E21 Nimzo-Indian: 4.Nf3 (1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.Nc3 Bb4 5.Bd2 Bb7 6.e3 O-O 7.Be2)

Another day, another opening variation. This game was played in the first round of the 28th Chess.com Tournament within the rating range of 1601-1800. I still have one game remaining in the group that I play but after that I need to wait for the other groups to finish so that I can see what is the group going to be like on the next round. The game you see below was decided when my opponent made a huge blunder on move 18...Qd5?? which is clearly the losing move of the game. My opponent played well up to that point so it is a shame that he played that move. I have added more puzzles to mate in one, two and four pages.

[Event "28th Chess.com Tournament (1601-1800) -"] [Site "Chess.com"] [Date "2014.09.01"] [Round "?"] [White "Vierjoki, Timo"] [Black "vanwie"] [Result "1-0"] [ECO "E21"] [WhiteElo "1862"] [BlackElo "1659"] [Annotator "Tactical Analysis 2.10 (5s), TV"] [PlyCount "77"] [EventDate "2014.??.??"] 1. d4 Nf6 (1... e6 2. c4 b6 3. Nc3 (3. Nf3 Bb7 4. e3 Nf6 {0-1 (27) Perez del Amo,J-Morales Rivera,J (2329) Madrid 2003}) 3... Bb7 4. Nf3 (4. e3 Nf6 5. Nf3 Bb4 {0-1 (28) De Cocq,R (1766)-Mitran,A (2080) Brasschaat 2018}) 4... Bb4 5. Bd2 {1/2-1/2 (15) Ballon,G (2219)-Koenig,C (2139) Bad Woerishofen 2003}) (1... b6 2. c4 Bb7 3. Nc3 {0-1 (28) De Cocq,R (1766)-Mitran,A (2080) Brasschaat 2018} ) 2. c4 e6 3. Nf3 b6 4. Nc3 {E12 Queen's Indian Defense: Kasparov Variation} Bb4 5. Bd2 Bb7 6. e3 O-O 7. Be2 {-0.34/22 E21 Nimzo-Indian: 4.Nf3} (7. Bd3 $14 {0.36/21}) 7... Be7 {0.51/19} (7... d6 $15 {-0.34/22}) 8. Qc2 {-0.25/21} (8. Rc1 $14 {0.51/19}) (8. O-O c5 {1-0 (100) Mieses Hernandez,D (1864)-Jaquez,J (2186) Santo Domingo 2017} 9. a3 d5 10. Rb1 cxd4 11. Nxd4 dxc4 12. Bxc4 Nbd7 13. Bxe6 fxe6 14. Nxe6 Qe8 15. Nxf8 Bxf8 16. b4 Qg6 17. f3 Ne5 18. e4 Kh8 19. Qe2 Rc8 20. Rfc1 Rd8 21. Be1 Nh5 22. Rd1 Nf4 23. Qf1 Rc8 {De Cocq,R (1766) -Mitran,A (2080) Brasschaat 2018 0-1}) 8... c5 {0.36/19} (8... d5 $11 {-0.25/21 }) 9. O-O {-0.14/21} (9. e4 $14 {0.36/19}) 9... Nc6 $146 {0.55/21} (9... cxd4 $11 {-0.14/21} 10. exd4 Nc6) (9... d6 10. a3 (10. dxc5 bxc5 11. Rfd1 Nc6 12. Be1 Qb6 13. Rac1 Rfd8 14. b3 Rac8 15. h3 h6 {1/2-1/2 (15) Ballon,G (2219) -Koenig,C (2139) Bad Woerishofen 2003}) (10. Rfd1 Nbd7 11. e4 cxd4 12. Nxd4 Rc8 13. Be3 Ne5 14. b3 Qc7 15. Ndb5 Qb8 16. Bf4 a6 17. Nd4 b5 18. Bxe5 dxe5 19. Nf3 b4 20. Na4 Nxe4 21. Nb6 Bc5 22. Nxc8 Nxf2 23. Ne7+ Kh8 24. Kf1 Ng4 {Perez del Amo,J-Morales Rivera,J (2329) Madrid 2003 0-1}) 10... Nbd7 11. Rad1 Rc8 12. Qb3 Qc7 13. d5 exd5 14. cxd5 c4 15. Qa2 Nxd5 16. Nd4 Nxc3 17. Bxc3 Ne5 18. f4 Nd7 19. Nf5 Nf6 20. Bxc4 Be4 21. Nxe7+ Qxe7 22. Bd4 b5 23. Bb3 Ng4 24. h3 {Mieses Hernandez,D (1864)-Jaquez,J (2186) Santo Domingo 2017 1-0 (100)}) 10. a3 { -0.37/21} (10. d5 $14 {0.55/21} exd5 11. Nxd5) 10... cxd4 $15 11. Nxd4 { -0.79/21} (11. exd4 $11 {0.12/23 remains equal.} d5 12. cxd5 Nxd5 13. Bd3) 11... Ne5 $2 {0.83/17} (11... Nxd4 $17 {-0.79/21} 12. exd4 d5) 12. b3 {-0.32/19 } ({White should try} 12. f4 $16 {0.83/17} Nc6 13. Nxc6 Bxc6 14. e4) 12... d5 13. cxd5 Nxd5 14. Ne4 {-0.74/20} (14. f4 $11 {0.05/24 keeps the balance.} Nd7 15. b4) 14... Rc8 $17 15. Qb2 Bf6 {0.09/21} (15... Nxe3 $1 $17 {-0.82/19} 16. Bxe3 Bxe4) 16. Nxf6+ {-0.62/21} (16. Rab1 $11 {0.09/21}) 16... Nxf6 $2 {1.13/21 } (16... Qxf6 $15 {-0.62/21 keeps the upper hand.} 17. Rfd1 Rfd8) 17. Bb4 { 0.46/24} (17. Rad1 $16 {1.13/21}) 17... Re8 $14 18. Rfd1 {[#] Black must now prevent Nxe6!} Qd5 $2 {3.75/19} (18... Nd5 $16 {0.86/22 might work better.}) 19. Nf3 $1 $18 Qe4 {5.44/18} (19... Nxf3+ $142 {3.59/23} 20. Bxf3 Qf5) 20. Qxe5 {White is clearly winning.} Qc2 21. Bc4 Qg6 {[#] And now ...Bxf3 would win.} 22. Qg3 a5 23. Bd6 a4 24. Qxg6 hxg6 25. Nd4 axb3 26. Bxb3 Rc3 27. Rdc1 Rec8 28. Rxc3 Rxc3 29. Bb4 Rc7 30. Nb5 Rd7 31. Rd1 Rxd1+ 32. Bxd1 Bc6 33. Nd4 Bb7 34. Bf3 Ba6 35. g3 Nd7 36. Bd6 Nc5 37. Bc6 Bb7 38. Bxb7 Nxb7 39. Bb4 {Accuracy: White = 26%, Black = 8%.} 1-0