Saturday, January 6, 2018

Alan Lasser's Game of the Week

  A year ago I attempted to add real statistical fuel to the ancient argument of which piece is better, the bishop or the knight.  This year I have repeated the project to expand and improve it.  The weakness of my study is that my random database is the almost 500 games that have appeared in GOTW, an insignificant number compared to the data base of several million master games.  
   Last year's results left questions unanswered.  You have to exchange at least a pair of bishops to reach most endings, so the BXB move might average about once a game.  Other than themselves, who were the bishops really slaying?  Could the bishops be busy sniping pawns while the knights were more likely to be part of major combinations?  My previous study also neglected to tabulate the most important number;  which piece, the bishop or the knight, made the final move of the game, the move that convinced the opponent to resign.
    In this issue I present the new expanded study, but unfortunately my statistics are already slightly skewed.  I frequently play the Bad Opening, where you can get three pieces for the queen in several variations;  my long-term readers have seen sixteen of my games, as well as similar exchanges by computers and grandmasters.  Most players might see the three pieces for the queen once or twice a career, but there are enough of my own games included in my "random sample" for the numbers to be a bit unreal.  I decided to make an adjustment to this year’s study, in order to bring the numbers of BXQ down a bit, I removed nine of these games that had been in last year’s study.  After my adjustment, the knights captured 66 queens, the bishops 53;  and you could still argue that I should have made a bigger adjustment to the raw sample.
   So here are the results, in the sample of 497 games previously appearing in GOTW, the bishops ruled once again, making a total of 1367 captures while the knights managed only 1255;  the knights averaged 2.53 captures a game to the bishop’s 2.75.  The bishops were better at capturing rooks, knights, and bishops, the knights were better at capturing queens and pawns.  42% of all the knight captures were pawns, 31% of the bishop captures were pawns.   If you add all the captured points together(3261 for knights, 3732 for bishops), the knights take 6.56 points a game while the bishops slay 7.51.  If you look at the numbers per capture, the results are closer;  the knights averaged 2.60 points per capture while each bishop capture netted 2.73 points.  There was one surprising revelation in my study;  in the 497 games, a bishop captured a bishop 339 times and a knight captured a knight 339 times.  I wonder what that means.   Finally and most importantly, the moves causing resignation or delivering mate clearly favored the knight, 44 to 38.  Perhaps the argument can now be framed differently;  would you rather have the piece that captures the most points, or the piece that takes the most queens and kings?  Until a bigger study comes along, you can quote me.
   It was very complicated when the center dissolved and Black’s fate depended upon defending against the two passed center pawns.  Then White found 28.Rd7.
IM Denys Shmelov-Sam Schmakel
2017 North American Open
4.e4 d6 
[Event "2017 North American Open"][Site "Las Vegas"][Date "2017.12.28"][Round "?"][White "IM Denys Shmelov"][Black "Sam Schmakel"][Result "1-0"][BlackElo "2430"][ECO "E97"][WhiteElo "2420"]
1.d4 Nf6 2.c4 g6 $6 { +0.65/22 } ( 2...d5 { +0.27/20 } 3.Nf3 c6 4.cxd5 cxd55.Nc3 Nc6 6.Qb3 e6 7.Bf4 Qa5 8.e3 Nh5 9.Bg5 f6 10.Bh4 g5 11.g4 gxh4 12.gxh5 )3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Nf3 e5 7.O-O Nc6 8.d5 Ne7 9.b4 Nh5 10.Re1 f511.Ng5 Nf6 12.Bf3 c6 13.dxc6 bxc6 14.exf5 gxf5 15.b5 d5 $2 { +1.75/19 } ( 15...e4 { +0.44/19 } 16.Be2 h6{ 16...d5 17. bxc6 d4 18. c7 Qd7 19. Ba3 h6 20. Nh3 dxc3 21. Qxd7 Bxd7 22.Bxe7   +0.35   Stockfish } 17.Nh3 d5 18.cxd5 Nfxd5 ) ( 15...h6 16.Nh3 d517.cxd5 cxd5 18.Ba3 e4 19.Nf4 Re8 20.Be2 d4 21.Qb3+ Kh7 22.Rad1 Ng6 23.Nxg6Kxg6 24.Bc4 Kh7 25.Bf7 d3 26.h3 Bd7 27.Bxe8 Bxe8 28.Bc5 { +0.27   Stockfish }) 16.Ba3 $2 { +0.68/21 } ( 16.bxc6 { +1.75/19 } 16...e4{ 16...h6 17. c7 Qd7 18. Rxe5 Qxc7 19. Rxe7 Qxe7 20. Nxd5 Qe8 21. Nxf6+Bxf6 22. Rb1 hxg5 23. Bxa8 Be6 24. Bd5 Bxd5 25. Qxd5+   +2.51   Stockfish }17.cxd5 h6 18.Ngxe4 fxe4{ 18...Nxe4 19. Nxe4 fxe4 20. Bxe4 Nxc6 21. Rb1 Nd4 22. Bb2 Nf5 23. Bxg7Nxg7 24. d6 Be6 25. Bxa8 Qxa8   +2.71   Stockfish } 19.Ba3 Nxc6{ 19...Nf5  +3.51  Stockfish } 20.Bxf8 Qxf8 21.Nxe4{ 21. dxc6 exf3 22. c7 Kh8 23. Qxf3 Bd7 24. Rac1 Rc8 25. Nd5 Ng8 26. Qxf8Bxf8  +4.00   Stockfish } 21...Ne5 22.d6 Rb8 23.Rc1 Be6 24.Rc7 Rd8 25.Rxa7Nxe4 ) 16...e4 17.bxc6 $6 ( 17.cxd5 cxd518.Qb3{ 18. Rc1 Re8 19. Bh5 Ng6 20. h4 Bb7 21. Bc5 Rc8 22. Bxa7 Qd6 23. Bxg6 hxg6 +0.24   Stockfish } 18...h6 19.Bxe7 Qxe7 20.Nxd5 Nxd5 21.Qxd5+ Kh8 22.Qxa8Bxa1 23.Rxa1 hxg5 24.Bd1 Be6 25.Qc6 Qf6 26.Rb1 Bxa2 27.Rc1 Bg8{ 27...Be6 28. b6 axb6 29. Qxb6 Bd7 30. Qa7 Rf7 31. h3 Kh7 32. Bh5 Rg7 33.Qc5 g4 34. hxg4 fxg4   +0.08   Stockfish } 28.Qd7 Qg7 29.Qd2 Rf6 30.Rc8 Rb631.Qd5 { +0.67 } ) 17...h6 18.cxd5 ( 18.Nxd5 Nexd519.Bxf8 Qxf8 20.cxd5 hxg5 21.d6 Be6 22.Rc1 Rd8 23.d7 Bxd7 24.cxd7 exf3 25.Rc7{ +2.06   Stockfish } ) 18...hxg5 19.Qb3 Rf7 20.Rad1 Ng6 $6 ( 20...exf3  21.Bxe7 Rxe7 22.d6+ Rf7 23.Nd5 Kh7 24.Nb6{ 24. Ne7 Qf8 25. Qxf3 g4 26. Qd3 Ne8 27. Nxc8 Rxc8 28. d7 Rd8 29. Rxe8Rxe8 30. c7 Rd8 31. Qb5 a6 32. Qc6 Rfxd7 33. Rxd7 Qb4 34. Rxg7+ Kxg7 35.Qf6+ Kxf6 36. cxd8=Q+   +0.61   Stockfish } 24...axb6 25.Qxf7 Qf8 26.Qxf8Bxf8 27.gxf3 Kg7 28.Re5 Kg6 29.d7 Bxd7 30.cxd7 Rd8 +0.04 } ) 21.d6 $6 { +0.15/21 } ( 21.Be2{ +0.57/20 } 21...Ne5{ 21...Qb6 22. Na4 Qxb3 23. axb3 Ne5 24. Bb2 Ne8 25. Bh5 Nd6 26. Bxf7+ Kxf727. f3 Nd3 28. Bxg7 Kxg7 29. Re3 f4 30. Rxe4 Nxe4 31. fxe4    +0.52  Stockfish } 22.Nb5 Nfg4{ 22...Rb8 23. Bb2 Nfg4 24. h3 Nxf2 25. Kxf2 g4 26. c7 Rxc7 27. d6+ Rf7 28.Bxe5 Bxe5 29. Bc4 Kg7 30. Bxf7   +1.26   Stockfish } 23.Bc5{ 23. d6 Qb6 24. Rf1 Qxc6 25. Nc7 Kh7 26. Rc1 Rxc7 27. dxc7 Qb6 28. h3 Qxb329. axb3    +1.79   Stockfish } 23...Qa5 24.Bxg4 Nxg4 25.d6 a6 ) 21...exf3 ( 21...Qb6 22.d7 Nxd7 23.cxd7 Bxd7 24.Nxe4 fxe4 25.Bxe4 Rb8 26.Qxb6 Rxb6 27.Bc5Re6 28.Bd5 Nf4 29.Bxe6 Nxe6 { +0.22   Stockfish } ) 22.c7 ( 22.Nd5 Kh7 23.Ne7Rxe7 24.dxe7 Qc7 25.h4{ 25. Bb2 Ng4 26. g3 Rb8 27. e8=Q Rxb3 28. Bxg7 Rb6 29. Bf8 Nxf2 30. Re7+Qxe7 31. Bxe7 Nh3+ 32. Kf1 Rb2 33. Bc5 Rxh2 34. Ke1 Re2+ 35. Qxe2 fxe2  +1.90   Stockfish } 25...Nf4 26.Qxf3 g4 27.Qc3 Ne8 28.Qc5 g3 29.Rd8 gxf2+30.Qxf2 Nh3+ 31.gxh3 Qxc6 32.Rc1 Qe6 { +0.93   Stockfish } ) 22...Qd7 23.Re7( 23.Nd5 Nxd5 24.Qxd5 fxg2 25.Qxa8 Kh7 26.Qxg2 Kh6 27.Rc1 f4 28.h3 Bd4{ +0.47   Stockfish } ) 23...Nxe7 24.dxe7 Qxc7 ( 24...Qc6 25.Rd6 Qxc7 26.Rxf6Be6 27.Rxe6 Qxc3 28.e8=Q+ Rxe8 29.Rxe8+ Kh7 30.Qxc3 Bxc3 31.gxf3{ +0.43   Stockfish } ) 25.Nd5 Nxd5 $4 { +10.98/24 } ( 25...Be6 { +0.15/23 }26.Nxc7 Bxb3 27.axb3{ 27. Rd8+ Kh7 28. Rxa8 Ba4 29. gxf3 Bc6 30. Rxa7 Ne8 31. Ra6 Bd7 32. Nxe8Bxe8 33. Ra8 Bc6 34. Rc8 Bd7 35. Rd8 Bc6 36. Bc5 Rf6 37. e8=Q Bxe8 38. Rxe8  +1.05   Stockfish } 27...Rxe7 28.Bxe7 Rb8 29.gxf3 Rb7 30.Bd6 Rxb3 31.Ne6 g432.fxg4 ) 26.e8=Q+ Bf8 ( 26...Kh7 27.Qxd5 Rf6 28.Qxa8 Be6 29.Qxf3{ +17.17   Stockfish } ) 27.Rxd5 Rb8 28.Rd7 Qxd7 29.Qxf8+{ 29...Kh7 30.Q3f7 Qf7 31.Qf7 Kh8 32.Bb2 Rb2 33.Qf6 Kg8 34.Qb2  is convincing. } 1-0