 Rg1+ 47. Kh2 Rg5 48. Kh3 Be3 49. Rd7 Bf4 50. Rxd6 Kf7 51. Rxa6 Rg3+ 52. Kh4 Rg2 53. Bd3 Rb2 54. Kh5 Rh2+ 55. Kg4 Rb2 56. Kf5 1-0

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.18"]
[Round "7"]
[White "Rosero, Jefferson"]
[Black "Torres Rojas, Yuber Andres"]
[Result "1-0"]
[ECO "C50"]
[WhiteElo "1925"]
[BlackElo "2022"]
[PlyCount "55"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. 0-0 d6 5. c3 Qf6 6. d3 Bg4 7. Bg5 Qg6 8. Nbd2 h5 9. b4 Bb6 10. a4 a5 11. Bb5 Nge7 12. Kh1 0-0 13. Bc4 Rae8 14. Be3 Bxe3 15. fxe3 axb4 16. cxb4 Nxb4 17. Qb3 Bxf3 18. Nxf3 d5 19. exd5 Qd6 20. e4 Rb8 21. Nxe5 Qxe5 22. Qxb4 b6 23. Qd2 c5 24. Qf4 Qd4 25. d6 Ng6 26. Bxf7+ Kh8 27. Qf5 Rb7 28. Qxh5# 1-0

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.17"]
[Round "6"]
[White "Rodriguez Velasco, German Enrique"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "D30"]
[WhiteElo "1959"]
[BlackElo "1925"]
[PlyCount "110"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. c4 Nf6 2. g3 e6 3. Bg2 d5 4. Nf3 dxc4 5. Qa4+ c6 6. Qxc4 b5 7. Qc2 Bb7 8. d4 Nbd7 9. 0-0 c5 10. Bg5 Qb6 11. a4 cxd4 12. axb5 Ne4 13. Bf4 Bd6 14. Bxd6 Nxd6 15. Nbd2 e5 16. Bh3 Rd8 17. Bxd7+ Rxd7 18. Nxe5 Rc7 19. Qa4 0-0 20. Qxa7 Qxb5 21. Qxd4 Nf5 22. Qf4 Rc5 23. Nd3 Rd5 24. Ra4 Rfd8 25. Rb4 Qc6 26. Rc1 Rc5 27. Rxb7 Rxc1+ 28. Nxc1 Qxb7 29. Ncb3 Ne7 30. Qf3 Qc8 31. Kg2 Ng6 32. Ne4 h6 33. Qc3 Qg4 34. f3 Qd7 35. Nbd2 f5 36. Qb3+ Qf7 37. Qb6 Rd7 38. Nd6 Qe6 39. N2c4 Qxe2+ 40. Qf2 Qe6 41. Qc5 f4 42. Ne4 Rd1 43. Ncd6 fxg3 44. hxg3 Kh7 45. Qh5 Rd5 46. Qh3 Qe5 47. Nf7 Qxb2+ 48. Nf2 Qf6 49. Nxh6 gxh6 50. Qc8 Rd2 51. Qc7+ Qg7 52. Qa5 Qd4 53. Qc7+ Kg8 54. Qb8+ Nf8 55. Qb3+ Kh8 0-1

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.16"]
[Round "5"]
[White "Rosero, Jefferson"]
[Black "Mercado Pena, Jorge Esteban"]
[Result "1-0"]
[ECO "B76"]
[WhiteElo "1925"]
[BlackElo "1852"]
[PlyCount "53"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 0-0 8. Qd2 Nc6 9. 0-0-0 d5 10. exd5 Nxd5 11. Nxc6 bxc6 12. Bd4 Nxc3 13. Qxc3 Bh6+ 14. Be3 Bxe3+ 15. Qxe3 Qb6 16. Qxe7 Be6 17. Qa3 Rfd8 18. Bd3 Rd5 19. Be4 Ra5 20. Qc3 Rxa2 21. b3 Qa6 22. Kb1 Rb8 23. Rd6 Qa3 24. Rhd1 Kf8 25. Rd8+ Rxd8 26. Qh8+ Ke7 27. Qxd8# 1-0

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.15"]
[Round "4"]
[White "Obando Guzman, Soren Federico"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "A43"]
[WhiteElo "1932"]
[BlackElo "1925"]
[PlyCount "78"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. d4 Nf6 2. Nf3 c5 3. d5 d6 4. Nc3 g6 5. e4 Bg4 6. h3 Bxf3 7. Qxf3 Bg7 8. Be2 Nbd7 9. Bg5 a6 10. a4 h6 11. Be3 Qb6 12. Rb1 Ne5 13. Qg3 Qb4 14. 0-0 Nxe4 15. Qf4 Nf6 16. Qg3 0-0 17. f4 Nc4 18. Bc1 Nb6 19. Bd3 Nxa4 20. Na2 Qd4+ 21. Be3 Qxd5 22. b3 Nb6 23. f5 g5 24. h4 g4 25. Nc3 Qc6 26. Rbe1 Rfe8 27. Bg5 d5 28. Be2 h5 29. Bd3 c4 30. bxc4 Nxc4 31. Qf4 Qd6 32. Qc1 Qa3 33. Bxf6 Qxc1 34. Rxc1 Bxf6 35. Nxd5 Rac8 36. Rfe1 Bxh4 37. Re4 Nd6 38. Rb4 e6 39. fxe6 Rxe6 0-1

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.14"]
[Round "2"]
[White "Pena Escobar, Cristian Camilo"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B79"]
[WhiteElo "1895"]
[BlackElo "1925"]
[PlyCount "58"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 0-0 8. Qd2 Nc6 9. Bc4 Bd7 10. 0-0-0 Ne5 11. Bb3 Qa5 12. Kb1 Rfc8 13. Qf2 Rxc3 14. Bd2 Qc5 15. Bxc3 b5 16. Qe1 Be8 17. h4 Nc4 18. Bxc4 bxc4 19. Ne2 Rb8 20. Bd4 Qb5 21. Qc3 e5 22. Be3 d5 23. Bg5 d4 24. Rxd4 exd4 25. Nxd4 Qb6 26. Re1 Nd5 27. exd5 Bxd4 28. Be3 Bxc3 29. Bxb6 Bxe1 0-1

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.14"]
[Round "3"]
[White "Rosero, Jefferson"]
[Black "Olarte Parra, Jhoan Sebastian"]
[Result "0-1"]
[ECO "B50"]
[WhiteElo "1925"]
[BlackElo "2027"]
[PlyCount "66"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 d6 3. Nf3 e5 4. Bc4 Be6 5. d3 Be7 6. Nd5 Nf6 7. Ng5 Bxd5 8. exd5 Nbd7 9. Qf3 b5 10. Bb3 h6 11. Qh3 Rg8 12. Nf3 g5 13. Qf5 e4 14. Nd2 exd3 15. c4 Ne5 16. 0-0 Qc8 17. Qxc8+ Rxc8 18. a4 b4 19. Re1 Kd8 20. Nf1 a5 21. Ng3 Nfd7 22. Nf5 Bf8 23. f4 gxf4 24. Bxf4 Nf3+ 25. Kf2 Nxe1 26. Rxe1 Rg6 27. Bd1 Ne5 28. Rxe5 dxe5 29. Bxe5 Rg5 30. Bf6+ Kc7 31. Bxg5 hxg5 32. Ke3 Bd6 33. Nxd6 Kxd6 0-1

[Event "COL-ch U18"]
[Site "Bogota"]
[Date "2015.05.13"]
[Round "1"]
[White "Rosero, Jefferson"]
[Black "Salamanca, Juan David"]
[Result "1-0"]
[ECO "C18"]
[WhiteElo "1925"]
[BlackElo "1739"]
[PlyCount "109"]
[EventDate "2015.05.13"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 166 Extra"]
[Source "ChessBase"]
[SourceDate "2015.06.18"]
[SourceVersion "1"]
[SourceVersionDate "2015.06.18"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Bxc3+ 6. bxc3 Nc6 7. Bb5 Nge7 8. a4 Qa5 9. Bxc6+ bxc6 10. Bd2 Ba6 11. Ne2 Bc4 12. Nc1 Qb6 13. a5 Qb5 14. Nb3 Bxb3 15. cxb3 Rb8 16. Ra3 cxd4 17. cxd4 Qd3 18. Qa1 Nf5 19. Qc3 Qe4+ 20. Kd1 Nxd4 21. Re1 Qb1+ 22. Bc1 Rxb3 23. Rxb3 Qxb3+ 24. Qxb3 Nxb3 25. Re3 Nxc1 26. Kxc1 Kd7 27. Rb3 Kc7 28. a6 Rb8 29. Rg3 g6 30. Rf3 f5 31. exf6 Rf8 32. g4 Kb6 33. g5 e5 34. Rh3 Rf7 35. Rh6 Kc5 36. h4 Kd6 37. h5 Ke6 38. hxg6 hxg6 39. Rxg6 d4 40. Rg8 Kf5 41. f3 c5 42. Kd2 c4 43. Kc2 d3+ 44. Kd2 Rc7 45. Rg7 Rc8 46. f7 c3+ 47. Kxd3 c2 48. f8Q+ Rxf8 49. Kxc2 Kf4 50. g6 Kg5 51. Kd3 Rxf3+ 52. Ke4 Rf6 53. Rxa7 Kxg6 54. Kxe5 Rf8 55. Re7 1-0

[Event "Valle Region-ch U18 Integrada"]
[Site "Cali"]
[Date "2015.03.08"]
[Round "6.2"]
[White "Rosero, Jefferson"]
[Black "Pai, Juan David"]
[Result "1-0"]
[ECO "B25"]
[WhiteElo "1868"]
[BlackElo "1612"]
[PlyCount "93"]
[EventDate "2015.03.06"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 d6 3. d3 Nf6 4. g3 g6 5. Bg2 Bg7 6. Nge2 0-0 7. 0-0 Nc6 8. h3 a6 9. Be3 Qc7 10. Qd2 e5 11. Bg5 Be6 12. f4 Nd4 13. f5 Bd7 14. g4 Bc6 15. Bxf6 Bxf6 16. g5 Bg7 17. f6 Bh8 18. Ng3 b5 19. Nd5 Bxd5 20. exd5 b4 21. c3 bxc3 22. bxc3 Nb5 23. a4 Na7 24. c4 Rfc8 25. Be4 Rab8 26. Rab1 a5 27. Kg2 Rb4 28. Qf2 Rcb8 29. Rxb4 Rxb4 30. Nf5 Qb6 31. Ne7+ Kf8 32. Qh4 Rb2+ 33. Kg1 Rb1 34. Qxh7 Rxf1+ 35. Kxf1 Qb1+ 36. Kf2 Qc2+ 37. Kg3 Bxf6 38. gxf6 Ke8 39. Qg8+ Kd7 40. Qxf7 Qd2 41. Nc6+ Kc8 42. Nxa7+ Kb8 43. Nc6+ Kc8 44. Qe8+ Kc7 45. Qd8+ Kb7 46. Qb8+ Ka6 47. Qb5# 1-0

[Event "Valle Region-ch U18 Integrada"]
[Site "Cali"]
[Date "2015.03.08"]
[Round "5.3"]
[White "Zuleta, Juan Carlos"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B77"]
[WhiteElo "1867"]
[BlackElo "1868"]
[PlyCount "80"]
[EventDate "2015.03.06"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 0-0 8. Qd2 Nc6 9. Bc4 Bd7 10. Bb3 Qb8 11. h4 a5 12. 0-0-0 Nxd4 13. Bxd4 a4 14. Bc4 b5 15. Be2 Rc8 16. Bxf6 exf6 17. Qxd6 b4 18. Qxb8 Raxb8 19. Nd5 Kf8 20. Nxb4 Rxb4 21. Rxd7 f5 22. c3 a3 23. Rd8+ Rxd8 24. cxb4 Bxb2+ 25. Kc2 fxe4 26. fxe4 Rd4 27. b5 Rxe4 28. Bd3 Rg4 29. h5 Rxg2+ 30. Kb3 Rg3 31. Kc4 Be5 32. hxg6 hxg6 33. b6 Rg2 34. Kd5 Bh2 35. Bb5 Rxa2 36. b7 Bc7 37. b8Q+ Bxb8 38. Rh8+ Kg7 39. Rxb8 Ra1 40. Kc4 g5 0-1

[Event "Valle Region-ch U18 Integrada"]
[Site "Cali"]
[Date "2015.03.06"]
[Round "1.4"]
[White "Rodriguez Jimenez, Juan Jose"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "A58"]
[WhiteElo "1552"]
[BlackElo "1868"]
[PlyCount "61"]
[EventDate "2015.03.06"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. bxa6 g6 6. Nc3 Bxa6 7. g3 d6 8. Bg2 Nbd7 9. Nh3 Bg7 10. 0-0 Nb6 11. Qc2 c4 12. Be3 0-0 13. Bd4 Bb7 14. Rfd1 Ra6 15. Nf4 Qa8 16. h4 Re8 17. Bxf6 Bxf6 18. Rab1 Be5 19. h5 g5 20. Nh3 h6 21. Qf5 Bc8 22. Qc2 Qa7 23. Nb5 Qd7 24. Nd4 Qg4 25. Ne6 fxe6 26. Qg6+ Kf8 27. Qxh6+ Bg7 28. Qg6 Qf5 29. Qxg5 Qxg5 30. Nxg5 Rxa2 31. dxe6 0-1

[Event "COL-ch U18"]
[Site "Cali"]
[Date "2014.04.05"]
[Round "6"]
[White "Rosero, Jefferson"]
[Black "Zuleta, Juan Carlos"]
[Result "1/2-1/2"]
[ECO "B42"]
[WhiteElo "1746"]
[BlackElo "1860"]
[PlyCount "48"]
[EventDate "2014.04.03"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 159 Extra"]
[Source "ChessBase"]
[SourceDate "2014.04.24"]
[SourceVersion "1"]
[SourceVersionDate "2014.04.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Bd3 Nf6 6. 0-0 d6 7. c4 Be7 8. Nc3 0-0 9. Qe2 Qc7 10. f4 Nbd7 11. Be3 b6 12. Rac1 Bb7 13. Bb1 Rac8 14. b3 Qb8 15. Kh1 Qa8 16. Bg1 Nc5 17. Rfe1 Rfd8 18. e5 Nfd7 19. b4 dxe5 20. fxe5 Nxe5 21. bxc5 Bxc5 22. Nb3 Ba3 23. Rcd1 Rxd1 24. Rxd1 Nxc4 1/2-1/2

[Event "COL-ch U18"]
[Site "Cali"]
[Date "2014.04.05"]
[Round "5"]
[White "Zuleta, Juan Esteban"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "B72"]
[WhiteElo "1803"]
[BlackElo "1746"]
[PlyCount "69"]
[EventDate "2014.04.03"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 159 Extra"]
[Source "ChessBase"]
[SourceDate "2014.04.24"]
[SourceVersion "1"]
[SourceVersionDate "2014.04.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be2 Bg7 7. Be3 Nc6 8. Nb3 0-0 9. Qd2 Bd7 10. 0-0-0 b5 11. Bxb5 Na5 12. Bxd7 Nc4 13. Qd3 Nxe3 14. Qxe3 Nxd7 15. f4 a5 16. e5 a4 17. exd6 exd6 18. Nd4 Nb6 19. Qd3 Qf6 20. g3 d5 21. a3 Rfc8 22. Ndb5 Rc5 23. Rhe1 Nc4 24. Nd4 Qb6 25. b3 Bxd4 26. bxc4 Rxc4 27. Nxd5 Qc5 28. Nb4 Bc3 29. Re4 Rxe4 30. Qxe4 Rc8 31. Kb1 Rb8 32. Ka2 Bg7 33. Qd3 Qe7 34. Qd6 Qe8 35. Re1 1/2-1/2

[Event "COL-ch U18"]
[Site "Cali"]
[Date "2014.04.04"]
[Round "4"]
[White "Olarte Parra, Jhoan Sebastian"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "B50"]
[WhiteElo "1956"]
[BlackElo "1746"]
[PlyCount "41"]
[EventDate "2014.04.03"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 159 Extra"]
[Source "ChessBase"]
[SourceDate "2014.04.24"]
[SourceVersion "1"]
[SourceVersionDate "2014.04.24"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. c4 Bg4 4. Be2 Bxf3 5. Bxf3 Nc6 6. g3 Nf6 7. Nc3 g6 8. d3 Bg7 9. Bg2 0-0 10. f4 Ne8 11. Be3 Nc7 12. 0-0 Ne6 13. f5 Ned4 14. Qd2 b5 15. Bh6 Rb8 16. Bxg7 Kxg7 17. Nd5 f6 18. h4 Qa5 19. Qd1 Ne5 20. Ne3 Qa6 21. Rf2 1/2-1/2

[Event "COL-ch U18"]
[Site "Cali"]
[Date "2014.04.04"]
[Round "3"]
[White "Rosero, Jefferson"]
[Black "Polanco, Brayan Arley"]
[Result "1-0"]
[ECO "E91"]
[WhiteElo "1746"]
[BlackElo "1850"]
[PlyCount "83"]
[EventDate "2014.04.03"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 159 Extra"]
[Source "ChessBase"]
[SourceDate "2014.04.24"]
[SourceVersion "1"]
[SourceVersionDate "2014.04.24"]
[SourceQuality "1"]

1. e4 d6 2. d4 g6 3. c4 Bg7 4. Nc3 Nf6 5. Be2 0-0 6. Nf3 Nbd7 7. 0-0 Nb6 8. h3 c6 9. Qb3 d5 10. cxd5 cxd5 11. e5 Ne4 12. Bf4 Bf5 13. Rac1 Rc8 14. Na4 Nxa4 15. Qxa4 Qb6 16. Qb5 Qxb5 17. Bxb5 h5 18. Ba4 Kh7 19. Bb3 e6 20. Ng5+ Nxg5 21. Bxg5 Bd3 22. Rxc8 Rxc8 23. Rc1 Rxc1+ 24. Bxc1 Bc4 25. f4 Bxb3 26. axb3 Bf8 27. Bd2 Be7 28. g4 hxg4 29. hxg4 Kg7 30. g5 Kf8 31. Kf2 Ke8 32. Ke2 Kd7 33. Kd3 Kc6 34. Bc3 Kb5 35. Kd2 Bb4 36. Kc2 a5 37. Kd2 Bxc3+ 38. bxc3 a4 39. bxa4+ Kxa4 40. c4 Kb4 41. cxd5 Kc4 42. d6 1-0

[Event "COL-ch U18"]
[Site "Cali"]
[Date "2014.04.03"]
[Round "2"]
[White "Salcedo Perez, Pablo Esteban"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "A58"]
[WhiteElo "1950"]
[BlackElo "1746"]
[PlyCount "71"]
[EventDate "2014.04.03"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "CBM 159 Extra"]
[Source "ChessBase"]
[SourceDate "2014.04.24"]
[SourceVersion "1"]
[SourceVersionDate "2014.04.24"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 5. bxa6 Bxa6 6. Nc3 d6 7. Nf3 g6 8. Rb1 Bg7 9. g3 0-0 10. Bg2 Nbd7 11. b3 Qa5 12. Bd2 Rab8 13. a4 c4 14. Nb5 c3 15. Bxc3 Qd8 16. Nfd4 Bxb5 17. Nxb5 Qc8 18. 0-0 Rxb5 19. Bxf6 Bxf6 20. axb5 Qb7 21. b4 Qxb5 22. Qc2 Ne5 23. Rfc1 Ra8 24. h3 Ra7 25. e3 Kg7 26. Qb3 Qe2 27. Bf1 Qh5 28. Qd1 Qf5 29. Rc2 g5 30. Bg2 h5 31. b5 g4 32. hxg4 hxg4 33. b6 Rb7 34. e4 Qh5 35. Rc7 Rb8 36. b7 1-0

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.09"]
[Round "9"]
[White "Alvarez, Juan Evangelista"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "A00"]
[PlyCount "38"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. Nc3 c5 2. d4 cxd4 3. Qxd4 Nc6 4. Qa4 d5 5. Bf4 e6 6. 0-0-0 Nf6 7. Nb5 e5 8. Bxe5 Nxe5 9. Nd6+ Ke7 10. Nxb7 Bxb7 11. Qb4+ Ke8 12. Qxb7 Rb8 13. Qxa7 Nc4 14. b3 Ba3+ 15. Kb1 Ne4 16. Rd3 Ned2+ 17. Rxd2 Nxd2+ 18. Ka1 Qf6+ 19. c3 Qxc3# 0-1

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.08"]
[Round "8"]
[White "Toro Henao, Juan Sebastian"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "A57"]
[WhiteElo "1798"]
[PlyCount "125"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. d4 Nf6 2. c4 c5 3. d5 b5 4. Nd2 Qa5 5. Qc2 Na6 6. e4 d6 7. cxb5 Nc7 8. Qc3 Qb6 9. a4 Qb7 10. f3 a6 11. bxa6 Nxa6 12. Bb5+ Bd7 13. Bxd7+ Nxd7 14. Ne2 Qb4 15. Qc2 Ne5 16. b3 c4 17. bxc4 Nc5 18. 0-0 Ncd3 19. Qc3 Rxa4 20. Rxa4 Qxa4 21. f4 Qa7+ 22. Qd4 Qxd4+ 23. Nxd4 Nd7 24. Ba3 g6 25. Rf3 Nxf4 26. Rxf4 Bh6 27. Rf2 Be3 28. Nc2 Bxf2+ 29. Kxf2 0-0 30. Nd4 Ra8 31. Bb4 Ne5 32. Ke2 Rc8 33. Bc3 Nxc4 34. Nxc4 Rxc4 35. Kd3 Ra4 36. g4 Ra2 37. Nc2 h6 38. h4 Kf8 39. h5 Kg8 40. Ne3 Rh2 41. hxg6 fxg6 42. e5 Rh3 43. exd6 exd6 44. Bb4 h5 45. gxh5 Rxh5 46. Bxd6 Rh7 47. Ke4 Rd7 48. Ke5 Kf7 49. Ng4 Rd8 50. Nf6 Rh8 51. Bc5 Rd8 52. d6 Rc8 53. d7 Rb8 54. Bd6 Ra8 55. Ne4 Ra5+ 56. Bc5 Ra8 57. Ng5+ Kg7 58. d8Q Rxd8 59. Ne6+ Kh6 60. Nxd8 Kg5 61. Nf7+ Kg4 62. Kf6 Kf4 63. Kxg6 1-0

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.07"]
[Round "7"]
[White "Rosero, Jefferson"]
[Black "Cespedes Galindo, Estefania"]
[Result "1-0"]
[ECO "B43"]
[BlackElo "1789"]
[PlyCount "49"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. Nc3 Qc7 6. Be3 Bb4 7. Nde2 Nf6 8. a3 Ba5 9. f3 b5 10. b4 Bb6 11. Bf4 e5 12. Bg5 Qa7 13. Qd6 Bf2+ 14. Kd1 Nc6 15. Bxf6 gxf6 16. Nd5 Rb8 17. c3 a5 18. Rc1 Be3 19. Rc2 axb4 20. cxb4 Qa4 21. Nxe3 Qxa3 22. Nd5 Qd3+ 23. Kc1 Qa3+ 24. Kd2 Rb7 25. Rxc6 1-0

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.07"]
[Round "6"]
[White "Torres, Saulo de Jesus"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B23"]
[WhiteElo "1899"]
[PlyCount "57"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 Nc6 3. Bb5 Nd4 4. Bc4 d6 5. h3 Nf6 6. Nf3 g6 7. d3 Bg7 8. Be3 Nd7 9. Bxd4 cxd4 10. Ne2 Qb6 11. 0-0 Qc5 12. b4 Qxb4 13. Rb1 Qc5 14. Rb5 Qc7 15. Nf4 e6 16. Bxe6 fxe6 17. Nxe6 Qc3 18. Nxg7+ Kf7 19. Nf5 gxf5 20. Rxf5+ Nf6 21. Rf4 Rf8 22. e5 dxe5 23. Nxe5+ Kg7 24. Qf3 Qc7 25. Qg3+ Kh8 26. Rxf6 Qg7 27. Rxf8+ Qxf8 28. Qh4 Bf5 29. Qxd4 1-0

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.06"]
[Round "5"]
[White "Rosero, Jefferson"]
[Black "Rosales, Daniel"]
[Result "0-1"]
[ECO "C16"]
[BlackElo "2062"]
[PlyCount "106"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 Qd7 5. Qg4 f5 6. Qg3 b6 7. a3 Bxc3+ 8. bxc3 Ba6 9. Be2 Bxe2 10. Nxe2 Nc6 11. Qg5 h6 12. Qg6+ Qf7 13. Nf4 Qxg6 14. Nxg6 Rh7 15. h4 Kf7 16. h5 Nge7 17. Nf4 Rhh8 18. a4 Na5 19. Ba3 Nec6 20. g4 fxg4 21. Rg1 Nc4 22. Rxg4 Nxa3 23. Rxa3 Ne7 24. c4 Rhf8 25. Rf3 Nf5 26. c3 c6 27. Rg6 Nh4 28. Rfg3 Nxg6 29. Nxg6 Rfe8 30. Rf3+ Kg8 31. cxd5 cxd5 32. Kd2 Rac8 33. Rg3 Rc7 34. Rg1 Rf7 35. Rg2 Kh7 36. Kd3 Rf3+ 37. Kd2 Rc8 38. Nh4 Rfxc3 39. Rg6 Rc2+ 40. Kd1 Rxf2 41. Rxe6 Rh2 42. Nf3 Rxh5 43. Rd6 Rh3 44. Nd2 Rd3 45. Rxd5 Rc4 46. e6 Rc6 47. Ke2 Rxd2+ 48. Kxd2 Rxe6 49. Kd3 Re7 50. Rb5 g5 51. d5 Kg6 52. d6 Rd7 53. Rd5 Kf6 0-1

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.05"]
[Round "3"]
[White "Navia Alvarez, Edwin Adrian"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B33"]
[WhiteElo "2057"]
[PlyCount "39"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Bg5 a6 8. Na3 b5 9. Bxf6 gxf6 10. Nd5 Bg7 11. c3 f5 12. exf5 Bxf5 13. Nc2 0-0 14. Nce3 Be6 15. g3 f5 16. Bg2 Rc8 17. 0-0 Qg5 18. f4 Qh6 19. a4 bxa4 20. Rxa4 1-0

[Event "Latin Cup-A 3rd"]
[Site "Cali"]
[Date "2012.10.05"]
[Round "2"]
[White "Rosero, Jefferson"]
[Black "Salcedo Perez, Pablo Esteban"]
[Result "1-0"]
[ECO "B90"]
[BlackElo "1788"]
[PlyCount "72"]
[EventDate "2012.10.04"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "CBM 150 Extra"]
[Source "ChessBase"]
[SourceDate "2012.10.19"]
[SourceVersion "1"]
[SourceVersionDate "2012.10.19"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e5 7. Nb3 Be6 8. Be3 Be7 9. g4 Nfd7 10. Qd2 Bh4+ 11. Bf2 Bxf2+ 12. Qxf2 Qf6 13. Rg1 Nc6 14. 0-0-0 Bxb3 15. axb3 Rc8 16. Nd5 Qd8 17. Kb1 Nd4 18. Rxd4 exd4 19. Qxd4 Nf6 20. Ne3 Qa5 21. g5 Nd7 22. Bh3 Qe5 23. Bxd7+ Kxd7 24. Qd3 b5 25. Ng4 Qc5 26. Rd1 Ke7 27. e5 Rhd8 28. Qf5 dxe5 29. Re1 e4 30. Rxe4+ Kd6 31. Qxf7 Qxc2+ 32. Ka2 Kc6 33. Re6+ Kc5 34. Qe7+ Kd4 35. Qxg7+ Kd3 36. Qxh7+ Kd2 1-0

[Event "South Region-ch U18"]
[Site "Cali"]
[Date "2012.04.21"]
[Round "5.4"]
[White "Rosero, Jefferson"]
[Black "Valencia, Jefferson"]
[Result "1-0"]
[ECO "B80"]
[PlyCount "61"]
[EventDate "2012.04.19"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. Nc3 Nf6 4. d4 cxd4 5. Nxd4 a6 6. f3 Qc7 7. Be3 e6 8. Qd2 b5 9. g4 Be7 10. 0-0-0 Nc6 11. Qf2 Rb8 12. g5 Nd7 13. Kb1 Nce5 14. h4 Nb6 15. Rg1 Nbc4 16. Bc1 b4 17. Nce2 Qb6 18. Ka1 a5 19. f4 Nc6 20. Ng3 Ba6 21. Bxc4 Bxc4 22. Be3 Qb7 23. Nxc6 Qxc6 24. Bd4 f6 25. Nh5 Qxe4 26. Nxg7+ Kf7 27. gxf6 Bxf6 28. Bxf6 Kxf6 29. Nh5+ Kf7 30. Rg7+ Kf8 31. Qa7 1-0

[Event "South Region-ch U18"]
[Site "Cali"]
[Date "2012.04.20"]
[Round "2.8"]
[White "Gomez, Luis Miguel"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B33"]
[PlyCount "70"]
[EventDate "2012.04.19"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Bg5 a6 8. Na3 b5 9. Nd5 Be7 10. Bxf6 Bxf6 11. c3 Bg5 12. Be2 Ne7 13. Nc2 f5 14. Bf3 0-0 15. Nxe7+ Qxe7 16. exf5 e4 17. Bg4 Bxf5 18. Qd5+ Qf7 19. Qxf7+ Rxf7 20. Bxf5 Rxf5 21. Nd4 Rf6 22. Ke2 Rb8 23. Nc6 Rb7 24. Rhd1 e3 25. f3 Rh6 26. Rh1 d5 27. Nb4 Rd6 28. Nc2 a5 29. Rad1 Rbd7 30. g3 b4 31. cxb4 d4 32. Rd3 axb4 33. Rhd1 Bf6 34. Nxe3 Re7 35. Kf1 dxe3 0-1

[Event "South Region-ch U18"]
[Site "Cali"]
[Date "2012.04.20"]
[Round "3.5"]
[White "Rosero, Jefferson"]
[Black "Agudelo, Pedro Luis"]
[Result "1/2-1/2"]
[ECO "C78"]
[PlyCount "102"]
[EventDate "2012.04.19"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. 0-0 b5 6. Bb3 Bc5 7. Nxe5 Nxe5 8. d4 Bxd4 9. Qxd4 d6 10. f4 c5 11. Qd1 Nc6 12. Bd5 Bb7 13. Nc3 b4 14. Ne2 Nxd5 15. Qxd5 Qc7 16. Qg5 f6 17. Qh5+ Qf7 18. Qg4 0-0 19. Be3 Rfe8 20. Ng3 Na5 21. Nf5 Qf8 22. e5 Bc8 23. Qh5 Bxf5 24. Qxf5 Nc4 25. Qd3 Nxe3 26. Qxe3 dxe5 27. fxe5 Rxe5 28. Qxe5 fxe5 29. Rxf8+ Kxf8 30. Rd1 Ke7 31. Rd5 Ke6 32. Rxc5 Kd6 33. Rc4 a5 34. Kf2 Ra7 35. Ke3 Rc7 36. Rxc7 Kxc7 37. Ke4 Kd6 38. g4 g6 39. g5 Ke6 40. h4 Kd6 41. c3 bxc3 42. bxc3 a4 43. c4 a3 44. c5+ Kxc5 45. Kxe5 Kc4 46. Kf6 Kc3 47. Kg7 Kb2 48. Kxh7 Kxa2 49. h5 gxh5 50. g6 Kb2 51. g7 a2 1/2-1/2

[Event "South Region-ch U18"]
[Site "Cali"]
[Date "2012.04.19"]
[Round "1.2"]
[White "Rosero, Jefferson"]
[Black "Escobar Barona, Juan Fernando"]
[Result "0-1"]
[ECO "B90"]
[BlackElo "1995"]
[PlyCount "34"]
[EventDate "2012.04.19"]
[EventType "swiss"]
[EventRounds "6"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e5 7. Nb3 Be6 8. Be3 Be7 9. Qd2 Nbd7 10. h4 b5 11. Nd5 Bxd5 12. exd5 Nb6 13. Bxb6 Qxb6 14. Na5 Nxd5 15. Nc4 bxc4 16. Qxd5 Rc8 17. Bxc4 Qb4+ 0-1

[Event "Cartago CupT"]
[Site "Cartago"]
[Date "2011.08.31"]
[Round "3.3"]
[White "Becerra, Manuel Santiago"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "D05"]
[PlyCount "47"]
[EventDate "2011.08.31"]
[EventType "team-swiss"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "CBM 144 Extra"]
[Source "ChessBase"]
[SourceDate "2011.10.28"]
[SourceVersion "1"]
[SourceVersionDate "2011.10.28"]
[SourceQuality "1"]
[WhiteTeam "Buga"]
[BlackTeam "Yumbo"]
[WhiteTeamCountry "COL"]
[BlackTeamCountry "COL"]

1. d4 Nf6 2. e3 c5 3. Bd3 e6 4. Nd2 Nc6 5. Ngf3 d5 6. c3 cxd4 7. exd4 Bd6 8. 0-0 Qc7 9. Qe2 0-0 10. h3 Ne7 11. Ne5 Ng6 12. f4 Bxe5 13. fxe5 Nd7 14. Nf3 Re8 15. Ng5 Re7 16. Qf3 Ndf8 17. Bxg6 hxg6 18. h4 Nh7 19. h5 b6 20. hxg6 fxg6 21. Nxh7 Kxh7 22. Qh3+ Kg8 23. Bg5 Rd7 24. Rf8+ 1-0

[Event "Cartago CupT"]
[Site "Cartago"]
[Date "2011.08.31"]
[Round "5.3"]
[White "Rosero, Jefferson"]
[Black "Cuervo, Andersson"]
[Result "1-0"]
[ECO "B32"]
[PlyCount "43"]
[EventDate "2011.08.31"]
[EventType "team-swiss"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "CBM 144 Extra"]
[Source "ChessBase"]
[SourceDate "2011.10.28"]
[SourceVersion "1"]
[SourceVersionDate "2011.10.28"]
[SourceQuality "1"]
[WhiteTeam "Yumbo"]
[BlackTeam "Roldanillo"]
[WhiteTeamCountry "COL"]
[BlackTeamCountry "COL"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e5 5. Nb5 a6 6. Nd6+ Bxd6 7. Qxd6 Qf6 8. Qxf6 Nxf6 9. Nc3 Nd4 10. Kd1 Ng4 11. Be3 f5 12. exf5 Nxf5 13. Kd2 0-0 14. Bc4+ Kh8 15. h3 Nf6 16. g4 Ne7 17. Bc5 d6 18. Bb4 b5 19. Bd3 a5 20. Bxd6 Rd8 21. Bxe7 Rd7 22. Bxf6 1-0

[Event "Cartago CupT"]
[Site "Cartago"]
[Date "2011.08.31"]
[Round "2.3"]
[White "Rosero, Jefferson"]
[Black "Gonzalez, Andres Felipe"]
[Result "1-0"]
[ECO "B36"]
[BlackElo "1962"]
[PlyCount "81"]
[EventDate "2011.08.31"]
[EventType "team-swiss"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "CBM 144 Extra"]
[Source "ChessBase"]
[SourceDate "2011.10.28"]
[SourceVersion "1"]
[SourceVersionDate "2011.10.28"]
[SourceQuality "1"]
[WhiteTeam "Yumbo"]
[BlackTeam "Palmira"]
[WhiteTeamCountry "COL"]
[BlackTeamCountry "COL"]

1. e4 c5 2. Nf3 g6 3. d4 cxd4 4. Nxd4 Nc6 5. c4 Nf6 6. Nc3 Bg7 7. Be2 Nxd4 8. Qxd4 d6 9. 0-0 0-0 10. Qe3 Be6 11. Rb1 a5 12. b3 Nd7 13. Bd2 Nc5 14. a4 Bd7 15. Bd1 Bc6 16. Bc2 Qd7 17. Nd5 Bxd5 18. exd5 b6 19. f4 Rae8 20. f5 Qc7 21. Rf3 Nd7 22. Qg5 f6 23. Qh4 g5 24. Qh5 Ne5 25. Rg3 Qd7 26. h4 h6 27. Bc3 Rd8 28. Bxe5 dxe5 29. Be4 Qe8 30. Qxe8 Rfxe8 31. h5 Rd6 32. b4 Rc8 33. Rc3 axb4 34. Rxb4 Bf8 35. Rcb3 e6 36. fxe6 Rdd8 37. Rxb6 Bc5+ 38. Kh2 Bxb6 39. Rxb6 Rxc4 40. Bg6 Rxd5 41. Rb8+ 1-0

[Event "Cartago CupT"]
[Site "Cartago"]
[Date "2011.08.31"]
[Round "1.3"]
[White "Rosero, Jefferson"]
[Black "Minotta, Rosney"]
[Result "1-0"]
[ECO "C60"]
[PlyCount "37"]
[EventDate "2011.08.31"]
[EventType "team-swiss"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "CBM 144 Extra"]
[Source "ChessBase"]
[SourceDate "2011.10.28"]
[SourceVersion "1"]
[SourceVersionDate "2011.10.28"]
[SourceQuality "1"]
[WhiteTeam "Yumbo"]
[BlackTeam "Buenaventura II"]
[WhiteTeamCountry "COL"]
[BlackTeamCountry "COL"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Bb4 4. c3 Bc5 5. 0-0 Nf6 6. d4 exd4 7. cxd4 Nxd4 8. Nxd4 a6 9. Be2 d6 10. Nc3 Bg4 11. Bxg4 Nxg4 12. Qxg4 Bxd4 13. Be3 c6 14. Bxd4 c5 15. Be3 f6 16. Nd5 b5 17. Qxg7 Rf8 18. Nc7+ Qxc7 19. Qxc7 1-0

[Event "Cartago CupT"]
[Site "Cartago"]
[Date "2011.08.31"]
[Round "4.3"]
[White "Villamil, Nahum Jose"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B33"]
[WhiteElo "1839"]
[PlyCount "53"]
[EventDate "2011.08.31"]
[EventType "team-swiss"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "CBM 144 Extra"]
[Source "ChessBase"]
[SourceDate "2011.10.28"]
[SourceVersion "1"]
[SourceVersionDate "2011.10.28"]
[SourceQuality "1"]
[WhiteTeam "Cartago"]
[BlackTeam "Yumbo"]
[WhiteTeamCountry "COL"]
[BlackTeamCountry "COL"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Bg5 a6 8. Na3 b5 9. Bxf6 gxf6 10. Nd5 Bg7 11. Bd3 Ne7 12. Nxe7 Qxe7 13. Qh5 f5 14. 0-0 d5 15. exd5 e4 16. c3 0-0 17. Rfe1 b4 18. Nc4 bxc3 19. d6 Qf6 20. Rxe4 fxe4 21. Bxe4 h6 22. Bxa8 Bf5 23. Bd5 cxb2 24. Nxb2 Qxb2 25. Re1 Qd2 26. Qd1 Qxd1 27. Rxd1 0-1

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "6"]
[White "Arias Monsalve, Andres Felipe"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B26"]
[PlyCount "48"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 Nc6 3. g3 g6 4. d3 Bg7 5. Bg2 e6 6. Nge2 Nge7 7. Be3 d6 8. Qd2 Nd4 9. f4 Qa5 10. 0-0 Nec6 11. a3 Rb8 12. Rae1 0-0 13. Nc1 b5 14. e5 b4 15. Bxd4 Nxd4 16. N3e2 dxe5 17. axb4 cxb4 18. fxe5 Qxe5 19. c3 bxc3 20. bxc3 Nf5 21. Qa2 Bb7 22. Qxa7 Bxg2 23. Nf4 Qxc3 24. Nxg2 Bd4+ 0-1

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "2"]
[White "De la Cerda, Damian Josue"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B22"]
[PlyCount "50"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. c3 d5 4. exd5 Qxd5 5. d4 Bg4 6. Be3 Bxf3 7. Qxf3 Qxf3 8. gxf3 cxd4 9. cxd4 0-0-0 10. Bc4 e6 11. 0-0 Nxd4 12. Bxd4 Rxd4 13. Rc1 Kb8 14. b3 g6 15. a4 Bh6 16. Re1 Nf6 17. Na3 Rhd8 18. Nc2 Rh4 19. Kg2 Bf4 20. h3 Rd2 21. Ne3 Bxe3 22. Rxe3 Rb2 23. Rc3 a6 24. a5 Rd4 25. Rac1 Rd8 0-1

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "9"]
[White "Echavarria Ramirez, Juan Diego"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "A30"]
[PlyCount "42"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. d4 c5 2. Nf3 e6 3. c4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6 6. e3 Be7 7. Be2 0-0 8. 0-0 b6 9. b3 Bb7 10. Bb2 Rc8 11. Rc1 Bd6 12. Bf3 Bb8 13. Qe2 e5 14. Nf5 Re8 15. Ng3 a6 16. Rfd1 Qc7 17. Nd5 Nxd5 18. cxd5 e4 19. Bg4 Nd4 20. exd4 Qd6 21. Qe3 g6 1-0

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "5"]
[White "Gomez, Luis Miguel"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B33"]
[PlyCount "31"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Nd5 Nxd5 8. exd5 Nb8 9. c4 Be7 10. Be3 0-0 11. Bd3 a6 12. Nc3 f5 13. 0-0 Nd7 14. f3 Nc5 15. Be2 a5 16. b3 0-1

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "1"]
[White "Gonzalez, Andres Felipe"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B30"]
[WhiteElo "1962"]
[PlyCount "67"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. Bb5 e6 4. 0-0 Nge7 5. d3 a6 6. Ba4 b5 7. Bb3 Ng6 8. Re1 d6 9. a4 Bb7 10. Na3 Na7 11. Bg5 Be7 12. Bxe7 Qxe7 13. c3 0-0 14. axb5 axb5 15. d4 Rfd8 16. d5 Qd7 17. c4 b4 18. Nb5 Nxb5 19. cxb5 e5 20. Bc4 Ne7 21. Rxa8 Rxa8 22. b3 Nc8 23. Nh4 g6 24. h3 Ra5 25. Qd3 Na7 26. Nf3 Nxb5 27. Bxb5 Qxb5 28. Qxb5 Rxb5 29. Nd2 Kf8 30. Nc4 Ke7 31. Ra1 Bc8 32. Ra8 Kd7 33. Rxc8 Rb7 34. Ra8 1-0

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "8"]
[White "Rosero, Jefferson"]
[Black "Agudelo, Pedro Luis"]
[Result "1-0"]
[ECO "C89"]
[PlyCount "47"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. 0-0 Be7 6. Re1 0-0 7. c3 b5 8. Bb3 Bb7 9. d4 exd4 10. cxd4 d6 11. Bf4 Qd7 12. Nbd2 Nb4 13. Qe2 Qg4 14. Bg3 Nh5 15. a3 Nc6 16. Rac1 Rac8 17. Qd3 Nxg3 18. hxg3 Bg5 19. Nxg5 Qxg5 20. f4 Qf6 21. Nf3 Na5 22. Bc2 Nc4 23. e5 Qg6 24. Qxc4 1-0

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "7"]
[White "Rosero, Jefferson"]
[Black "Bocanegra Acosta, Erick"]
[Result "0-1"]
[ECO "B38"]
[PlyCount "55"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. c4 Bg7 6. Be3 Nf6 7. Nc3 0-0 8. Be2 d6 9. 0-0 Bd7 10. f4 Nxd4 11. Bxd4 Bc6 12. Bf3 a5 13. Nd5 Nd7 14. Bxg7 Kxg7 15. Qd4+ Kg8 16. Rad1 Bxd5 17. Qxd5 Qb6+ 18. Kh1 Nc5 19. Qd2 Qb4 20. Qe2 Na4 21. Rd2 Rac8 22. a3 Qb6 23. f5 Nc5 24. e5 Nb3 25. Rd5 Qc7 26. exd6 exd6 27. Rd3 Qxc4 28. Bd5 0-1

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "3"]
[White "Rosero, Jefferson"]
[Black "Castro, Jairo Antonio"]
[Result "0-1"]
[ECO "B76"]
[BlackElo "1896"]
[PlyCount "76"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. f3 Bg7 7. Be3 Nc6 8. Qd2 0-0 9. 0-0-0 Nxd4 10. Bxd4 Be6 11. g4 Qa5 12. Kb1 Rfc8 13. Nd5 Qxd2 14. Nxf6+ Bxf6 15. Rxd2 Bxd4 16. Rxd4 Rc5 17. h4 Rac8 18. c3 a5 19. Rg1 b5 20. f4 b4 21. f5 Bc4 22. cxb4 axb4 23. Bxc4 Rxc4 24. Rgd1 Kf8 25. b3 Rxd4 26. Rxd4 Rb8 27. Rc4 Ke8 28. Rc7 Kd8 29. Ra7 Rb5 30. f6 Re5 31. Rxe7 Rxe7 32. fxe7+ Kxe7 33. Kc2 Ke6 34. Kd3 d5 35. Kd4 dxe4 36. Kxe4 f5+ 37. gxf5+ gxf5+ 38. Kf4 Kf6 0-1

[Event "Pan American-ch U14"]
[Site "Cali"]
[Date "2011.07.??"]
[Round "4"]
[White "Rosero, Jefferson"]
[Black "Londono Lopez, David"]
[Result "0-1"]
[ECO "B45"]
[PlyCount "30"]
[EventDate "2011.07.03"]
[EventType "swiss"]
[EventRounds "9"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 e6 5. Nc3 Nf6 6. Bc4 Bb4 7. Bg5 h6 8. Bxf6 Qxf6 9. Nde2 a6 10. a4 0-0 11. 0-0 Qg6 12. f4 f5 13. exf5 Qxf5 14. Ng3 Qc5+ 15. Kh1 Qxc4 0-1

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "4.1"]
[White "Arce, Jhonatan"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "B33"]
[WhiteElo "1793"]
[PlyCount "80"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Nb3 Bb4 7. f3 d5 8. exd5 Nxd5 9. Bd2 Nxc3 10. bxc3 Be7 11. Bd3 0-0 12. 0-0 Bg5 13. Qe2 Re8 14. Rad1 Qf6 15. Qe4 g6 16. f4 Bh6 17. fxe5 Qg7 18. Bxh6 Qxh6 19. Bc4 Be6 20. Bxe6 Rxe6 21. Rd7 f5 22. Qc4 Qe3+ 23. Kh1 Rae8 24. Rxb7 Nxe5 25. Qd4 Qxd4 26. cxd4 Ng4 27. h3 Re1 28. Kg1 Rxf1+ 29. Kxf1 Ne3+ 30. Kf2 Nxc2 31. Rxa7 Rd8 32. Ra4 Kf7 33. Ke2 f4 34. Kd2 Ne3 35. Ke2 Re8 36. Kf3 g5 37. Ra5 Kg6 38. Nd2 Nxg2 39. Kxg2 Re2+ 40. Kf3 Rxd2 1/2-1/2

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "2.1"]
[White "Hernandez, Cristian Andres"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B33"]
[WhiteElo "1995"]
[PlyCount "53"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Nd5 Nxd5 8. exd5 Nb8 9. c4 Be7 10. Be2 Bf5 11. 0-0 a6 12. Nc3 0-0 13. f4 exf4 14. Bxf4 Bg6 15. Kh1 Nd7 16. Bd3 Bxd3 17. Qxd3 Nc5 18. Qc2 Rc8 19. Rae1 Re8 20. Re3 Nd7 21. Rfe1 Nf6 22. Qd3 Qd7 23. h3 Nh5 24. Bh2 Nf6 25. b3 Bd8 26. Rxe8+ Nxe8 27. Qf5 1-0

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "7.1"]
[White "Rosero, Jefferson"]
[Black "Parra Meza, Brayan"]
[Result "1/2-1/2"]
[ECO "C96"]
[BlackElo "1816"]
[PlyCount "37"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5 5. Bb3 Nf6 6. 0-0 Be7 7. Re1 d6 8. c3 0-0 9. h3 Na5 10. Bc2 c5 11. a4 Be6 12. d3 Re8 13. Nbd2 g6 14. Nf1 Bf8 15. b4 Nc6 16. Bb3 Bxb3 17. Qxb3 Qc7 18. Bd2 Reb8 19. a5 1/2-1/2

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "3.1"]
[White "Rosero, Jefferson"]
[Black "Ramos Ariza, Juan Manuel"]
[Result "1/2-1/2"]
[ECO "B80"]
[PlyCount "60"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e6 7. Be3 Qc7 8. Qd2 b5 9. h4 Bb7 10. h5 Nc6 11. g4 Rc8 12. g5 Nd7 13. Rh2 Nde5 14. Qf2 b4 15. Na4 Nxd4 16. Bxd4 d5 17. exd5 Nxf3+ 18. Qxf3 Qxh2 19. Nb6 Rd8 20. h6 Qh4+ 21. Qf2 Qe4+ 22. Be2 e5 23. 0-0-0 Be7 24. Bf3 Qf5 25. Be3 0-0 26. Qg2 Bc8 27. Rh1 g6 28. Rh4 Bxg5 29. Bxg5 f6 30. Bd2 Bd7 1/2-1/2

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "1.1"]
[White "Rosero, Jefferson"]
[Black "Sanchez, Brayan Camilo"]
[Result "1-0"]
[ECO "B18"]
[PlyCount "77"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. Nf3 Nd7 7. Bd3 Bxd3 8. Qxd3 Ngf6 9. 0-0 e6 10. Re1 Bd6 11. Ne5 Qc7 12. f4 0-0 13. Nh1 c5 14. Be3 cxd4 15. Bxd4 Bc5 16. Bxc5 Qxc5+ 17. Nf2 Rfd8 18. Qh3 Qxc2 19. Nfd3 Nxe5 20. Nxe5 Ne4 21. Qf3 Qc5+ 22. Qe3 Qxe3+ 23. Rxe3 Nf6 24. Rc3 Rac8 25. Ra3 a6 26. Rb3 Rc7 27. a4 Rd2 28. Rc3 Rxc3 29. bxc3 Nd5 30. Rb1 Nxf4 31. Rxb7 h6 32. Rxf7 Nd5 33. Ra7 Nxc3 34. Rxa6 Ne4 35. h4 Ra2 36. h5 Nc3 37. Ra8+ Kh7 38. Ng6 Rxa4 39. Rh8# 1-0

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "5.1"]
[White "Rosero, Jefferson"]
[Black "Sierra, Juan Daniel1"]
[Result "1-0"]
[ECO "C75"]
[PlyCount "71"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. d4 Bd7 5. c3 a6 6. Ba4 b5 7. Bc2 Nf6 8. Nbd2 Bg4 9. d5 Ne7 10. Nf1 Ng6 11. h3 Bxf3 12. Qxf3 Nh4 13. Qg3 Nh5 14. Qg4 g6 15. Ne3 Ng7 16. g3 f5 17. Qe2 f4 18. Nd1 f3 19. Qd3 Ng2+ 20. Kf1 Qf6 21. a4 Be7 22. axb5 0-0 23. bxa6 Nh5 24. Ne3 g5 25. Nf5 Ng7 26. Qxf3 h5 27. Kxg2 Nxf5 28. exf5 h4 29. g4 Qf7 30. a7 Bf6 31. Be3 Rfc8 32. Ba4 c5 33. dxc6 Rc7 34. Bb6 Raxa7 35. Bxa7 Rxa7 36. Qe3 1-0

[Event "South Region-ch U16"]
[Site "Cali"]
[Date "2011.04.05"]
[Round "6.1"]
[White "Villamil, Nahum Jose"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B33"]
[WhiteElo "1848"]
[PlyCount "57"]
[EventDate "2011.04.05"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Bg5 a6 8. Na3 b5 9. Nd5 Be7 10. Bxf6 Bxf6 11. c4 Nd4 12. cxb5 0-0 13. Nc2 axb5 14. Nxf6+ Qxf6 15. Nxd4 exd4 16. Bxb5 Be6 17. 0-0 Bxa2 18. b3 d3 19. Qxd3 Rfc8 20. Ba6 Rc3 21. Qd5 Rxa6 22. Qb7 Rac6 23. Rxa2 g6 24. Ra8+ Kg7 25. Qb8 Qf4 26. Qf8+ Kf6 27. Ra7 Kg5 28. Rxf7 Qd2 29. Rxh7 1-0

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.18"]
[Round "7.1"]
[White "Parra Meza, Brayan"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B33"]
[WhiteElo "1826"]
[BlackElo "1632"]
[PlyCount "51"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. a4 a6 8. Na3 Be6 9. Bc4 Be7 10. 0-0 Qd7 11. Bg5 Ng4 12. Bxe7 Nxe7 13. Bxe6 Qxe6 14. Qe2 Rc8 15. Rfd1 Nf6 16. Rd3 Ng6 17. Qd2 Rc6 18. Rd1 Kd7 19. f3 h5 20. Nd5 h4 21. Rb3 Kc8 22. Qb4 Rc5 23. Qxb7+ Kd8 24. Qb6+ Kc8 25. Qb8+ Kd7 26. Rb7+ 1-0

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.17"]
[Round "3.1"]
[White "Barba, Deina Alexandra"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B25"]
[WhiteElo "1705"]
[BlackElo "1632"]
[PlyCount "54"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nc3 Nc6 3. Nge2 e5 4. g3 g6 5. Bg2 Bg7 6. d3 Nge7 7. Be3 d6 8. 0-0 0-0 9. Qd2 f5 10. f4 Nd4 11. fxe5 dxe5 12. Bg5 Qd6 13. Bxe7 Qxe7 14. Nd5 Nxe2+ 15. Qxe2 Qg5 16. b4 cxb4 17. Nxb4 f4 18. Qf2 h5 19. Kh1 Be6 20. Rab1 Rf7 21. Nd5 Raf8 22. c4 f3 23. h4 fxg2+ 24. Qxg2 Rxf1+ 25. Rxf1 Rxf1+ 26. Qxf1 Qxg3 27. Ne7+ Kh7 0-1

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.17"]
[Round "5.1"]
[White "Gonzalez, Andres Felipe"]
[Black "Rosero, Jefferson"]
[Result "1/2-1/2"]
[ECO "B33"]
[WhiteElo "1671"]
[BlackElo "1632"]
[PlyCount "97"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Nb3 Bb4 7. Bd2 Bxc3 8. Bxc3 Nxe4 9. Qg4 Ng5 10. h4 Ne6 11. 0-0-0 d5 12. Qg3 0-0 13. Bxe5 Nxe5 14. Qxe5 Nc7 15. Bd3 Re8 16. Qg5 Qxg5+ 17. hxg5 g6 18. Rh2 Ne6 19. Rdh1 Nf8 20. Nd4 Bd7 21. f4 Re3 22. f5 Rae8 23. Kd2 Rg3 24. fxg6 fxg6 25. Nf3 Bg4 26. Rf1 Bxf3 27. gxf3 Rxg5 28. f4 Rg3 29. f5 Ree3 30. fxg6 hxg6 31. Rhf2 Re8 32. Rf7 Rg2+ 33. Kc3 Ne6 34. Rxb7 Rc8+ 35. Kb4 a6 36. Rb6 Rg4+ 37. Ka3 Nd4 38. Rxg6+ Rxg6 39. Bxg6 Nxc2+ 40. Bxc2 Rxc2 41. Rd1 Rc5 42. b4 Rb5 43. Kb3 a5 44. Ka4 Rxb4+ 45. Kxa5 Rb2 46. a4 Kf7 47. Rxd5 Ke6 48. Rd1 Rb1 49. Re1+ 1/2-1/2

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.17"]
[Round "6.1"]
[White "Rosero, Jefferson"]
[Black "Norena, Wilder"]
[Result "1-0"]
[ECO "C96"]
[WhiteElo "1632"]
[BlackElo "1604"]
[PlyCount "115"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5 5. Bb3 Nf6 6. 0-0 Be7 7. Re1 d6 8. h3 0-0 9. c3 Na5 10. Bc2 c5 11. a4 Bd7 12. d3 Qc7 13. Nbd2 Rfc8 14. Nf1 Bf8 15. Bg5 Qd8 16. Ne3 g6 17. Nd5 Bg7 18. Nh2 Be6 19. Ng4 Bxd5 20. exd5 h6 21. Nxf6+ Bxf6 22. Bxh6 Bg5 23. Bxg5 Qxg5 24. Re3 Kg7 25. Rg3 Qf6 26. Qf3 Qxf3 27. Rxf3 c4 28. axb5 axb5 29. d4 f5 30. dxe5 dxe5 31. Re3 Kf6 32. g3 Nb3 33. Rae1 Re8 34. f4 e4 35. g4 Nd2 36. Rd1 Nf3+ 37. Kg2 Ra2 38. g5+ Kf7 39. Re2 Rxb2 40. Kg3 Ke7 41. h4 Rh8 42. Rh1 Kd6 43. h5 gxh5 44. g6 Rg8 45. Rxh5 Rxg6+ 46. Kf2 Rf6 47. Rh8 Kxd5 48. Bxe4+ fxe4 49. Rxb2 Rxf4 50. Ke3 Ne1 51. Rxb5+ Kc6 52. Rb4 Rf3+ 53. Kxe4 Rxc3 54. Rc8+ Kd7 55. Kf4 Rf3+ 56. Ke5 Rg3 57. Rbxc4 Rh3 58. R4c7# 1-0

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.17"]
[Round "4.2"]
[White "Rosero, Jefferson"]
[Black "Tamayo, Michael Leandro"]
[Result "1-0"]
[ECO "C75"]
[WhiteElo "1632"]
[BlackElo "1613"]
[PlyCount "73"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. h3 Bd7 6. c3 Nf6 7. Bc2 Be7 8. 0-0 0-0 9. d4 Re8 10. Be3 exd4 11. cxd4 h6 12. Nc3 Bf8 13. Qd2 Qc8 14. Nh2 Na5 15. b3 Nc6 16. f4 Qd8 17. g4 Nh7 18. Qf2 Be7 19. Nf3 Rf8 20. Qg3 g5 21. f5 f6 22. Bd3 Be8 23. Rf2 Bf7 24. h4 Kg7 25. hxg5 Nxg5 26. Raf1 Rh8 27. Bc4 Nb4 28. Bxf7 Kxf7 29. e5 dxe5 30. dxe5 Nd3 31. e6+ Kg7 32. Rd2 Nxf3+ 33. Rxf3 Bd6 34. Rxd3 Bxg3 35. Rxd8 Raxd8 36. Rxg3 Rd3 37. Bxh6+ 1-0

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.16"]
[Round "2.1"]
[White "Rosero, Jefferson"]
[Black "Dominguez, Laura Lucia"]
[Result "1-0"]
[ECO "C23"]
[WhiteElo "1632"]
[BlackElo "1970"]
[PlyCount "7"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Bc4 Bc5 3. Qh5 Bf8 4. Qxf7# 1-0

[Event "Colombia Mire Lea Florida Cup U15"]
[Site "Colombia"]
[Date "2010.10.16"]
[Round "1.8"]
[White "Vergara Quintero, Santiago"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "A00"]
[WhiteElo "1500"]
[BlackElo "1632"]
[PlyCount "10"]
[EventDate "2010.10.16"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. a3 Nf6 2. h3 e5 3. a4 Bc5 4. h4 Ng4 5. h5 Bxf2# 0-1

[Event "Buga School A"]
[Site "Buga"]
[Date "2010.07.24"]
[Round "3.4"]
[White "Rosero, Jefferson"]
[Black "Gomez Fierro, Joan Naren"]
[Result "1-0"]
[ECO "C07"]
[WhiteElo "1584"]
[BlackElo "1603"]
[PlyCount "57"]
[EventDate "2010.07.23"]
[EventType "swiss (rapid)"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e6 2. d4 d5 3. Nd2 c5 4. Ngf3 Nc6 5. Bb5 Qb6 6. Bxc6+ Qxc6 7. Qe2 Be7 8. Ne5 Qb6 9. dxc5 Qxc5 10. Nb3 Qc7 11. Bf4 Qd8 12. Rd1 Nf6 13. Qb5+ Bd7 14. Nxd7 Nxd7 15. exd5 exd5 16. Rxd5 b6 17. 0-0 Rc8 18. Rfd1 a6 19. Qd3 0-0 20. Rxd7 Qe8 21. Re1 Rd8 22. Rexe7 Qxe7 23. Rxe7 Rxd3 24. cxd3 h6 25. Bc7 b5 26. d4 f5 27. Be5 Rf7 28. Rxf7 Kxf7 29. d5 1-0

[Event "Buga School A"]
[Site "Buga"]
[Date "2010.07.24"]
[Round "5.3"]
[White "Rosero, Jefferson"]
[Black "Lozano Betancurt, Juan Sebastian"]
[Result "1-0"]
[ECO "B01"]
[WhiteElo "1584"]
[BlackElo "1400"]
[PlyCount "83"]
[EventDate "2010.07.23"]
[EventType "swiss (rapid)"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 d5 2. exd5 Qxd5 3. Nc3 Qe6+ 4. Be2 Nf6 5. Nf3 g6 6. d4 Bg7 7. 0-0 0-0 8. Bf4 c6 9. Re1 Qd7 10. Ne5 Qf5 11. Qd2 Nd5 12. Nxd5 cxd5 13. Bg4 Qf6 14. Bg5 Qb6 15. Bxe7 Re8 16. Bc5 Qb5 17. a4 Qa6 18. Bxc8 Rxc8 19. Qe2 Qxe2 20. Rxe2 Bxe5 21. Rxe5 Nc6 22. Rxd5 Rd8 23. Rxd8+ Rxd8 24. c3 b6 25. Ba3 Re8 26. Kf1 Na5 27. Re1 Rxe1+ 28. Kxe1 Nc4 29. Ke2 Nxa3 30. bxa3 Kf8 31. Kd3 Ke7 32. Kc4 Kd7 33. Kb5 Kc7 34. Ka6 Kb8 35. d5 Kc7 36. Kxa7 Kd6 37. c4 Kc5 38. Kb7 Kxc4 39. d6 Kb3 40. Kxb6 Kxa3 41. Kb5 Kb3 42. d7 1-0

[Event "Buga School A"]
[Site "Buga"]
[Date "2010.07.24"]
[Round "4.3"]
[White "Torres, Miguel Angel"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B21"]
[WhiteElo "1301"]
[BlackElo "1584"]
[PlyCount "76"]
[EventDate "2010.07.23"]
[EventType "swiss (rapid)"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. f4 Nc6 3. Bb5 Nd4 4. Bc4 e6 5. c3 Nc6 6. Nf3 Na5 7. Bb5 a6 8. Ba4 b5 9. b4 Nc6 10. Bc2 cxb4 11. cxb4 Bxb4 12. 0-0 Nge7 13. a3 Bc5+ 14. d4 Nxd4 15. Nxd4 Qb6 16. Be3 Nc6 17. Nxc6 Bxe3+ 18. Kh1 Qxc6 19. Rf3 Ba7 20. Nc3 Bb7 21. Qd3 Rc8 22. Rd1 h5 23. Rh3 f6 24. g4 Ke7 25. gxh5 f5 26. Rd2 Bb8 27. Rf2 Ba7 28. Rg3 Rh7 29. Rff3 fxe4 30. Qxe4 Qxc3 31. Rxc3 Bxe4+ 32. Rcf3 Rxc2 33. h3 Rf2 34. h6 Bxf3+ 35. Rxf3 Rxf3 36. hxg7 Rhxh3+ 37. Kg2 Rhg3+ 38. Kh2 Bg1+ 0-1

[Event "Buga School A"]
[Site "Buga"]
[Date "2010.07.23"]
[Round "2.4"]
[White "Espitia, Marlon Brandon"]
[Black "Rosero, Jefferson"]
[Result "0-1"]
[ECO "B30"]
[WhiteElo "1500"]
[BlackElo "1584"]
[PlyCount "70"]
[EventDate "2010.07.23"]
[EventType "swiss (rapid)"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. d3 Nc6 3. Nf3 e5 4. Nc3 d6 5. h3 Be6 6. Be3 Be7 7. Be2 Nf6 8. a3 a6 9. Qd2 b5 10. Bg5 Qd7 11. Bxf6 Bxf6 12. a4 b4 13. Na2 Na5 14. b3 d5 15. exd5 Bxd5 16. Qe3 Qd6 17. Rd1 0-0 18. h4 Rfe8 19. h5 Qc6 20. h6 g6 21. c4 Be6 22. Nc1 Bd7 23. Nh4 e4 24. Qg3 Re7 25. 0-0 Rae8 26. dxe4 Rxe4 27. Bf3 Bxh4 28. Bxe4 Qxe4 29. Qc7 Bc6 30. f3 Qe3+ 31. Kh1 Bf2 32. Rxf2 Qxf2 33. Rd8 Qh4+ 34. Kg1 Rxd8 35. Qe5 Rd1+ 0-1

[Event "Buga School A"]
[Site "Buga"]
[Date "2010.07.23"]
[Round "1.2"]
[White "Rosero, Jefferson"]
[Black "Zuleta, Juan Esteban"]
[Result "0-1"]
[ECO "B80"]
[WhiteElo "1584"]
[BlackElo "1916"]
[PlyCount "60"]
[EventDate "2010.07.23"]
[EventType "swiss (rapid)"]
[EventRounds "5"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f3 e6 7. Be3 Be7 8. Qd2 Nc6 9. g4 Qc7 10. h4 b5 11. Bd3 Bb7 12. Qf2 Ne5 13. 0-0-0 Rc8 14. Kb1 Nc4 15. Bxc4 bxc4 16. Rhe1 0-0 17. h5 d5 18. exd5 Nxd5 19. Nxd5 Bxd5 20. g5 c3 21. b3 a5 22. a4 Rb8 23. Nb5 Rxb5 24. axb5 Rc8 25. b6 Qc6 26. g6 a4 27. gxh7+ Kh8 28. Rg1 axb3 29. Rd4 b2 30. Qg2 Bf6 0-1

[Event "COL-ch School U13"]
[Site "Yumbo"]
[Date "2010.04.30"]
[Round "7.13"]
[White "Hurtado, Wilson David"]
[Black "Rosero, Jefferson"]
[Result "1-0"]
[ECO "B33"]
[WhiteElo "1807"]
[BlackElo "1516"]
[PlyCount "117"]
[EventDate "2010.04.27"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Bg5 a6 8. Bxf6 gxf6 9. Na3 Bg7 10. Nd5 b5 11. c3 f5 12. Bd3 Be6 13. Nc2 f4 14. 0-0 Ne7 15. Nxe7 Qxe7 16. a4 bxa4 17. Rxa4 0-0 18. Rxa6 Rxa6 19. Bxa6 Qg5 20. f3 Bh3 21. Rf2 Re8 22. Nb4 Re6 23. Bc8 Rh6 24. Bxh3 Rxh3 25. Qxd6 Bf8 26. Qb8 Kg7 27. Nd3 Rh5 28. b4 Qh4 29. h3 Qe7 30. Qc8 Qd6 31. Qc4 Rg5 32. Qd5 Qf6 33. c4 Qa6 34. h4 Rh5 35. Nxf4 Rxh4 36. Qxe5+ f6 37. Qc7+ Kg8 38. g3 Qa1+ 39. Rf1 Rh1+ 40. Kxh1 Qxf1+ 41. Kh2 Qf2+ 42. Ng2 Qxf3 43. Qf4 Qxf4 44. Nxf4 Bxb4 45. Nd5 Bd6 46. Nxf6+ Kh8 47. Kg2 Be5 48. Nd7 Bc7 49. e5 Kg7 50. e6 Bd6 51. c5 Bc7 52. g4 h6 53. Kf3 Kg6 54. Ke4 Bd8 55. Kd5 Kg5 56. Ne5 Kf6 57. Nf7 Be7 58. c6 h5 59. gxh5 1-0

[Event "COL-ch School U13"]
[Site "Yumbo"]
[Date "2010.04.29"]
[Round "6.10"]
[White "Rosero, Jefferson"]
[Black "Belalcazar, Mateo"]
[Result "1/2-1/2"]
[ECO "C92"]
[WhiteElo "1516"]
[BlackElo "1671"]
[PlyCount "133"]
[EventDate "2010.04.27"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5 5. Bb3 Nf6 6. 0-0 Be7 7. Re1 0-0 8. c3 d6 9. h3 Be6 10. Bc2 d5 11. exd5 Qxd5 12. d3 Nd7 13. Bb3 Qd6 14. Bxe6 Qxe6 15. Nbd2 f5 16. d4 e4 17. Nh2 Qd5 18. Ndf1 Nb6 19. Qh5 Qf7 20. Qxf7+ Rxf7 21. Bf4 Bd6 22. Bxd6 cxd6 23. b3 Nd5 24. Rac1 Nce7 25. c4 Nb4 26. Re2 Nd3 27. Rd1 bxc4 28. bxc4 Nc6 29. d5 Nce5 30. Rc2 Rb8 31. Nd2 Rb2 32. Rxb2 Nxb2 33. Rc1 Rc7 34. c5 Nbd3 35. Rc3 Rxc5 36. Ra3 Rc1+ 37. Nhf1 Nb4 38. Ra4 Ned3 39. a3 Nxd5 40. Rxa6 Nc3 41. Rxd6 Ne2+ 42. Kh2 Nxf2 43. g3 Rc3 44. Kg2 Nd1 45. Nxe4 fxe4 46. Rxd1 Rxa3 47. Kf2 Ra2 48. Rd8+ Kf7 49. Rd7+ Kf6 50. Nd2 Nc3 51. Ke3 Ra4 52. Rd4 Nd1+ 53. Kxe4 Nf2+ 54. Ke3 Rxd4 55. Kxd4 Nxh3 56. Ke4 Kg5 57. Kf3 Ng1+ 58. Kf2 Nh3+ 59. Kf3 Kf5 60. g4+ Kg5 61. Ne4+ Kh4 62. Nd6 Ng1+ 63. Kf4 Ne2+ 64. Ke3 Kxg4 65. Kxe2 h5 66. Ne8 g6 67. Kf2 1/2-1/2

[Event "COL-ch School U13"]
[Site "Yumbo"]
[Date "2010.04.29"]
[Round "5.12"]
[White "Rosero, Jefferson"]
[Black "Ospina, Juan David"]
[Result "1-0"]
[ECO "B38"]
[WhiteElo "1516"]
[BlackElo "1484"]
[PlyCount "69"]
[EventDate "2010.04.27"]
[EventType "swiss"]
[EventRounds "7"]
[EventCountry "COL"]
[SourceTitle "EXT 2024"]
[Source "ChessBase"]
[SourceDate "2023.10.10"]
[SourceVersion "1"]
[SourceVersionDate "2023.10.10"]
[SourceQuality "1"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. c4 Bg7 6. Be3 Nf6 7. Nc3 0-0 8. Be2 d6 9. 0-0 Ne5 10. h3 Be6 11. b3 a5 12. f4 Ned7 13. f5 gxf5 14. exf5 Bxc4 15. Bxc4 Ne5 16. Bd5 Nc6 17. Bxc6 bxc6 18. Rc1 c5 19. Nde2 d5 20. Bxc5 Rc8 21. Bd4 e6 22. Qd2 Ne4 23. Nxe4 dxe4 24. Rxc8 Bxd4+ 25. Nxd4 Qxc8 26. fxe6 fxe6 27. Qg5+ Kh8 28. Rxf8+ Qxf8 29. Qe5+ Kg8 30. Nxe6 Qe7 31. Qg5+ Qxg5 32. Nxg5 e3 33. Kf1 Kg7 34. Ke2 Kg6 35. g4 1-0

