White to play and win

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David Dahlem
Posts: 900
Joined: Wed Mar 08, 2006 9:06 pm

White to play and win

Post by David Dahlem »

[Event "ChessCafe Endgame Study"]
[Site "?"]
[Date "1997.08.08"]
[Round "?"]
[White "White to Play and Win"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/8/7k/p1N5/7P/2p5/1P2K3/3B2b1 w - - 0 1"]
[PlyCount "21"]
[EventDate "2005.??.??"]

{T. Gorgiev. "Shakhmaty v SSSR" 1936. 2nd Prize} 1. b4 axb4 2. Nd3 c2 3. Bxc2 Kh5 4. Ne1 Bc5 5. Ng2 Be7 6. Bd1 Bxh4 7. Ke3+ Kg5 8. Kf3 b3 9. Bxb3 Kh5 10. Bf7+ Kg5 11. Be8 {and wins. Usually bishops of opposite colors increase the weaker side's drawing chances. However, here White is able to take advantage of this situation.} 1-0

[d]8/8/7k/p1N5/7P/2p5/1P2K3/3B2b1 w - - 0 1

With best play by black, i'm not sure white can win. Any engines show a win from this position?
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royb
Posts: 565
Joined: Thu Mar 09, 2006 12:53 am

Re: White to play and win

Post by royb »

It seems Stockfish 1.6.3 (1 core) thinks there is a sizable advantage to be gained by White:

.
.
.

23 +1.65 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Kf5 15.Bc4 Bc5 16.Ka2 Bb4 17.Bf7 Kg5 18.Bg6 Kf6 19.Be8 Kg5 20.Bf7 Bc5 21.Bg6 (9.42)
24 +0.84 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Bf8 15.Ka2 Bb4 (11.92)
25 +0.64 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Bc5 15.Bf3 Bf8 16.Nd2 Kf4 17.Ka2 Ke3 (17.43)
26 +0.40 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Kh6 15.Bc4 a2 16.Kxa2 Kxh5 17.Bd5 Kg5 18.Kb3 Be7 19.Kc2 Kf5 (38.62)
26 +0.48 1.bxc3 Bxc5 2.Kd3 a4 3.c4 Bf2 4.h5 a3 5.Kc2 Kg5 6.Kb3 Bc5 7.Ka2 Kf5 8.Ba4 Kg5 9.Be8 Kh6 10.Bf7 Kg5 11.Bg6 Kh6 12.Be8 Kg5 13.Kb3 Kh6 14.Bg6 Kg5 15.Bf7 Kh6 16.Be8 Kg5 17.Bg6 Kh6 18.Ka2 Kg5 19.Kb1 Bd4 20.Ka2 Bc5 (47.36)
26 +0.52 1.b4 axb4 2.Nd3 c2 3.Bxc2 Kh5 4.Ne5 Bh2 5.Nf3 Bg3 6.Bb3 Bxh4 7.Kd3 Kg4 8.Ke4 Bf6 9.Nd2 Kg3 10.Nc4 Kf2 11.Kd3 Kf3 12.Nb6 Bc3 13.Nd5 Be5 14.Bd1+ Kf2 15.Bb3 (71.57)
27 +1.37 1.b4 c2 2.Bxc2 axb4 3.Nd3 Kh5 4.Ne1 Bb6 5.Ng2 Bd8 6.Bd1 Bxh4 7.Ke3+ Kg5 8.Kf3 b3 9.Bxb3 Kh5 10.Bf7+ Kg5 11.Be8 (106.75)
28 +2.46 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Bf8 9.Ne3 Kg7 10.Kg5 Kh7 11.Nf5 Bc5 12.Kf4 Bf8 13.Bc2 Bh6+ 14.Ke4 Bf8 15.Ke3 Bh6+ 16.Kd3 Bf4 (206.82)
29 +2.62 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Kg7 9.Bc2 Bd6 10.Kg5 Bc5 11.h6+ Kh8 12.Kg6 Bd6 13.Nf6 Bf4 14.Ng4 Kg8 15.Kf5 Bd2 16.Ke5 Kf7 17.Kd4 (291.46)
30 +2.78 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Kg7 9.Bc2 Bd6 10.Kg5 Bc5 11.Bb3 Kh8 12.Kg6 Bd6 13.Ne3 Bc5 14.Ng4 Bd4 15.Kg5 Kg7 16.Kf5 Kh7 17.Bc2 Bc5 18.Ke5+ Kg8 19.h6 Kh8 20.Nf6 Bf8 (331.53)
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zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: White to play and win

Post by zullil »

royb wrote:It seems Stockfish 1.6.3 (1 core) thinks there is a sizable advantage to be gained by White:

.
.
.

23 +1.65 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Kf5 15.Bc4 Bc5 16.Ka2 Bb4 17.Bf7 Kg5 18.Bg6 Kf6 19.Be8 Kg5 20.Bf7 Bc5 21.Bg6 (9.42)
24 +0.84 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Bf8 15.Ka2 Bb4 (11.92)
25 +0.64 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Bc5 15.Bf3 Bf8 16.Nd2 Kf4 17.Ka2 Ke3 (17.43)
26 +0.40 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Kh6 15.Bc4 a2 16.Kxa2 Kxh5 17.Bd5 Kg5 18.Kb3 Be7 19.Kc2 Kf5 (38.62)
26 +0.48 1.bxc3 Bxc5 2.Kd3 a4 3.c4 Bf2 4.h5 a3 5.Kc2 Kg5 6.Kb3 Bc5 7.Ka2 Kf5 8.Ba4 Kg5 9.Be8 Kh6 10.Bf7 Kg5 11.Bg6 Kh6 12.Be8 Kg5 13.Kb3 Kh6 14.Bg6 Kg5 15.Bf7 Kh6 16.Be8 Kg5 17.Bg6 Kh6 18.Ka2 Kg5 19.Kb1 Bd4 20.Ka2 Bc5 (47.36)
26 +0.52 1.b4 axb4 2.Nd3 c2 3.Bxc2 Kh5 4.Ne5 Bh2 5.Nf3 Bg3 6.Bb3 Bxh4 7.Kd3 Kg4 8.Ke4 Bf6 9.Nd2 Kg3 10.Nc4 Kf2 11.Kd3 Kf3 12.Nb6 Bc3 13.Nd5 Be5 14.Bd1+ Kf2 15.Bb3 (71.57)
27 +1.37 1.b4 c2 2.Bxc2 axb4 3.Nd3 Kh5 4.Ne1 Bb6 5.Ng2 Bd8 6.Bd1 Bxh4 7.Ke3+ Kg5 8.Kf3 b3 9.Bxb3 Kh5 10.Bf7+ Kg5 11.Be8 (106.75)
28 +2.46 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Bf8 9.Ne3 Kg7 10.Kg5 Kh7 11.Nf5 Bc5 12.Kf4 Bf8 13.Bc2 Bh6+ 14.Ke4 Bf8 15.Ke3 Bh6+ 16.Kd3 Bf4 (206.82)
29 +2.62 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Kg7 9.Bc2 Bd6 10.Kg5 Bc5 11.h6+ Kh8 12.Kg6 Bd6 13.Nf6 Bf4 14.Ng4 Kg8 15.Kf5 Bd2 16.Ke5 Kf7 17.Kd4 (291.46)
30 +2.78 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Kg7 9.Bc2 Bd6 10.Kg5 Bc5 11.Bb3 Kh8 12.Kg6 Bd6 13.Ne3 Bc5 14.Ng4 Bd4 15.Kg5 Kg7 16.Kf5 Kh7 17.Bc2 Bc5 18.Ke5+ Kg8 19.h6 Kh8 20.Nf6 Bf8 (331.53)
Here's what Stockfish-1.6.3 (8 threads) says through depth 40:

Code: Select all

Searching: 8/8/7k/p1N5/7P/2p5/1P2K3/3B2b1 w - -
infinite: 1 ponder: 0 time: 0 increment: 0 moves to go: 0
 2     +3.03   00:01       97 Nd3 cxb2 Nxb2 
 3     +2.59   00:01      275 Nd3 cxb2 Nxb2 Bd4 
 4     +3.27   00:01      532 Nd3 cxb2 Nxb2 Bd4 Nc4 
 5     +3.39   00:01     1140 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 
 6  <  +2.46   00:01     1731 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 
 7     +0.69   00:01     5164 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 
 7     +1.45   00:01    11274 b4 axb4 Ne4 Kg6 Kd3 Kf5 Bc2 
 8     +0.61   00:01    35080 b4 axb4 Ne4 c2 Bxc2 Kh5 Bb3 Kxh4 Kd3 Kh5 Kc4 Kg4 
 8     +0.69   00:01    36137 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bf3 
 9     +0.61   00:01    56132 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bf3 Bf6 Bd5 
                              Kg5 
 9     +0.69   00:01    64026 b4 axb4 Nd7 Bd4 Kd3 b3 Bxb3 Bf2 Kc2 Bxh4 
10     +0.57   00:01   168603 b4 axb4 Nd7 Bd4 Kf3 Bg7 Ke4 b3 Bxb3 Kh5 Bd1+ Kxh4 
                              Bc2 
10     +0.65   00:01   171711 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bf3 a4 Bd5 
11     +0.57   00:01   220704 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bc2 Bf6 Ba4 
                              Kg5 Ke4 Bc3 Bd7 
11  >  +0.85   00:01   247568 Ne4 cxb2 Nd2 a4 Kd3 Bf2 h5 a3 Kc2 Bc5 Nc4 
12     +1.54   00:01   390595 Ne4 cxb2 Nd2 a4 Kd3 Bf2 h5 Be1 Nb1 Bb4 Kc2 a3 Kb3 
                              Bc5 Ka2 Kg5 Be2 Kf5 Bf3 Kf4 Bd5 Kg5 
13     +1.33   00:01   558847 Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Kg6 
                              h5+ Kf5 Ka2 Ke4 h6 
14     +1.54   00:01   818007 Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Kg6 
                              h5+ Kf5 Ka2 Kg5 Bf3 Be7 Nd2 Kf4 h6 
15     +1.41   00:01    1021k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bc4 Ke3 Be6 Ke4 Nxa3 
16     +1.49   00:01    1427k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
17     +1.49   00:01    2095k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
18     +1.49   00:01    2992k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
19     +1.41   00:01    4276k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
                              Ke4 Nxa3 Bxa3 
20  <  +1.21   00:02    5712k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Kh6 Kb3 Kg5 Ka2 
21     +1.49   00:02    8387k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Kh6 Kb3 Kg5 Be2 Bf8 Ka2 Bb4 Bd1 
                              Kf5 Nxa3 Bxa3 
22     +0.40   00:03   18747k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Bb4 Ka2 Kg5 Bf3 Kh6 Be2 Kg5 Bf3 
22     +0.53   00:05   41727k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne5 Bb6 Nf3 Bd8 Bb3 Bxh4 
                              Kd3 Kg4 Ke4 Bf6 Ne1 Bh4 Nd3 Bg3 Kd5 Kf5 Kd4 Bf4 
23     +0.53   00:06   54967k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne5 Bb6 Nf3 Bd8 Bb3 Bxh4 
                              Kd3 Kg4 Ke4 Bf6 Ne1 Bh4 Nd3 Bg3 Kd5 Kf5 Kd4 Bf4 
24     +0.53   00:08   74517k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne5 Bb6 Nf3 Bd8 Bb3 Bxh4 
                              Kd3 Kg4 Ke4 Bf6 Ne1 Bh4 Nd3 Bg3 Kd5 Kf5 Kd4 Bf4 
                              Nc5 Kg5 Kd3 
25  >  +0.73   00:12  112839k b4 c2 Bxc2 axb4 Nd3 Kh5 Ne1 Bc5 Ng2 Be7 Bd1 Bxh4 
                              Ke3+ Kg5 Kf3 b3 Bxb3 Kh5 Bf7+ Kg5 Be8 
26  >  +1.54   00:13  123415k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne1 Bc5 Ng2 Be7 Bd1 Bxh4 
                              Ke3+ Kg5 Kf3 b3 Bxb3 Kh5 Bf7+ Kg5 Be8 
27     +2.06   00:44  472827k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Kc2 Bd8 h5 Bg5 Ne1 Be7 Nd3 Kg5 Ne5 Bf8 Bf3 Bg7 
                              Nd3 Bf8 Be2 Bd6 Bf3 Kf5 Bd1 Kf6 Nf2 Bf8 Ng4+ Kg5 
                              Ne5 Kf5 Nc6 Bd6 Nd4+ Kf6 Bg4 Bf8 Bf5 Bc5 Ne6 Ba7 
28     +2.51   00:54  565775k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Bd1+ Kh6 Kg4 Kg6 h5+ Kf6 
                              Bb3 Ke5 h6 Kf6 Kh5 Bf8 Bc2 b3 Bxb3 Bd6 Bc2 
29     +2.59   01:06  673881k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Bd1+ Kh6 Kg4 Kg6 Nf4+ Kf6 
                              Nd5+ Kf7 h5 Bf8 Bb3 Kg7 Kg5 Bd6 Bc2 Bc5 h6+ Kh8 
                              Kg6 Bd6 Kf6 Bf8 Kf5 Bxh6 Nxb4 Kg7 
30     +2.59   01:18  781721k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Bd1+ Kh6 Kg4 Kg6 Nf4+ Kf6 
                              Nd5+ Kf7 h5 Bf8 Bb3 Kg7 Kg5 Bd6 Bc2 Bc5 h6+ Kh8 
                              Kg6 Bd6 Kf6 Bf8 Kf5 Bxh6 Nxb4 Kg7 
31     +2.51   01:44    1011M b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Nf4+ Kh6 Kg4 Kg7 Nd5 Bd6 
                              Kg5 Kf7 Bb3 Kg7 h5 Bc5 h6+ Kh7 Nf6+ Kh8 Kf4 Bd6+ 
                              Ke4 Bf8 Ng8 
32  >  +2.71   02:16    1307M b4 c2 Bxc2 axb4 Nd3 Kh5 Ne1 Bd4 Bd1 Bf6 Ng2 Bxh4 
                              Ke3+ Kg5 Kf3 b3 Bxb3 Kh5 Bf7+ Kg5 Be8 
33  >  +3.60   03:23    1931M b4 axb4 Nd3 Ba7 Nf4 Bb8 Kf3 Kg7 Nd5 Bd6 h5 Bf8 
                              Kg4 Kh6 Ba4 Kg7 Bc2 Bd6 Kg5 Bc5 Kf4 Kh6 Kg4 Kg7 
                              Kg5 Kh8 Kg6 Bd6 Kf5 Bc5 Kf4 Bf8 Kf3 Kg7 Kg4 
34     +3.56   05:02    2787M b4 axb4 Nd3 Ba7 Nf4 Bb8 Kf3 Kg7 Nd5 Bd6 h5 Bf8 
                              Kg4 Kh6 Ba4 Kg7 Bc2 Bd6 Kg5 Bc5 Kf4 Kh6 Kg4 Kg7 
                              Kg5 Kh8 Bd1 Bf8 Kf5 Bc5 Nf6 Be7 Ng4 Kg7 Ne5 c2 
                              Bxc2 Kh6 Bd1 Bc5 Ke6 Kg7 Nd3 Bf8 
35     +3.15   10:29    5899M b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Kd3 Kg6 Ke4 Kf6 
                              Ne3 Kg6 Bc2 Bb8 Ng2 Kh6 Kf5 Bd6 Kg4 Kg7 h5 Bf8 
                              Nf4 Kf6 Bb3 Bh6 Nd5+ Ke5 Nxb4 Ke4 Bc2+ Ke3 Kf5 
                              Bf8 Nc6 Kd2 Bb1 Bh6 Nd4 Kc1 Bd3 Kd2 Ke4 Kd1 Nc2 
                              Kd2 
36     +3.64   16:39    9199M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Ke5 Ke2 Bg5 Kd3 Bd2 
                              Be8 Kf6 Nd4 Ke7 Bc6 Kf6 
37     +3.64   38:53   22205M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Bh6 Ke4 Kg5 Kd3 Bg7 
                              Bf7 Kh6 Nb4 Be5 Nc6 Bf6 Kc2 
38     +4.04   51:26   28878M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Bh6 Ke4 Kg5 Kd3 Bg7 
                              Bf7 Kh6 Nb4 Be5 Nd5 Kg7 Bg6 Kh6 Nxc3 
39     +4.08 1:05:49   36695M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Bh6 Ke4 Kg5 Kd3 Bg7 
                              Ne3 Be5 Nc4 Bg7 Nd6 Kf4 Ne4 c2 Kxc2 Bd4 
40     +4.08 2:01:23   68145M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Bd2 
                              Nd3+ Kf6 Bd1 Kg7 Kf5 Kh6 Nb4 Kg7 Nc2 Kh6 Ke4 Kg5 
                              Nb4 Kf6 Nd5+ Kg5 Kd3 Kf5 Nb4 Kg5 Bf3 Kf6 Nd5+ Kf5 
                              Kc2 Kg5 Nxc3 
Nodes: 68463550436
Nodes/second: 9347080
Best move: b4
Ponder move: axb4
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User avatar
Eelco de Groot
Posts: 4663
Joined: Sun Mar 12, 2006 2:40 am
Full name:   Eelco de Groot

Re: White to play and win

Post by Eelco de Groot »

zullil wrote:
royb wrote:It seems Stockfish 1.6.3 (1 core) thinks there is a sizable advantage to be gained by White:

.
.
.

23 +1.65 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Kf5 15.Bc4 Bc5 16.Ka2 Bb4 17.Bf7 Kg5 18.Bg6 Kf6 19.Be8 Kg5 20.Bf7 Bc5 21.Bg6 (9.42)
24 +0.84 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Bf8 15.Ka2 Bb4 (11.92)
25 +0.64 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Bc5 15.Bf3 Bf8 16.Nd2 Kf4 17.Ka2 Ke3 (17.43)
26 +0.40 1.Ne4 cxb2 2.Nd2 Bc5 3.Kd3 Bb4 4.Nb1 a4 5.Kc2 a3 6.Kb3 Be7 7.h5 Bf8 8.Ka2 Bb4 9.Bg4 Kg5 10.Be2 Kh6 11.Bd1 Kg5 12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 Kh6 15.Bc4 a2 16.Kxa2 Kxh5 17.Bd5 Kg5 18.Kb3 Be7 19.Kc2 Kf5 (38.62)
26 +0.48 1.bxc3 Bxc5 2.Kd3 a4 3.c4 Bf2 4.h5 a3 5.Kc2 Kg5 6.Kb3 Bc5 7.Ka2 Kf5 8.Ba4 Kg5 9.Be8 Kh6 10.Bf7 Kg5 11.Bg6 Kh6 12.Be8 Kg5 13.Kb3 Kh6 14.Bg6 Kg5 15.Bf7 Kh6 16.Be8 Kg5 17.Bg6 Kh6 18.Ka2 Kg5 19.Kb1 Bd4 20.Ka2 Bc5 (47.36)
26 +0.52 1.b4 axb4 2.Nd3 c2 3.Bxc2 Kh5 4.Ne5 Bh2 5.Nf3 Bg3 6.Bb3 Bxh4 7.Kd3 Kg4 8.Ke4 Bf6 9.Nd2 Kg3 10.Nc4 Kf2 11.Kd3 Kf3 12.Nb6 Bc3 13.Nd5 Be5 14.Bd1+ Kf2 15.Bb3 (71.57)
27 +1.37 1.b4 c2 2.Bxc2 axb4 3.Nd3 Kh5 4.Ne1 Bb6 5.Ng2 Bd8 6.Bd1 Bxh4 7.Ke3+ Kg5 8.Kf3 b3 9.Bxb3 Kh5 10.Bf7+ Kg5 11.Be8 (106.75)
28 +2.46 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Bf8 9.Ne3 Kg7 10.Kg5 Kh7 11.Nf5 Bc5 12.Kf4 Bf8 13.Bc2 Bh6+ 14.Ke4 Bf8 15.Ke3 Bh6+ 16.Kd3 Bf4 (206.82)
29 +2.62 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Kg7 9.Bc2 Bd6 10.Kg5 Bc5 11.h6+ Kh8 12.Kg6 Bd6 13.Nf6 Bf4 14.Ng4 Kg8 15.Kf5 Bd2 16.Ke5 Kf7 17.Kd4 (291.46)
30 +2.78 1.b4 axb4 2.Nd3 Bd4 3.Kf3 Bf6 4.Kg4 Be7 5.Nf4 Bd6 6.Nd5 Bf8 7.h5 Bc5 8.Bb3 Kg7 9.Bc2 Bd6 10.Kg5 Bc5 11.Bb3 Kh8 12.Kg6 Bd6 13.Ne3 Bc5 14.Ng4 Bd4 15.Kg5 Kg7 16.Kf5 Kh7 17.Bc2 Bc5 18.Ke5+ Kg8 19.h6 Kh8 20.Nf6 Bf8 (331.53)
Here's what Stockfish-1.6.3 (8 threads) says through depth 40:

Code: Select all

Searching: 8/8/7k/p1N5/7P/2p5/1P2K3/3B2b1 w - -
infinite: 1 ponder: 0 time: 0 increment: 0 moves to go: 0
 2     +3.03   00:01       97 Nd3 cxb2 Nxb2 
 3     +2.59   00:01      275 Nd3 cxb2 Nxb2 Bd4 
 4     +3.27   00:01      532 Nd3 cxb2 Nxb2 Bd4 Nc4 
 5     +3.39   00:01     1140 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 
 6  <  +2.46   00:01     1731 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 
 7     +0.69   00:01     5164 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 
 7     +1.45   00:01    11274 b4 axb4 Ne4 Kg6 Kd3 Kf5 Bc2 
 8     +0.61   00:01    35080 b4 axb4 Ne4 c2 Bxc2 Kh5 Bb3 Kxh4 Kd3 Kh5 Kc4 Kg4 
 8     +0.69   00:01    36137 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bf3 
 9     +0.61   00:01    56132 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bf3 Bf6 Bd5 
                              Kg5 
 9     +0.69   00:01    64026 b4 axb4 Nd7 Bd4 Kd3 b3 Bxb3 Bf2 Kc2 Bxh4 
10     +0.57   00:01   168603 b4 axb4 Nd7 Bd4 Kf3 Bg7 Ke4 b3 Bxb3 Kh5 Bd1+ Kxh4 
                              Bc2 
10     +0.65   00:01   171711 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bf3 a4 Bd5 
11     +0.57   00:01   220704 Nd3 cxb2 Nxb2 Bd4 Nc4 Bf6 Kd3 Bxh4 Bc2 Bf6 Ba4 
                              Kg5 Ke4 Bc3 Bd7 
11  >  +0.85   00:01   247568 Ne4 cxb2 Nd2 a4 Kd3 Bf2 h5 a3 Kc2 Bc5 Nc4 
12     +1.54   00:01   390595 Ne4 cxb2 Nd2 a4 Kd3 Bf2 h5 Be1 Nb1 Bb4 Kc2 a3 Kb3 
                              Bc5 Ka2 Kg5 Be2 Kf5 Bf3 Kf4 Bd5 Kg5 
13     +1.33   00:01   558847 Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Kg6 
                              h5+ Kf5 Ka2 Ke4 h6 
14     +1.54   00:01   818007 Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Kg6 
                              h5+ Kf5 Ka2 Kg5 Bf3 Be7 Nd2 Kf4 h6 
15     +1.41   00:01    1021k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bc4 Ke3 Be6 Ke4 Nxa3 
16     +1.49   00:01    1427k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
17     +1.49   00:01    2095k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
18     +1.49   00:01    2992k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
19     +1.41   00:01    4276k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Bf8 Be2 Kf4 Bd3 Ke3 Bf5 Kf4 Be6 
                              Ke4 Nxa3 Bxa3 
20  <  +1.21   00:02    5712k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Kh6 Kb3 Kg5 Ka2 
21     +1.49   00:02    8387k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Kg5 Ka2 Bb4 Bf3 Kh6 Kb3 Kg5 Be2 Bf8 Ka2 Bb4 Bd1 
                              Kf5 Nxa3 Bxa3 
22     +0.40   00:03   18747k Ne4 cxb2 Nd2 Bc5 Kd3 Bb4 Nb1 a4 Kc2 a3 Kb3 Be7 h5 
                              Bb4 Ka2 Kg5 Bf3 Kh6 Be2 Kg5 Bf3 
22     +0.53   00:05   41727k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne5 Bb6 Nf3 Bd8 Bb3 Bxh4 
                              Kd3 Kg4 Ke4 Bf6 Ne1 Bh4 Nd3 Bg3 Kd5 Kf5 Kd4 Bf4 
23     +0.53   00:06   54967k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne5 Bb6 Nf3 Bd8 Bb3 Bxh4 
                              Kd3 Kg4 Ke4 Bf6 Ne1 Bh4 Nd3 Bg3 Kd5 Kf5 Kd4 Bf4 
24     +0.53   00:08   74517k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne5 Bb6 Nf3 Bd8 Bb3 Bxh4 
                              Kd3 Kg4 Ke4 Bf6 Ne1 Bh4 Nd3 Bg3 Kd5 Kf5 Kd4 Bf4 
                              Nc5 Kg5 Kd3 
25  >  +0.73   00:12  112839k b4 c2 Bxc2 axb4 Nd3 Kh5 Ne1 Bc5 Ng2 Be7 Bd1 Bxh4 
                              Ke3+ Kg5 Kf3 b3 Bxb3 Kh5 Bf7+ Kg5 Be8 
26  >  +1.54   00:13  123415k b4 axb4 Nd3 c2 Bxc2 Kh5 Ne1 Bc5 Ng2 Be7 Bd1 Bxh4 
                              Ke3+ Kg5 Kf3 b3 Bxb3 Kh5 Bf7+ Kg5 Be8 
27     +2.06   00:44  472827k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Kc2 Bd8 h5 Bg5 Ne1 Be7 Nd3 Kg5 Ne5 Bf8 Bf3 Bg7 
                              Nd3 Bf8 Be2 Bd6 Bf3 Kf5 Bd1 Kf6 Nf2 Bf8 Ng4+ Kg5 
                              Ne5 Kf5 Nc6 Bd6 Nd4+ Kf6 Bg4 Bf8 Bf5 Bc5 Ne6 Ba7 
28     +2.51   00:54  565775k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Bd1+ Kh6 Kg4 Kg6 h5+ Kf6 
                              Bb3 Ke5 h6 Kf6 Kh5 Bf8 Bc2 b3 Bxb3 Bd6 Bc2 
29     +2.59   01:06  673881k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Bd1+ Kh6 Kg4 Kg6 Nf4+ Kf6 
                              Nd5+ Kf7 h5 Bf8 Bb3 Kg7 Kg5 Bd6 Bc2 Bc5 h6+ Kh8 
                              Kg6 Bd6 Kf6 Bf8 Kf5 Bxh6 Nxb4 Kg7 
30     +2.59   01:18  781721k b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Bd1+ Kh6 Kg4 Kg6 Nf4+ Kf6 
                              Nd5+ Kf7 h5 Bf8 Bb3 Kg7 Kg5 Bd6 Bc2 Bc5 h6+ Kh8 
                              Kg6 Bd6 Kf6 Bf8 Kf5 Bxh6 Nxb4 Kg7 
31     +2.51   01:44    1011M b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Ke3 Bc5+ Kd3 Be7 
                              Ke4 Kg6 Bc2 Kh6 Kf5 Kh5 Nf4+ Kh6 Kg4 Kg7 Nd5 Bd6 
                              Kg5 Kf7 Bb3 Kg7 h5 Bc5 h6+ Kh7 Nf6+ Kh8 Kf4 Bd6+ 
                              Ke4 Bf8 Ng8 
32  >  +2.71   02:16    1307M b4 c2 Bxc2 axb4 Nd3 Kh5 Ne1 Bd4 Bd1 Bf6 Ng2 Bxh4 
                              Ke3+ Kg5 Kf3 b3 Bxb3 Kh5 Bf7+ Kg5 Be8 
33  >  +3.60   03:23    1931M b4 axb4 Nd3 Ba7 Nf4 Bb8 Kf3 Kg7 Nd5 Bd6 h5 Bf8 
                              Kg4 Kh6 Ba4 Kg7 Bc2 Bd6 Kg5 Bc5 Kf4 Kh6 Kg4 Kg7 
                              Kg5 Kh8 Kg6 Bd6 Kf5 Bc5 Kf4 Bf8 Kf3 Kg7 Kg4 
34     +3.56   05:02    2787M b4 axb4 Nd3 Ba7 Nf4 Bb8 Kf3 Kg7 Nd5 Bd6 h5 Bf8 
                              Kg4 Kh6 Ba4 Kg7 Bc2 Bd6 Kg5 Bc5 Kf4 Kh6 Kg4 Kg7 
                              Kg5 Kh8 Bd1 Bf8 Kf5 Bc5 Nf6 Be7 Ng4 Kg7 Ne5 c2 
                              Bxc2 Kh6 Bd1 Bc5 Ke6 Kg7 Nd3 Bf8 
35     +3.15   10:29    5899M b4 axb4 Nd3 Ba7 Nf4 Bb8 Ng2 Bd6 Kd3 Kg6 Ke4 Kf6 
                              Ne3 Kg6 Bc2 Bb8 Ng2 Kh6 Kf5 Bd6 Kg4 Kg7 h5 Bf8 
                              Nf4 Kf6 Bb3 Bh6 Nd5+ Ke5 Nxb4 Ke4 Bc2+ Ke3 Kf5 
                              Bf8 Nc6 Kd2 Bb1 Bh6 Nd4 Kc1 Bd3 Kd2 Ke4 Kd1 Nc2 
                              Kd2 
36     +3.64   16:39    9199M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Ke5 Ke2 Bg5 Kd3 Bd2 
                              Be8 Kf6 Nd4 Ke7 Bc6 Kf6 
37     +3.64   38:53   22205M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Bh6 Ke4 Kg5 Kd3 Bg7 
                              Bf7 Kh6 Nb4 Be5 Nc6 Bf6 Kc2 
38     +4.04   51:26   28878M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Bh6 Ke4 Kg5 Kd3 Bg7 
                              Bf7 Kh6 Nb4 Be5 Nd5 Kg7 Bg6 Kh6 Nxc3 
39     +4.08 1:05:49   36695M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Ke4 
                              Nc2 Bc1 Bf7 Ke5 Kf3 Kf6 Bg6 Bh6 Ke4 Kg5 Kd3 Bg7 
                              Ne3 Be5 Nc4 Bg7 Nd6 Kf4 Ne4 c2 Kxc2 Bd4 
40     +4.08 2:01:23   68145M b4 axb4 Nd3 Ba7 Kf3 Bb8 Kg4 Bd6 h5 Kg7 Bc2 Kf6 
                              Ne1 Bf8 Bb3 Kg7 Ng2 Kf6 Nf4 Bh6 Nd5+ Ke5 Nxb4 Bd2 
                              Nd3+ Kf6 Bd1 Kg7 Kf5 Kh6 Nb4 Kg7 Nc2 Kh6 Ke4 Kg5 
                              Nb4 Kf6 Nd5+ Kg5 Kd3 Kf5 Nb4 Kg5 Bf3 Kf6 Nd5+ Kf5 
                              Kc2 Kg5 Nxc3 
Nodes: 68463550436
Nodes/second: 9347080
Best move: b4
Ponder move: axb4
I'm afraid there may be some output bug, somewhere? If I follow Stockfish's last line by hand it runs into this position:


[Event "ChessCafe Endgame Study"]
[Site "?"]
[Date "1997.08.08"]
[Round "?"]
[White "White to Play and Win"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/8/7k/p1N5/7P/2p5/1P2K3/3B2b1 w - -"]

1. b4 axb4 2. Nd3 Ba7 (2... Bh2 3. Ne1 Kh5 4. Ng2 Kg4
5. Kf2+ Kf5 6. Kf3 Kg6 7. Ke4 Bd6 8. Kd3 Be7 9. h5+ Kg5
10. Ne1 Bf8 11. Kc2 Kf5 12. Bf3 Kg5 13. Nd3 Bd6 14. Nf2)
3. Kf3 Bb8 4. Kg4 Bd6 5. h5 Kg7 6. Bc2 Kf6 7. Ne1 Bf8
8. Bb3 Kg7 9. Ng2 Kf6 10. Nf4 Bh6 11. Nd5+ Ke5 12. Nxb4 Bd2
13. Nd3+ Kf6 14. Bd1 Kg7 15. Kf5 Kh6 16. Nb4 Kg7 17. Nc2
Kh6 18. Ke4 Kg5 19. Nb4 Kf6 20. Nd5+ Kg5 21. Kd3 Kf5
22. Nb4 Kg5 23. Bf3 Kf6 24. Nd5+ Kf5 25. Kc2 Kg5 26. Nxc3 *

Which ends in a clearly drawn position. It is possible the PV is not accurately representing what produced the + 4 score or I made a mistake but it is very strange to see this high a score. The captures and checks seemed correct so far, I think I got the right line. Stockfish I'm sure evaluates the endposition as a draw also. This is Rainbow Serpent:

[d]8/8/8/6kP/8/2N2B2/2Kb4/8 b - -

Engine: Rainbow Serpent 1.6.3s(dc) (48 MB)
by Tord Romstad, Marco Costalba, Joona Kii

1.00 0:00 0.00 26...Bxc3 (67)

2.00 0:00 0.00 26...Bxc3 27.Kxc3 Kh6 (345)
.
.
.

52.01 0:33 0.00 26...Bxc3 27.Kxc3 Kh6 28.Kb2 Kg5
29.Kb1 Kh6 30.Kb2 (30.729.061) 931

53.01 0:35 0.00 26...Bxc3 27.Kxc3 Kh6 28.Kb2 Kg5
29.Kb1 Kh6 30.Kb2 (33.511.951) 935

54.01 0:39 0.00 26...Bxc3 27.Kxc3 Kh6 28.Kb2 Kg5
29.Kb1 Kh6 30.Kb2 (36.836.246) 935

55.01 0:43 0.00 26...Bxc3 27.Kxc3 Kh6 28.Kb2 Kg5
29.Kb1 Kh6 30.Kb2 (40.356.926) 938

56.01 0:46 0.00 26...Bxc3 27.Kxc3 Kh6 28.Kb2 Kg5
29.Kb1 Kh6 30.Kb2 (44.206.325) 941

best move: Bd2xc3 time: 0:49.828 min n/s: 942.845 nodes: 46.980.114

I think it is just the PV that is incorrect, but the score is from another position. I've seen this strange PVs occasionally in Rainbow Serpent too but it was some time ago. With multitreading maybe it is more vulnerable but I have no idea what it could be.

After for instance 15. Kh6 Rainbow Serpent would score that also high:

[d]8/8/7k/5K1P/8/2pN4/3b4/3B4 w - -

Engine: Rainbow Serpent 1.6.3s(dc) (48 MB)
by Tord Romstad, Marco Costalba, Joona Kii


30.01 1:28 +3.87 16.Nb4 Bg5 17.Ke4 Kg7 18.Nd5 Bd2
19.Kd3 Kh6 20.Kc2 Kg5 21.Be2 Kf5
22.Nb6 Be3 23.Nc4 Bd2 24.Kd3 Kg5
25.Nd6 Kh6 26.Ne4 Kg7 27.Kc2 Kh7
28.Bd1 Kh6 29.Bg4 (55.269.590) 626

31.01 2:03 +3.87 16.Nb4 Bg5 17.Ke4 Kg7 18.Nd5 Bd2
19.Kd3 Kh6 20.Kc2 Kg5 21.Be2 Kf5
22.Nb6 Be3 23.Nc4 Bd2 24.Kd3 Kg5
25.Nd6 Kh6 26.Ne4 Kg7 27.Kc2 Kh7
28.Bd1 Kh6 29.Bg4 (80.191.400) 648

32.01 3:09 +3.87 16.Nb4 Bg5 17.Ke4 Kg7 18.Nd5 Bd2
19.Kd3 Kh6 20.Kc2 Kg5 21.Be2 Kf5
22.Nb6 Be3 23.Nc4 Bd2 24.Kd3 Kg5
25.Nd6 Kh6 26.Ne4 Kg7 27.Kc2 Kh7
28.Bd1 Kh6 29.Bg4 (125.652.540) 662

33.01 19:41 +3.91 16.Nb4 Bg5 17.Ke4 Kg7 18.Nd5 Bd2
19.Kd3 Kh6 20.Kc2 Kg5 21.Be2 Kf5
22.Nb6 Be3 23.Nc4 Bd2 24.Kd3 Kg5
25.Nd6 Kh6 26.Ne4 Kg7 27.Kc2 Kh7
28.Bd1 Kh6 29.Bg4 (688.979.186) 583

best move: Nd3-b4 time: 21:02.562 min n/s: 576.613 nodes: 728.010.141

but it is still a draw, in spite of the high score.

In the initial position Rainbow Serpent goes to just under +2:

[d]8/8/7k/p1N5/7P/2p5/1P2K3/3B2b1 w - -

Engine: Rainbow Serpent 1.6.3s(dc) Build 182 (Athlon 2009 MHz, 64 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

1.00 0:00 +2.98 1.Na4 (65) 0

2.00 0:00 +2.98 1.Nd3 cxb2 2.Nxb2 (160) 0

3.00 0:00 +2.94 1.Nd3 cxb2 2.Nxb2 Bb6 3.Nc4 Bd8 (1.133) 5

4.00 0:00 +3.11 1.Nd3 cxb2 2.Nxb2 Bc5 3.Kd3 Bf2 4.h5 (2.650) 12

5.00 0:00 +3.11 1.Nd3 cxb2 2.Nxb2 Bb6 3.Kd3 Kg6 (4.651) 21

6.00 0:00 +2.94 1.Nd3 cxb2 2.Nxb2 Bb6 3.Kd3 Bd8 4.h5 Be7
5.Nc4 a4 (7.045) 32

7.00 0:00 +3.27++ 1.Nd3 cxb2 2.Nxb2 Bb6 3.Kd3 Bd8 4.h5 Be7
5.Nc4 a4 6.Kd4 (13.500) 57

8.00 0:00 +1.81-- 1.Nd3 cxb2 2.Nxb2 Bd4 3.Nc4 Bf6 (25.103) 100

9.00 0:00 +0.64 1.Nd3 cxb2 2.Nxb2 Bd4 3.Nc4 Bf6
4.Kd3 Bxh4 5.Bf3 Kg6 6.Bg4 Bf6 (65.359) 208

9.00 0:00 +1.21 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 (194.828) 415

10.00 0:00 +1.49 1.Ne4 cxb2 2.Nd2 Bb6 3.Kd3 Bd8 4.h5 Bg5
5.Nb1 Bf6 6.Bf3 Kg5 7.Kc2 Kf4 8.Bd5 (312.762) 500

11.00 0:00 +1.49 1.Ne4 cxb2 2.Nd2 Bh2 3.Kd3 Bf4 4.Nb1 Bg3
5.h5 Kg5 6.Kc2 Be5 7.Nd2 Kf4 8.Kb1 (572.415) 620

12.01 0:01 +1.77++ 1.Ne4 cxb2 2.Nd2 Bh2 3.Kd3 Bf4 4.Nb1 Bg3
5.h5 Kg5 6.Kc2 Be5 7.Nd2 Kf4 8.Kb1 (784.706) 678

13.01 0:01 +1.57 1.Ne4 cxb2 2.Nd2 Bd4 3.Kd3 Bf6 4.h5 Bg5
5.Nb1 Bf6 6.Kc2 Kg5 7.Nd2 Kf4 8.Kb1 Bd4
9.Nc4 (971.290) 714

14.01 0:02 +1.61 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Bf8
9.Bf3 Kf4 10.Bd5 Ke5 11.Bf7 Kd4
12.Bg6 (1.715.256) 801

15.01 0:02 +1.73 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Bf8
9.Bf3 Kf4 10.Bd5 Ke5 11.Bf7 Kd4
12.Nxa3 Bxa3 (2.427.696) 853

16.01 0:03 +1.73 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Bf8 11.Nc3 Kf4
12.Bd3 Ke3 13.Bg6 Kd2 14.Nb1+ (3.454.399) 898

17.01 0:05 +1.53-- 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Kh6 11.Nxa3 Bxa3 (4.902.524) 936

18.01 0:05 +1.53 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Kh6 11.Bd1 Kg5
12.Bf3 Bf8 13.Nc3 Kf4 14.Bd5 (5.655.685) 952

19.01 0:08 +1.53 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Kh6 11.Bd1 Kg5
12.Bf3 Bf8 13.Nc3 Kf4 14.Bd5 (8.974.258) 1014

20.01 0:11 +1.33-- 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Kh6 11.Bd1 Kg5
12.Bf3 Kh6 13.Be2 Kg5 14.Nxa3 (11.653.392) 1028

21.01 0:17 +0.80 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Kh6 11.Bd1 Kg5
12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 (18.160.491) 1063

22.01 0:29 +0.48 1.Ne4 cxb2 2.Nd2 a4 3.Kd3 Bf2 4.h5 Be1
5.Nb1 Bb4 6.Kc2 a3 7.Kb3 Kg5 8.Ka2 Kh6
9.Bf3 Kg5 10.Be2 Kh6 11.Bd1 Kg5
12.Bf3 Kh6 13.Be2 Kg5 14.Kb3 (31.302.678) 1049

22.02 0:50 +0.60 1.b4 axb4 2.Nd3 c2 3.Bxc2 Kh5 4.Ne5 Bb6
5.Nf3 Bd8 6.Bb3 Bxh4 7.Kd3 Kg4 8.Ke4 Bf6
9.Ne1 Kg5 10.Nd3 Kg4 11.Nc5 Kg5
12.Ne6+ Kg4 13.Bd1+ Kg3 14.Ba4 (52.064.857) 1028

23.01 1:03 +1.33++ 1.b4 axb4 2.Nd3 c2 3.Bxc2 Kh5 4.Ne1 Bb6
5.Ng2 Bd8 6.Bd1 Bxh4 7.Ke3+ Kg5
8.Kf3 b3 9.Bxb3 Kh5 10.Bf7+ Kg5
11.Be8 (64.793.088) 1025

24.01 1:47 +1.49 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Ne3+ Kg6 7.Kf3 Bg1
8.Bc2+ Kh5 9.Nf5 Kg6 10.Ke4 Bf2
11.Ke5 Bc5 12.Ng3+ Kh6 13.Bd1 Bb6
14.Kd5 (105.644.981) 984

25.01 2:33 +1.85 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Ne3+ Kg6 7.Kf3 Bg1
8.Nd5 Bh2 9.Kg4 Bd6 10.Bc2+ Kh6
11.h5 Bc5 12.Be4 Bf8 13.Bg6 Kg7
14.Kg5 (148.937.927) 968

26.01 3:32 +1.73 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf4
12.Nd3+ Ke4 13.Nf2+ Kf5 14.Be2 (202.200.754) 950

27.01 5:10 +1.73 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Kb3 Kg5 13.Nd3 Bd6 14.Bf3 (296.154.378) 953

28.01 7:55 +1.89 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Kb3 Kg5 13.Nd3 Bd6 14.Bf3 (456.466.670) 959

29.01 11:59 +1.89 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Kb3 Kg5 13.Nd3 Bd6 14.Bf3 (689.426.546) 958

30.01 19:16 +1.81 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Bf3 Kg5 13.Nd3 Bd6 14.Nf2 (1.142.811.006) 987

31.01 24:44 +1.89 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Bf3 Kg5 13.Nd3 Bd6 14.Nf2 (1.450.388.063) 977

32.01 37:12 +1.89 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Bf3 Kg5 13.Nd3 Bd6 14.Nf2 (2.108.905.732) 944

33.01 47:03 +1.89 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Bf3 Kg5 13.Nd3 Bd6 14.Nf2 (2.499.605.370) 885

34.01 72:00 +1.97 1.b4 axb4 2.Nd3 Bh2 3.Ne1 Kh5 4.Ng2 Kg4
5.Kf2+ Kf5 6.Kf3 Kg6 7.Ke4 Bd6 8.Kd3 Be7
9.h5+ Kg5 10.Ne1 Bf8 11.Kc2 Kf5
12.Bf3 Kg5 13.Nd3 Bd6 14.Nf2
{[d]8/8/3b4/6kP/1p6/2p2B2/2K2N2/8 b - - 0 1
White can't make progress =} (4.140.168.756) 958

Eelco
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
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