Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than Qa4

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Vinvin
Posts: 4014
Joined: Thu Mar 09, 2006 8:40 am

Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than Qa4

Post by Vinvin » Fri Nov 24, 2017 1:20 am

From the article : https://en.chessbase.com/post/tcec-supe ... -vs-komodo
...needed only 16 seconds to find 1.Qxd7! ...still shows the clearly weaker move 1.Qa4.
In 2 best lines mode, McBrain 3.0 continues to prefer Qa4. And it seems right.
Why does CB claims Qxd7 is better than Qa4 ?

Code: Select all

FEN: r2r2q1/2Rn2bk/b2N2pp/pQ2p3/4Pp2/B4N1P/5PP1/2R3K1 w - - 2 31

McBrain_2017_v30_TCEC-x86-64-modern:
...
 33/52	00:58	 584 740k	10 079k	+3,39	31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3 34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+ 37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8 40.Rxg6+ Kh7 41.Rg7+ Kh8 42.f3 Rf1 43.Ra7+ Kg8 44.Rxa5 Rb1 45.Bxf4 Rb6 46.h4 Ra6 47.Rc5 Bd1 48.Kg3 Kg7 49.h5 Bb3 50.Rc7+ Kf8 51.Rc8+ Kg7 52.Be5+ Kf7 53.Rc7+ Kg8 54.Kf4 Bd1 55.Rc8+ Kf7 56.Rc1 Be2
 33/66	00:58	 584 740k	10 079k	+3,99	31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Rxd6 34.Bxd6 Qxd6 35.R1c6 Nc4 36.Rxd6 Nxa5 37.Nxe5 Rc8 38.Rxg7+ Kxg7 39.Rxg6+ Kh7 40.Rxa6 Nb3 41.f3 Nd4 42.Rd6 Ne2 43.Rd7+ Kg8 44.Ng6 Re8 45.Ne7+ Kf8 46.Nf5 Re6 47.Rh7 Nc3 48.h4 Nd1 49.Rxh6 Rxh6 50.Nxh6 Kg7 51.Nf5+ Kf6 52.g4 Nf2 53.h5 Kg5 54.Nd4 Nd3 55.Kg2 Kf6 56.Kh3 Kg5 57.Ne6+ Kf6
---------------------------------------------------------------------------
 34/57	01:38	 1 006 303k	10 244k	+3,39	31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3 34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+ 37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8 40.Rxg6+ Kh7 41.Rg7+ Kh8 42.f3 Rf1 43.Ra7+ Kg8 44.Rxa5 Rb1 45.Bxf4 Rb6 46.h4 Ra6 47.Rc5 Bd1 48.Kg3 Bb3 49.h5 Kf8 50.Rc7 Kg8 51.Rc8+ Kg7 52.Be5+ Kf7 53.Rc7+ Kg8 54.Kf4 Bd1 55.Rc1 Ba4 56.Rc8+ Kf7 57.g4 Bd1 58.Rc7+ Ke8 59.Rc1
 34/72	01:38	 1 006 303k	10 244k	+4,08	31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7 34.Qe1 Bd3 35.Bb4 Ra6 36.Nb7 Rda8 37.Qd2 Bb5 38.Nc5 Nxc5 39.R1xc5 Rd6 40.Qc3 Bd7 41.Rxe5 Bxe5 42.Qxe5 Rc6 43.Qxe6 Rxe6 44.Rxd7+ Kg8 45.e5 g5 46.Be7 Rg6 47.Nd4 Ra4 48.Bf6 Ra6 49.h4 gxh4 50.Nf3 Rg4 51.Kh3 h5 52.Nxh4
---------------------------------------------------------------------------
 35/62	02:37	 1 625 161k	10 331k	+3,50	31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3 34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+ 37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8 40.Rxg6+ Kh7 41.Rg7+ Kh8 42.f3 Rf1 43.Ra7+ Kg8 44.Rxa5 Rb1 45.Bxf4 Rb6 46.h4 Bf1 47.Rc5 Rf6 48.Kg3 Rb6 49.Kf2 Ba6 50.g4 Bb7 51.Be5 Bc6 52.Kg3 Ba4 53.Rc8+ Kf7 54.Bf4 Kg7 55.h5 Kf7 56.Rd8 Ra6 57.Rh8 Kg7 58.Rc8 Kf7 59.Kf2 Bd1 60.Rd8 Bb3
 35/60	02:37	 1 625 161k	10 331k	+4,28	31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7 34.Qe1 Rdb8 35.R1c6 Bd3 36.Nc4 Bxc4 37.Rxe6 Bxe6 38.Qc3 Ra6 39.Qd3 Rba8 40.Bb2 R8a7 41.Rxa7 Rxa7 42.Qd6 Nf8 43.Bxe5 Rd7 44.Qc5 Bg8 45.Qc8 g5 46.Bxg7 Kxg7 47.Ne5 Re7 48.Qc3 Re6 49.Ng4+ Kf7 50.Qc7+ Kg6 51.Qd8 Kg7 52.Qd4+ Kf7 53.Qc3
---------------------------------------------------------------------------
 36/60	02:57	 1 830 411k	10 308k	+3,50	31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3 34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+ 37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8 40.Rxg6+ Kh7 41.Rg7+ Kh8 42.f3 Rf1 43.Ra7+ Kg8 44.Rxa5 Rb1 45.Bxf4 Rb6 46.h4 Bf1 47.Rc5 Rf6 48.Kg3 Rb6 49.Kf2 Ba6 50.g4 Bb7 51.Be5 Bc6 52.Kg3 Ba4 53.Rc8+ Kf7 54.Bf4 Kg7 55.h5 Kf7 56.Rd8 Ra6 57.Rh8 Kg7 58.Rc8 Kf7 59.Kf2 Bd1 60.Rd8 Ba4
 36/60	02:57	 1 830 411k	10 308k	+4,28	31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7 34.Qe1 Rdb8 35.R1c6 Rg8 36.Qd2 Nb8 37.Rc3 Nd7 38.Bb2 Rad8 39.Rc1 Nf6 40.Bxe5 Rxd6 41.Bxd6 Nxe4 42.Qb4 Qxd6 43.Qxe4 Bd3 44.Qa4 Qb6 45.Qxf4 g5 46.Qe5 Qg6 47.Qg3 Bb5 48.Ne5 Qd6 49.f4 Qd2 50.f5 Kh8 51.Nf7+ Kh7 52.Nd6 Ba4

carldaman
Posts: 1537
Joined: Sat Jun 02, 2012 12:13 am

Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by carldaman » Fri Nov 24, 2017 2:04 am

The author of the article, and others like him, tend to make up their mind beforehand that the move played by the GM is necessarily the best, since the game was quickly won, and any other moves must automatically be inferior.

The move played was certainly brilliant but it was not the only winning move, and not necessarily the most accurate, though that hardly matters here. It certainly wasn't risk-free.

User avatar
Eelco de Groot
Posts: 3818
Joined: Sun Mar 12, 2006 1:40 am
Location: Groningen

Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by Eelco de Groot » Fri Nov 24, 2017 2:13 am

http://www.chessgames.com/perl/chessgame?gid=1108797


[pgn][Event "Biel Interzonal"]
[Site "Biel SUI"]
[Date "1993.07.22"]
[EventDate "?"]
[Round "6"]
[Result "1-0"]
[White "Jeroen Piket"]
[Black "Ilya Smirin"]
[ECO "E94"]
[WhiteElo "2590"]
[BlackElo "2640"]
[PlyCount "71"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5
7. O-O Na6 8. Be3 Ng4 9. Bg5 Qe8 10. dxe5 dxe5 11. h3 h6
12. Bd2 Nf6 13. Be3 Nd7 14. a3 f5 15. b4 c6 16. c5 f4 17. Bc1
Kh7 18. Bb2 Nc7 19. Nb1 Ne6 20. Nbd2 Nd4 21. Nc4 Nxe2+
22. Qxe2 b6 23. Nd6 Qe6 24. Rfd1 bxc5 25. Rac1 cxb4 26. Rxc6
bxa3 27. Bxa3 Rd8 28. Rdc1 Qg8 29. Rc7 a5 30. Qb5 Ba6 31. Qxd7
Rxd7 32. Rxd7 Rd8 33. Re7 Be2 34. Nxe5 Qa2 35. Rcc7 Rg8
36. Ne8 1-0[/pgn]


r2r2q1/2Rn2bk/b2N2pp/pQ2p3/4Pp2/B4N1P/5PP1/2R3K1 w - -

Engine: Kaissa HT (4 threads + 3 hyper, i7 6700, 512 MB)
Stockfish 20170922 based. Latest changes: Zugzwang detection Lite :) .
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

20/40 0:01 +1.19 31.Qa4 Qe6 32.R1c6 Qa2 33.Rc2 Qe6
34.Kh2 Nb6 35.Qc6 Nd7 36.Rd2 a4
37.Rd5 Be2 38.Nb7 Qxc6 39.Rxc6 Rg8
40.Rxd7 Bb5 41.Rcd6 Bxd7 42.Rxd7 Ra7
43.Nxe5 Rb8 44.Nc5 (16.242.004) 10325

21/46 0:01 +1.19 31.Qa4 Qe6 32.R1c6 Qa2 33.Rc2 Qe6
34.Kh2 Nb6 35.Qc6 Nd7 36.Rd2 a4
37.Rd5 Be2 38.Nb7 Qxc6 39.Rxc6 Rg8
40.Rxd7 Bb5 41.Nxe5 Rae8 42.Nd6 Rxe5
43.Nxb5 Rxb5 44.Ra6 (20.203.480) 10414

22/45 0:02 +1.17 31.Qa4 Qe6 32.R1c6 Qa2 33.Rc2 Qe6
34.Kh2 Nb6 35.Qc6 Nd7 36.Rd2 a4
37.Rd5 Be2 38.Nb7 Qxc6 39.Rxc6 Rg8
40.Rxd7 Bb5 41.Nxe5 Rae8 42.Nd6 Rxe5
43.Nxb5 Rxb5 44.Ra6 (23.884.272) 10503

23/55 0:02 +1.24 31.Qa4 Qe6 32.R1c6 Qa2 33.Rc2 Qe6
34.Kh2 Nb6 35.Qc6 Nd7 36.Rd2 a4
37.Rd5 Be2 38.Nb7 Qxc6 39.Rxc6 Rg8
40.Rxd7 Bb5 41.Nxe5 Rae8 42.Nd6 Rxe5
43.Nxb5 Rxb5 44.Ra6 (28.151.072) 10547
.
.
.
28/50 0:29 +2.58 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7
34.Qd2 Kg8 35.R1c6 Nb8 36.Rxg7+ Kxg7
37.Rb6 Kh7 38.Qa5 Nd7 39.Rxa6 Rxa6
40.Qxa6 Rg8 41.Qa7 Rg7 42.Bb4 Qb3
43.Qa5 Qe6 44.Kg1 (303.131.654) 10286

29/49 0:36 +2.65++ 31.Qa4 (371.245.404) 10274

29/49 0:39 +2.73++ 31.Qa4 (402.311.461) 10266

29/49 0:44 +2.84++ 31.Qa4 (457.471.389) 10259

29/50 0:52 +3.00++ 31.Qa4 (542.005.430) 10231

29/50 0:59 +2.72 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7
34.Qd2 Nf6 35.R1c6 Rd7 36.Qb4 Rxc7
37.Rxc7 Ne8 38.Nxe8 Rxe8 39.Bb2 Kg8
40.Rxg7+ Kxg7 41.Nxe5 g5 42.Qd4 Qf6
43.Qd5 Qe6 44.Nd7+ (610.347.882) 10195

30/44 1:05 +2.79++ 31.Qa4 (669.888.462) 10187

30/49 1:08 +2.87++ 31.Qa4 (700.109.614) 10198

30/53 1:14 +2.97 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7
34.Qd2 Kg8 35.R1c6 Nb8 36.Rxg7+ Kxg7
37.Rb6 Kh7 38.Qa5 Nd7 39.Rxa6 Rxa6
40.Qxa6 Nf6 41.Nxe5 Qxe5 42.Nf7 Qd4
43.Nxd8 Qxd8 44.Bb2 (757.861.392) 10211

31/61 1:27 +3.05++ 31.Qa4 (897.462.570) 10234

31/61 1:42 +3.07 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7
34.Qd2 Nf6 35.R1c6 Rd7 36.Qb4 Rxc7
37.Rxc7 Ne8 38.Nxe8 Rxe8 39.Bb2 Kg8
40.Rxg7+ Kxg7 41.Nxe5 Rc8 42.Ng4+ Kf7
43.Qd4 Ke8 44.Nf6+ (1.039.437.388) 10190

32/49 2:11 +2.99-- 31.Qa4 Qe6 (1.342.821.633) 10174

32/57 2:19 +3.07++ 31.Qa4 (1.420.751.989) 10179

32/57 2:27 +3.18++ 31.Qa4 (1.503.187.123) 10202

32/57 2:39 +3.24 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7
34.Qd2 Nf6 35.R1c6 Rd7 36.Qb4 Be2
37.Nc4 Qe8 38.Nfxe5 Rxc7 39.Rxc7 Bxc4
40.Nxc4 Rb8 41.Qc5 Nh5 42.Bb2 Qf8
43.Qa7 Ra8 44.Qb7 (1.630.311.043) 10194

33/52 3:39 +3.30 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Nd7
34.Qd2 Kg8 35.R1c6 Nb8 36.Rxg7+ Kxg7
37.Rb6 Kh7 38.Qa5 Nd7 39.Rxa6 Rxa6
40.Qxa6 Nf6 41.Qa7+ Rd7 42.Qc5 Qe7
43.Nxe5 Qxd6 44.Qxd6 (2.221.467.790) 10127

34/25 3:53 +3.22-- 31.Qa4 Qe6 (2.363.730.117) 10125


34/53 5:18 +3.30++ 31.Qxd7 (3.264.332.799) 10239

34/58 5:33 +3.41++ 31.Qxd7 (3.426.886.557) 10270

34/58 5:51 +3.57++ 31.Qxd7 (3.619.175.156) 10307

34/61 6:55 +3.78++ 31.Qxd7 (4.324.060.201) 10411

34/63 7:51 +3.99 31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3
34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+
37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8
40.Rxg6+ Kh7 41.Rg7+ Kh8 42.Ra7+ Kg8
43.Bxf4 Rf1 44.Kg3 (4.947.670.983) 10496

35/67 8:43 +4.07++ 31.Qxd7 (5.525.986.229) 10559

35/67 9:36 +4.14++ 31.Qxd7 (6.123.302.143) 10616

35/67 11:04 +4.25++ 31.Qxd7 (7.112.167.378) 10697

35/67 12:34 +4.36 31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3
34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+
37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8
40.Rxg6+ Kh7 41.Rg7+ Kh8 42.Ra7+ Kg8
43.Bxf4 h5 44.Rxa5 (8.104.066.484) 10745

36/68 14:15 +4.36 31.Qxd7 Rxd7 32.Rxd7 Rb8 33.Rcc7 Kh8
34.Nh4 Bc8 35.Nxg6+ Kh7 36.Ne7 Bxd7
37.Nxg8 Kxg8 38.Rxd7 Bf8 39.Ra7 a4
40.Rxa4 Rb1+ 41.Kh2 Ra1 42.Ra8 Rxa3
43.Rxa3 Bxd6 44.Ra5 (9.268.282.779) 10834

37/57 15:18 +4.43++ 31.Qxd7 (9.979.379.437) 10862

37/57 15:53 +4.51++ 31.Qxd7 (10.367.953.584) 10876

37/62 17:12 +4.62++ 31.Qxd7 (11.271.607.273) 10915

37/77 20:49 +4.78++ 31.Qxd7 (13.778.982.556) 11023

37/77 22:03 +4.78 31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3
34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+
37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8
40.Rxg6+ Kh7 41.Rg7+ Kh8 42.Ra7+ Kg8
43.Bxf4 Bd3 44.f3 (14.619.184.325) 11045
Last edited by Eelco de Groot on Fri Nov 24, 2017 2:23 am, edited 1 time in total.
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan

Vinvin
Posts: 4014
Joined: Thu Mar 09, 2006 8:40 am

Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by Vinvin » Fri Nov 24, 2017 2:17 am

Eelco de Groot wrote:
34/25 3:53 +3.22-- 31.Qa4 Qe6 (2.363.730.117) 10125

34/53 5:18 +3.30++ 31.Qxd7 (3.264.332.799) 10239
Please, use the 2 best moves mode to compare the 2 eval.

User avatar
Eelco de Groot
Posts: 3818
Joined: Sun Mar 12, 2006 1:40 am
Location: Groningen

Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by Eelco de Groot » Fri Nov 24, 2017 3:30 am

Vinvin wrote:
Eelco de Groot wrote:
34/25 3:53 +3.22-- 31.Qa4 Qe6 (2.363.730.117) 10125

34/53 5:18 +3.30++ 31.Qxd7 (3.264.332.799) 10239
Please, use the 2 best moves mode to compare the 2 eval.
Hi Vincent, is running. The difference is probably that McBrain, SugaR and Stockfish think a opp. bishop endgame is drawish, and Crafty 23.4 (not Houdini as I wrote first, at least that was not mentioned in the article) thinks with white passed pawns is not. A question of taste, if you do that :} (It is not always to say with certainty)

Typical last position I see in Shredder GUI for 31. Qxd7 in Multi PV:

[D]6k1/8/7p/8/R3PB2/7P/4bPPK/3r4 w - -
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan

User avatar
MikeB
Posts: 2505
Joined: Thu Mar 09, 2006 5:34 am
Location: Pen Argyl, Pennsylvania

Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by MikeB » Fri Nov 24, 2017 4:28 am

Eelco de Groot wrote:
Vinvin wrote:
Eelco de Groot wrote:
34/25 3:53 +3.22-- 31.Qa4 Qe6 (2.363.730.117) 10125

34/53 5:18 +3.30++ 31.Qxd7 (3.264.332.799) 10239
Please, use the 2 best moves mode to compare the 2 eval.
Hi Vincent, is running. The difference is probably that McBrain, SugaR and Stockfish think a opp. bishop endgame is drawish, and Crafty 23.4 (not Houdini as I wrote first, at least that was not mentioned in the article) thinks with white passed pawns is not. A question of taste, if you do that :} (It is not always to say with certainty)

Typical last position I see in Shredder GUI for 31. Qxd7 in Multi PV:

[D]6k1/8/7p/8/R3PB2/7P/4bPPK/3r4 w - -
[pgn][Event "Mac Pro x5690 3.46 Ghz 18 CPU"]
[Site "Mac-Pro.local"]
[Date "2017.11.23"]
[Round "-"]
[White "SF-McBrain 4.0 64 POPCNT"]
[Black "Komodo 11.2.2 64-bit"]
[Result "1-0"]
[TimeControl "180+3"]
[FEN "r2r2q1/2Rn2bk/b2N2pp/pQ2p3/4Pp2/B4N1P/5PP1/2R3K1 w - - 2 1"]
[SetUp "1"]

1. Qa4 {+2.75/26 +174} Qe6 {-2.34/23 +174} 2. Kh2 {+3.04/23 +176} Nb6
{-2.93/26 +164} 3. Qxa5 {+3.08/30 +172} Nd7 {-3.20/27 +148} 4. R1c6
{+3.37/25 +174} Be2 {-2.57/27 +140} 5. Qb4 {+3.83/27 +174} Qa2
{-3.12/26 +132} 6. Nb7 {+4.04/27 +176} Bxf3 {-4.06/27 +128} 7. Bb2
{+4.21/29 +176} Bxg2 {-4.70/28 +114} 8. Kxg2 {+5.38/28 +175} f3+
{-3.78/27 +108} 9. Kh2 {+5.72/27 +176} Qb1 {-3.95/29 +105} 10. Rc1
{+7.26/28 +176} Qd3 {-4.29/29 +105} 11. Nxd8 {+8.85/29 +175} Rxd8
{-4.21/31 +103} 12. Qe7 {+10.09/27 +175} Qd2 {-7.08/30 +98} 13. Kg1
{+10.95/29 +175} Rg8 {-4.42/26 +96} 14. Rb1 {+11.87/28 +176} Qd3
{-8.86/31 +84} 15. Ra1 {+49.38/25 +174} Qd2 {-16.74/30 +44} 16. Bc3
{+132.70/40 +135} Qf4 {-250.00/33 +46} 17. Rxd7 {+1000.17/41 +104} Kh8
{-250.00/35 +49} 18. Bd2 {+1000.16/39 +102} Qf8 {-250.00/35 +50} 19. Qe6
{+1000.15/39 +101} Qe8 {-250.00/26 +52} 20. Qd5 {+1000.12/41 +93} Qb8
{-250.00/23 +54} 21. Raa7 {+1000.10/41 +92} Qb1+ {-1000.15/23 +57} 22. Kh2
{+1000.09/46 +92} Qb6 {-1000.08/27 +59} 23. Be3 {+1000.08/47 +91} Qf6
{-1000.07/29 +62} 24. Rf7 {+1000.07/48 +90} Rd8 {-1000.06/34 +64} 25. Qb7
{+1000.06/61 +90} Rg8 {-1000.05/48 +67} 26. Rxf6 {+1000.05/72 +89} Kh7
{-1000.04/99 +70} 27. Rf7 {+1000.04/111 +54} Kh8 {-1000.03/99 +72} 28. Rxg7
{+1000.03/127 +57} Re8 {-1000.02/99 +75} 29. Rh7+ {+1000.02/127 +60} Kg8
{-1000.01/5 +78} 30. Qg7# {+1000.01/127 +63}
{White mates} 1-0

[Event "Mac Pro x5690 3.46 Ghz 18 CPU"]
[Site "Mac-Pro.local"]
[Date "2017.11.23"]
[Round "-"]
[White "SF-McBrain 4.0 64 POPCNT"]
[Black "Komodo 11.2.2 64-bit"]
[Result "1-0"]
[TimeControl "180+3"]
[FEN "r2r2q1/2Rn2bk/b2N2pp/pQ2p3/4Pp2/B4N1P/5PP1/2R3K1 w - - 2 1"]
[SetUp "1"]

1. Qxd7 {+2.75/26 +183} Rxd7 {-1.32/22 +179} 2. Rxd7 {+2.76/25 +177} Rd8
{-2.90/27 +167} 3. Re7 {+3.42/26 +177} Qf8 {-2.90/28 +164} 4. Rcc7
{+3.55/25 +178} Rb8 {-4.32/28 +144} 5. Nxe5 {+4.79/25 +178} f3
{-4.22/26 +142} 6. Bb2 {+5.22/25 +179} Rxb2 {-4.36/28 +139} 7. Ne8
{+5.56/26 +180} Kg8 {-4.96/31 +130} 8. Rxg7+ {+5.83/26 +180} Qxg7
{-5.09/31 +128} 9. Rxg7+ {+6.08/26 +180} Kf8 {-5.10/32 +129} 10. Rxg6
{+6.27/26 +180} Rb1+ {-5.17/33 +123} 11. Kh2 {+6.25/1 +183} fxg2
{-6.48/32 +73} 12. Nc7 {+6.55/25 +184} g1=Q+ {-5.18/34 +66} 13. Rxg1
{+6.55/1 +187} Rxg1 {-5.34/34 +64} 14. Kxg1 {+7.20/27 +186} Be2
{-6.42/33 +54} 15. Ne6+ {+7.53/27 +186} Ke8 {-6.81/33 +53} 16. Nd4
{+7.94/29 +184} Ba6 {-7.26/33 +49} 17. Kg2 {+8.19/28 +184} a4
{-8.02/31 +46} 18. Nc2 {+8.94/31 +181} Kd8 {-10.61/32 +45} 19. Kf3
{+14.79/28 +167} Bc8 {-14.41/31 +41} 20. h4 {+15.01/21 +168} Kc7
{-15.13/30 +41} 21. Ke3 {+17.20/26 +167} Kd8 {-250.00/28 +43} 22. f4
{+23.75/26 +159} Ke8 {-250.00/31 +46} 23. f5 {+67.44/23 +157} Ba6
{-250.00/33 +47} 24. Kd4 {+132.68/28 +156} Ke7 {-250.00/30 +47} 25. Nc4
{+132.70/34 +156} Kf8 {-250.00/31 +49} 26. e5 {+1000.17/33 +156} a3
{-250.00/28 +49} 27. N2xa3 {+1000.14/41 +153} Bb7 {-250.00/28 +51} 28. e6
{+1000.11/48 +152} Kg7 {-250.00/26 +53} 29. Ke5 {+1000.10/52 +148} Bf3
{-1000.09/26 +56} 30. Nd6 {+1000.09/55 +146} Bg4 {-1000.08/29 +58} 31. e7
{+1000.08/58 +144} Bh5 {-1000.07/37 +61} 32. Ke6 {+1000.07/67 +142} Kg8
{-1000.06/60 +63} 33. Kf6 {+1000.06/97 +141} Kh8 {-1000.05/99 +66} 34. Nf7+
{+1000.05/124 +140} Bxf7 {-1000.04/99 +69} 35. Kxf7 {+1000.04/127 +143} Kh7
{-1000.03/99 +72} 36. e8=Q {+1000.03/127 +146} h5 {-1000.02/5 +75} 37. f6
{+1000.02/127 +149} Kh6 {-1000.01/5 +78} 38. Qh8# {+1000.01/127 +152}
{White mates} 1-0

[/pgn]

Qa4 looks to be slightly stronger, Qxd7 is the daring move thatfolsk love to see play.

Uri Blass
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Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by Uri Blass » Fri Nov 24, 2017 4:44 am

Eelco de Groot wrote:
Vinvin wrote:
Eelco de Groot wrote:
34/25 3:53 +3.22-- 31.Qa4 Qe6 (2.363.730.117) 10125

34/53 5:18 +3.30++ 31.Qxd7 (3.264.332.799) 10239
Please, use the 2 best moves mode to compare the 2 eval.
Hi Vincent, is running. The difference is probably that McBrain, SugaR and Stockfish think a opp. bishop endgame is drawish, and Crafty 23.4 (not Houdini as I wrote first, at least that was not mentioned in the article) thinks with white passed pawns is not. A question of taste, if you do that :} (It is not always to say with certainty)

Typical last position I see in Shredder GUI for 31. Qxd7 in Multi PV:

[D]6k1/8/7p/8/R3PB2/7P/4bPPK/3r4 w - -
I do not understand why do you trust the position that you see in shredder GUI in multi-pv

It is known that programs do not find the best move in long pv.


[D]6q1/2R1R1bk/6pp/p3B3/4Pp2/7P/4bPPK/3r4 w - - 3 38

It seems that in this position you assume that white play Rxg7+ instead of 38.Bf6

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Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by Dann Corbit » Fri Nov 24, 2017 4:45 am

Both win
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Eelco de Groot
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Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by Eelco de Groot » Fri Nov 24, 2017 5:42 am

I don't quite understand Uri, if Bf6 is better, White is more winning. But it is a waiting move, and after h5, planning Kh6 I think it still has to be Rxg7? I agree it is a nice move from a human point of view and that Stockfish thinks h5 weakens the position probably at least in KS calculations, and that Stockfish probably would not find the move it unless you first show it because it is Zugzwang for Black.

After showing Kaissa Bf6:

[D]6q1/2R1R1bk/6pp/p3B3/4Pp2/7P/4bPPK/3r4 w - -

Engine: Kaissa HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

33 9:20 +5.97 38.Bf6 h5 39.Rxg7+ Qxg7 40.Rxg7+ Kh6
41.h4 Rd6 42.Rf7 Rxf6 43.Rxf6 a4
44.Rf7 a3 45.Ra7 a2 46.Rxa2 Bb5
47.e5 Kg7 48.Ra5 Be8 49.Ra6 Kf7
50.Rf6+ Ke7 51.f3 (3.404.519.023) 6077

33 9:20 +4.98 38.Rxg7+ Qxg7 39.Rxg7+ Kh8 40.Rxg6+ Kh7
41.Rg7+ Kh8 42.Ra7+ Kg8 43.Bxf4 Rd4
44.f3 Ra4 45.Bxh6 Ra2 46.Kg1 Bb5
47.Rg7+ Kh8 48.Rb7 Bc6 49.Ra7 a4
50.h4 Ra1+ 51.Kf2 (3.404.519.023) 6077

33 9:20 +4.98 38.f3 a4 39.Rxg7+ Qxg7 40.Rxg7+ Kh8
41.Rxg6+ Kh7 42.Rg7+ Kh8 43.Ra7+ Kg8
44.Rxa4 Rb1 45.Bxf4 Rb2 46.Kg1 Rb6
47.Be3 Rb1+ 48.Kf2 Bb5 49.Ra8+ Kg7
50.Rb8 h5 51.Kg3 (3.404.519.023) 6077

32 9:20 +3.99 38.Rb7 h5 39.Rxg7+ Qxg7 40.Rxg7+ Kh8
41.f3 a4 42.h4 Re1 43.Rxg6+ Kh7
44.Rg5 Bf1 45.Bxf4 a3 46.Rxh5+ Kg8
47.Ra5 Re2 48.Kg1 Bxg2 49.Rxa3 Bh3
50.Ra8+ Kh7 51.Ra7+ (3.404.519.023) 6077
Last edited by Eelco de Groot on Fri Nov 24, 2017 5:57 am, edited 2 times in total.
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tpoppins
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Re: Piket vs Smirin 1993 : CB claims 31.Qxd7 is better than

Post by tpoppins » Fri Nov 24, 2017 5:50 am

H6.03 Pro needs d=38 to prefer 31.Qxd7.

Code: Select all

Piket--Smirin, Biel 1993
r2r2q1/2Rn2bk/b2N2pp/pQ2p3/4Pp2/B4N1P/5PP1/2R3K1 w - - 2 31

Analysis by Houdini 6.03 Pro x64-popcnt (15 cores, Tactical=5, 8GB hash)

1. +- (3.50): 31.Qxd7 Rxd7 32.Rxd7 Be2 33.Rcc7 Bxf3 34.Bb2 Rd8 35.Re7 Rxd6 36.Bxe5 Rd1+ 37.Kh2 Be2 38.Rxg7+ Qxg7 39.Rxg7+ Kh8 40.Rxg6+ Kh7 41.Rg7+ Kh8 42.f3 a4 43.Ra7+ Kg8 44.Ra8+ Kf7 45.Rxa4 Rb1 46.Ra7+ Ke8 47.Bxf4 Rb6 48.h4 Ra6 49.Rh7 Kf8 50.Kg3 Kg8 51.Rd7 Bb5 52.Rc7 Be8 53.Kg4 Ra2 54.g3 Ra6 55.Be5 Bb5 56.Kf5 Rc6 57.Rb7 Ba6 58.Ra7 Kf8 59.g4 Ke8 60.g5 
2. +- (3.31): 31.Qa4 Qe6 32.Kh2 Nb6 33.Qxa5 Rxd6 34.Bxd6 Qxd6 35.R1c6 Nc4 36.Rxd6 Nxa5 37.Nxe5 Rc8 38.Rxg7+ Kxg7 39.Rxg6+ Kh7 40.Rxa6 Nb3 41.Ng4 Nd2 42.Nf6+ Kg6 43.h4 f3 44.Nd5+ Kg7 45.Ra7+ Kf8 46.gxf3 Nxf3+ 47.Kg3 Nd4 48.f4 Re8 49.e5 Re6 50.Kg4 Nc6 51.Rh7 Kg8 52.Rc7 Kf8 53.Nf6 Ne7 54.Ra7 Rc6 55.Ne4 Rc4 56.Nd6 Rc2 57.f5 
Depth: 38/89   02:47:46  293164 MN, tb=25245253
The bottom line is:
carldaman wrote:The move played was certainly brilliant but it was not the only winning move, and not necessarily the most accurate, though that hardly matters here. It certainly wasn't risk-free.

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