<INTRODUCTION>

Lasker vs Schlechter, 1910 is the <sixth game of the 1910 title match>.

Quantitative mapping of this game between these players is below. Figures in brackets immediately after each move are the corrected engine evaluations generated on the return slide, which smoothed out many, but not all fluctuation in the engine’s evaluations. The complexity of some variations was very likely too great to enable a fuller reconciliation from the initial reverse slide. However, where there were anomalies in the evaluations of the engine’s first preferences between consecutive moves, every effort was made to remedy them through extra sliding analysis. <General methods used are described in the bio at User: bridgeburner.;

The evaluation values in the opening come at the end of a full return slide back to the starting position from the last move of the game. Engine preferences are included throughout the game where they differ from players preferences. Some analysis in included to provide some idea of the reason for the engine preferences where they didn’t coincide with the moves played, except in situations where the evaluation differences were very minor.

<Summary>

<THE GAME>

<GAME MOVES 1-8>:

<1. e4> (=0.25) <1…e5> ( 0.33)

<2. Nf3> ( 0.32) <2…Nc6> ( 0.32)

<3. Bb5> ( 0.28) <3…a6> ( 0.28)

<4. Ba4> (=0.18) <4…Nf6> (=0.17)

<5. 0-0> (=0.13) <5…Nxe4> (=0.22)

<6. d4> ( 0.22) <6…b5> (=0.22)

<7. Bb3> (=0.22) <7…d5> (=0.22)

<8. a4> (=-0.22)

<Engine preferences>:

1. <8. Nxe5> (=0.22); (<8…Nxe5 9. dxe5> and <9…c6> or <9…Bb7> or <9…Be6> protect the d-pawn. Equality.

2. <8. dxe5> (=0.19); overwhelmingly the main line. <8…Be6> is universal and virtually forced. Equality.

3. <8. Re1> (=-0.17); preferred by the engine to <8. a4> but virtually unknown to theory as it is only fractionally (if any) better than that move. There might follow <8…Be6 9. dxe5 (or even <9. Nc3 Nxc3 10. bxc3> Bc5 10. Be3>. Equality.

<GAME MOVE>: <8…Rb8> ( 0.40)

<This is a <dubious move> representing an evaluation shift of <<0.62>> and therefore weighted at <<0.5>>.>

Capablanca commented that <Lasker insists on a move that he admits gives him no advantage, and Schlechter makes this inferior move instead of 8…Nxd4 9.Nxd4 exd4 10. axb5 Bc5 11.c3 0-0.>

Engine preferences:

1. <8…Nxd4> (=-0.22) (as per Capablanca’s variation) 2. <8…b4> (=0.19) (<9. dxe5 Be6 10. a5 Nc5>) 3. <8…Be6> (=0.19) (9. dxe5 b4 10. a5 Nc5>)

<GAME MOVES 9 & 10>:

<9. axb5> ( 0.40) <9…axb5> ( 0.40)

<10. dxe5> ( 0.40) <10…Be6> ( 0.40)

<GAME MOVES 11-15>:

<11. c3> ( 0.40) <11…Bc5> ( 0.40)

Capablanca: <Better, I believe, than ,11…Be7 as he played in the fourth game.>

<12. Nbd2> ( 0.40) <12…0-0> ( 0.40)

<13. Bc2> ( 0.40) <13…Nxd2> ( 0.40)

<14. Qxd2> ( 0.40) <14…Qd7> ( 0.53)

<Engine preference>: <14…Bg4> ( 0.40), eg: <15. Qd3 g6 16.Bg5 Nxe4> or <16. Rd1 Bxf3 17. Qxf3 Nxe5 18. Qxd5 Qxd5 19. Rxd5 Bxd6>.

<GAME MOVE 15>: <15. b4> ( 0.53) <15…Be7> ( 0.61):

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<Engine preference>: <15…Bb6> ( 0.53); (<16. Qd3 g6 17. Bg5 d4>:

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<GAME MOVE 16>: <16. Re1> ( 0.55):

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<GAME MOVE 16>:

<16…f6> ( 0.68)

<Engine preferences>:

1. <16…Ra8> ( 0.55) (<17. Rxa8 Rxa8 18.Bd3 Rb8 19.Qc2 g6 20. Rd1 Nd8 21. Bf4 Ra8 22. Nd4 c6>:

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2. <16…Bg4> ( 0.63) (<17. Ng5 Bxg5 18. Qxg5 Ne7 19. Be3 h6 20. Qf4 Bf5 21. Bb3>)

<GAME MOVES 17-19>:

<17. Qd3> ( 0.68) <17…g6> ( 0.68)

<18. Bh6> ( 0.68) <18…Rfe8> ( 0.68)

<19. exf6> ( 0.68)

Departs from <19. Bb3> played in Maroczy vs G Marco, 1900, which White won in 47 moves.

Capablanca: <19. Ra6 should be considered. If 19…fxe5, then I believe 20. Rxc6 would win, as after 20…Qxc6 21.Nxe5, threatening 22. Nxg6, to which Black seems to have no defence. Also if 19…Bf5 20. e6!>

Note: If <19. Ra6>, Black has <19…Nxe5> solving all problems, eg: with the following forceful sequence of moves: <20. Nxe5 fxe5 21. Rxe5 Bf5 22. Qd1 Bxc2 23. Qxc2 Bd6>:

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<GAME MOVES 19 & 20>:

<19…Bxf6> ( 0.68)

<20. Bb3> ( 0.68) <20…Bf7> ( 0.73)

<Engine preference>: <20…Kh8> ( 0.68)

The game has now entered its critical juncture:

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<GAME MOVE 21>: <21. Rad1?!> (=0.00)

<This is a <dubious move> as it represents an evaluation shift of 0.73. Weighting is therefore <<0.50>> for an accumulated game weighting of <<1.0>>.>

<Engine preferences>:

1. <21. Re8+> ( 0.73) (<21…Qxe8 (if <21…Rxe8 22. Qxb5> wins the b-pawn) 22. Re1 (if <22. Bxd5 Rd8 23. Bxf7+ (if <23. Re1 Ne5 24. Bxf7+ Kxf7 25. Nxe5+ Qxe5>=) 23…Qxf7 24. Qxb5 Bxc3 25. Rc1 Nxb4> is roughly equal) 22…Qd7 23. Qd2>:

Position A

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If <23…Re8 24. Rxe8+ Qxe8 25. Bxd5 Ne5 26. Bxf7+ Nxf7 27. Be3>:

Position B

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With moderate advantage for White in a difficult Queen and two minor pieces each endgame.

Other alternatives favor White even more; from Position A, if <23…Qf5 24. Ng5 Bxg5 25. Bxg5>:

Position C

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If <25…Ra8 26. Bc2 Qd7 27. Bd3 Rb8 28. h4 >, or <27…Nd8 28. h4 c6 29. h5 Qg4 30. hxg6 hxg6 31. Bf6 Ne6 32. Qh6 Qh5 33. Qe3 Qg4 34. Be5 > or

If <25…d4 26. Bxf7+ Qxf7 27. cxd4> with an extra pawn and a significant advantage; or

If <25…Qd7 26. h3 Ra8 27. Be3 d4 28. Bxf7+ Kxf7 29. Bxd4 Nxd4 30. cxd4> with an extra pawn and significant advantage, albeit in a difficult heavy piece ending:

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<Engine preferences 2 & 3>:

2. <21. Bf4> ( 0.45) 3. <21. h3> ( 0.34)

<GAME MOVE 22>

<22. Nxe5> (=0.00) <22…Bxe5> ( 0.57)

<Engine preference>: <22…Rxe5> (=0.00) <23. Be3 Rbe8 24. Rf1 (24. Ra1 Bg5) Re4> or <23. Qd2 Rxe1+ 24.Rxe1 Qc6 25. Rc1 Ra8 26. h3 Be6 27. Qf4 Bf7>

<GAME MOVE 23>: <23. h3> ( 0.57) <23…Qd6> (=0.63)

<Engine preferences>:

1. <23…Bf6> ( 0.57) 2. <23…Bh8> ( 0.57)

Capablanca: <There seems no good reason for giving up a pawn here. 23…c6 seems safe enough.>

Note: <23…c6 24. Rxe5> wins a piece as Black cannot recapture without losing the rook: <25….Rxe5 26. Qd4 Rbe8 27. f4 Re1+ 28. Rxe1 Rxe1+ 29. Kf2> and Black loses the rook due to the threat of mate in one on g7.

<GAME MOVES 24-32>:

<24. Bxd5> ( 0.63) <24…Bxd5> ( 0.63)

<25. Qxd5> ( 0.63) <25…Qxd5> ( 0.63)

<26. Rxd5> ( 0.63) <26…Bxc3> ( 0.63)

<27. Rxe8+> ( 0.63) <27…Rxe8> ( 0.63)

<28. Rxb5> ( 0.63) <28…Re4> ( 0.67)

<Engine preference>: <28…Re1+> ( 0.63)

<29. Rb8+> ( 0.67) <29…Kf7> ( 0.67)

<30. b5> ( 0.67) <30…Re1+> ( 0.68)

<Engine preference>: <30…Ke6> ( 0.67)

<31. Kh2> ( 0.68) <31…Be5+> ( 0.68)

<32. f4> ( 0.68)

<Capablanca>: <This move is weak; it blocks the diagonal of the white bishop. 32. g3 was the right move. If then 32…Re2 33. Kg2 Bd4 34. Rf8+ Ke7 35. Rf4 Rb6 36.Bg5+, with winning chances. After the text move, Black forces a draw very cleverly.>

<GAME MOVES 32-33>:

<32…Bd4> ( 0.68)

<33. Kg3> ( 0.68) <33…Re3+> ( 0.69)

<Engine preference>: <33…Rc1> ( 0.68)

<GAME MOVE 34>: <34. Kg4> ( 0.67)

<Engine preference>: <34. Kh2> ( 0.69)

<GAME MOVE 34>: <34…Rb3> ( 0.74)

<Engine preference>: <34…Rc3> ( 0.67) <35. Rf8+ Ke6 36.Re8+ Kf7 37.Re2> and now <37…c6 and 37…c5 and 37…Bc5> flatline at 0.68, indicating a very drawish set of continuations.

<GAME MOVE 35>: <35. f5> ( 0.41)

<Engine preference>:

1. <35. Rc8> ( 0.74) 2. <35. Rd8> ( 0.47)

<GAME MOVE 35> <35…Rb4> ( 0.57)

<Engine preferences>:

1. <35…Be5> ( 0.41) <36.Rf8+ Ke7 37.fxg6 hxg6 38.Rf3 Rb2 39.g3 Rxb5 40.Kg5 Bxg3+ 41.Kxg6 Rb6+ 42.Kh7 Be5 43.h4 Ke6 44.h5 Kd5 45.Bg7 Ke4>

2. <35...Kf6> ( 0.52): <36.Bg5+ Kg7 37.Bd2 Rb2 38.Ba5 Be5 39.fxg6 Kxg6 40.Kf3 c6 41.Rb6 Rxb5 42.Rxc6+ Kf7 43.Bd2 Rb3+ 44.Ke4 Bf6>

<GAME MOVE 36>: <36. fxg6+> ( 0.45)

<GAME MOVES 36-39>

<36…Kxg6> ( 0.45)

<37. Bf4> ( 0.45 ) <37…Be5> ( 0.45)

<38. g3> ( 0.45 ) <38…c6> ( 0.45)

<39. Rb6> (=0.05)

<First three engine preferences>:

1. <39. Rg8+> ( 0.45): <39…Kf7 40.Rc8 Rxb5 41.Bxe5 Rxe5 42.Rc7+ Kg6 43.Rxc6+ Kg7 44.Kf3 h5 45.Kf4 Rb5 46.Re6 Rb4+ 47.Re4 Rb6 48.Kg5 Rb5+ 49.Kh4 Kf6 50.Rf4+ Kg6 51.Rc4>

2. <39. Re8> ( 0.30): <39…h5+ 40.Kf3 Bxf4 41.gxf4 cxb5 42.Re6+ Kf7 43.Rb6 Rb3+ 44.Ke4 Rxh3 45.Kf5 Rg3 46.Rb7+ Kg8 47.Rxb5 h4 48.Ke4 h3 49.Rh5 Kf7 50.Kf5>

3. <39. Rc8> (=0.21): <39…h5+ 40.Kf3 Bxf4 41.gxf4 cxb5 42.h4 Rc4 43.Rg8+ Kh6 44.Rb8 b4 45.Rb7 Kg6>

<GAME MOVES 39-47>:

<39…h5+> (=0.05)

<40. Kf3> (=0.05)

But not <40. Kh4?? Bf6#>

<40…Bxf4> (=0.05)

<41. gxf4> (=0.05 <41…Kf5> (=0.05)

<42. Rxc6> (=0.05) <42…Rb3+> (=0.05)

<43. Kg2> (=0.00)

<Engine preference>: <43. Kf2> (=0.05)

<43…Kxf4> (=0.00)

<44. Rc4+> (=0.00) <44…Kg5> (=0.00)

<45. Rc5+> (=0.00) <45…Kh4> (=0.00)

<46. Re5> (=0.00) <46…Rg3+> (=0.05))

Missing <46…Rxb5 47.Rxb5 stalemate.>

<47. Kf2> (=0.05) <47…Rxh3> (=0.05)

Agreed drawn. Final position:

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<ANALYSIS>

<Note> The fluctuations generated in the relatively low (16 minimum) ply initial reverse slide were smoothed out as far as possible in the return forward slide. The corrected evaluations extracted from the return forward slide are used in this analysis, as they are considered more reliable than the raw evaluations generated on the initial reverse slide. All moves have been evaluated on forward and return slide for completeness.

Additionally, some variation analyses was used to evaluate "reasons" for some of the engine preferences.

<Evaluation range>:

Between <-0.22> (equality) applying to <8. a4> - and < 0.74> in respect of move <43...Rb3> representing a moderate advantage for White.

<The largest evaluation shifts>:

- in favor of White was 0.62 between <8. a4> ((-0.22), equality) and <8…Rb8> (( 0.40), a slight advantage for White.

- in favor of Black was 0.73 between <20…Nf7> (( 0.73 ) – a moderate advantage for White) and <21. Rad1> ((=0.11) – equality).

<CONCLUSION>

<The game is weighted at <<1.0>>representing <<1 dubious move>> (0.5) by Schlechter plus <<1 dubious move>> (0.5) by Lasker.>

<Schlechter’s dubious move was <<8…Rb8>> conceding a slight advantage to Lasker.

Position A in post <Part 5> has a misplaced white queen. It should be at d2 instead of d3.

Capablanca commented that <Lasker insists on a move that he admits gives him no advantage, and Schlechter makes this inferior move instead of 8…Nxd4 9.Nxd4 exd4 10. axb5 Bc5 11.c3 0-0.>>