Nice Exchange Sac from the Messchess Collection

[AdminX]

[d]br3qk1/2r2p2/5Qp1/1n1p3p/3P2N1/2p1P1P1/5PBP/R1R3K1 w - - 0 34
34. Rxa8!

[d]8/2r2B1k/r5p1/4N1qp/3PQ3/n1p1P1P1/5P1P/2R3K1 w - - 0 40
40. Rxc3!

[pgn] [Event "Banksia (Messchess) Game"] [Site "?"] [Date "2020.10.10"] [Round "?"] [White "Tasc Chess System R40 , (The King 2.50)"] [Black "Fidelity Elite AvantGarde , (Version 11)"] [Result "1-0"] [ECO "E15"] [PlyCount "107"] [EventDate "2020.??.??"] [TimeControl "40/7200+8:0"] 1. d4 {Ftacnik,L} Nf6 2. c4 e6 3. Nf3 b6 4. g3 Ba6 {E15: Queen's Indian, Nimzovich variation (exaggerated fianchetto)} 5. Nbd2 d5 6. cxd5 exd5 7. b4 { -0.54/23 E15: Queen's Indian: 4 g3 sidelines, 4 g3 Ba6 and 4 g3 Bb7 early deviations.} (7. Bg2 $14 {0.39/24}) 7... Bd6 $15 {[#]} 8. Qb3 $146 ({ Predecessor:} 8. e3 Bxf1 9. Kxf1 Qd7 10. Rb1 Qh3+ 11. Kg1 Nbd7 12. Qf1 Qf5 13. Kg2 h5 14. h4 O-O {0-1 (64) Hertneck,G (2615)-Nikolic,P (2625) Munich 1994 CBM 042 [Ftacnik,L]}) 8... c6 {0.01/27} (8... O-O $15 {-0.59/22}) 9. a4 $11 { The position is equal.} O-O 10. Bg2 Re8 (10... b5 {keeps more tension.} 11. a5 Re8 12. e3 Bc8 13. O-O Qe7) 11. e3 c5 12. b5 {-0.26/24} ({White should try} 12. dxc5 $1 {0.27/25} bxc5 13. b5) 12... Bb7 {0.25/25} (12... c4 $142 {-0.26/24} 13. Qc3 Bb7) 13. Ba3 Nbd7 14. O-O Qc7 15. Nh4 c4 {0.73/25} (15... h6 $11 { 0.01/22}) 16. Bxd6 $16 Qxd6 17. Qc2 {0.01/26} (17. Qa3 $16 {0.71/24} Qxa3 18. Rxa3) 17... Rac8 18. Rfc1 Rc7 19. Nf5 Qf8 $1 20. a5 g6 21. Nh4 (21. a6 $5 Ba8 22. Nh4 $11) 21... Ba8 {0.85/23} (21... Qd6 $11 {0.06/25}) 22. axb6 Nxb6 { 1.01/27} (22... axb6 $14 {0.51/25} 23. Nb1 Bb7) 23. Nhf3 Nc8 24. Nb1 Nd6 25. Nc3 Nfe4 26. Nxe4 Nxe4 27. Ne5 {Strongly threatening Bxe4.} Nd6 $1 28. Qa4 { -0.32/27} (28. Ra5 $14 {0.44/26}) 28... Rec8 {0.88/25} (28... Rb8 $15 {-0.32/ 27 stays ahead.}) 29. Nc6 {0.20/27} (29. Qa5 $1 $16 {0.88/25}) 29... a6 $2 { 1.79/28 [#]} (29... Nxb5 $1 $11 {0.20/27 and Black stays safe.} 30. Nb4 (30. Bxd5 Bxc6 31. Bxc6 Nxd4 $17) 30... Rd8) 30. Qxa6 $18 Nxb5 31. Ne5 $36 {Keeping Black busy.} ({And not} 31. Qxb5 Bxc6 32. Qa5 Qd6 $11) 31... Rb8 32. Qf6 c3 $2 {4.04/32} (32... Nd6 {1.77/26} 33. Qf4 Qe7) 33. Ng4 h5 34. Rxa8 $1 Rxa8 35. Bxd5 Kh7 36. Ne5 $1 ({Stronger than} 36. Bxa8 Qa3 $11) 36... Qd8 37. Qf3 Ra6 38. Bxf7 Na3 $2 {7.52/27} (38... Qe7 {3.77/28} 39. Bc4 Rb6) 39. Qe4 Qg5 40. Rxc3 $3 {[#] Deflection} Rxc3 41. Qb7 $1 Qxe5 42. dxe5 Rac6 43. e6 {White wants to mate with e7.} h4 44. e7 {White mates.} h3 45. f4 Rc1+ 46. Kf2 R6c2+ 47. Kf3 Rc8 48. e8=Q Rxe8 49. Bxe8+ Kh8 50. Bxg6 Rf1+ 51. Kg4 Rxf4+ 52. exf4 Kg8 53. Qf7+ Kh8 54. Qf8# {mate. Accuracy: White = 61%, Black = 34%.} 1-0 [/pgn]

[Paloma]

To Pos1:

br3qk1/2r2p2/5Qp1/1n1p3p/3P2N1/2p1P1P1/5PBP/R1R3K1 w - - 0 34

Analysis by Crystal 080420 64 bmi2:

1. +- (1.61): 34.Ne5 c2 35.Ra6 Qd8 36.Qxd8+ Rxd8 37.Ra2 Rdc8 38.Kf1 Kg7 39.Bh3 Rb8 40.Raxc2 Rxc2 41.Rxc2 Nd6 42.Ke2 Rb6 43.Rc7 g5 44.Bg2 Rb2+ 45.Ke1 Rb1+ 46.Kd2 Rb2+ 47.Rc2 Rb1 48.Rc1 Rb2+ 49.Ke1 Ne4 snip
2. +/- (1.08): 34.Rxa8 Rxa8 35.Bxd5 Kh7 36.Ne5 Qa3 37.Nxf7 Rf8 38.Kg2 Rd7 39.Be6 Qe7 40.Ng5+ Kh6 41.Qxe7 Rxe7 42.h4 Rc7 43.Bd5 Rfc8 44.Ne4 Rd8 45.Bb3 Ra7 46.Kf3 Ra3 47.Bc4 Nd6 48.Nxd6 Rxd6 49.Ke2 Rb6 snip

(, 10.10.2020)

34.Ne5 seems better here at depth 42 after around an hour