Endgame study, Costeff 1996

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Rebel, chrisw

zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Endgame study, Costeff 1996

Post by zullil »

afzzq wrote:
zullil wrote: I'm still missing something. What should be different in what follows?

5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1

Code: Select all

[Event "?"]
[Site "?"]
[Date "2010.05.14"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1"]

1. Rb1 a5 2. Rd1 a6 3. Kf7 d5 4. e6 d4 5. e7 d3 6. e8=Q d2 7. Rxd2 Nf3 8. Rd3
g1=Q *
I see your point now. That is a difficult line. Say 9 R:f3 Qa7+ and it looks dangerous. Perhaps someone with large tablebases can shed more light.
Well, here's Stockfish-1.7.1's take, at depth 41, starting with Rf3 Qa7+. It gives a +89 score for White:

Code: Select all

info depth 41 score cp 8914 time 9571042 nodes 97197989258 nps 10155423 pv d3f3 g1a7 f7e6 a7b6 e6f5 b6b1 f5g5 b1c1 g5h5 c1d1 e8e4 h1g2 e4g4 g2h1 h5h4 d1d8 h4g3 d8d4 g4h5 d4g7 g3h3 g7d7 f3f5 d7d3 h5f3 d3f3 f5f3 h1g1 f3g3 g1f2 h3h2 f2e2 g3g5 e2d3 g5a5 d3c4 h2g1 c4d4 g1f2 d4c4 a5a6 c4b3 f2e3 b3c4 a6b6 c4d5 a4a5 d5c5 e3e2 c5d4 a5a6 d4c5 a6a7 c5b6 a7a8q b6c5 e2e3 c5d6 e3e4 
afzzq

Re: Endgame study, Costeff 1996

Post by afzzq »

zullil wrote: I'm still missing something. What should be different in what follows?

5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1

Code: Select all

[Event "?"]
[Site "?"]
[Date "2010.05.14"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1"]

1. Rb1 a5 2. Rd1 a6 3. Kf7 d5 4. e6 d4 5. e7 d3 6. e8=Q d2 7. Rxd2 Nf3 8. Rd3
g1=Q *

What about 9 R:f3 Qg3! If 10 Qc6 then Q:f3 is a draw.
afzzq

Re: Endgame study, Costeff 1996

Post by afzzq »

afzzq wrote:
zullil wrote: I'm still missing something. What should be different in what follows?

5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1

Code: Select all

[Event "?"]
[Site "?"]
[Date "2010.05.14"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1"]

1. Rb1 a5 2. Rd1 a6 3. Kf7 d5 4. e6 d4 5. e7 d3 6. e8=Q d2 7. Rxd2 Nf3 8. Rd3
g1=Q *

What about 9 R:f3 Qg3! If 10 Qc6 then Q:f3 is a draw.
Ignore my last two attempts to refute the line (...Qa7+? and ...Qg3+?).

The right refutation is 9 R:f3 Qd1! What does Stockfish say to that?
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Endgame study, Costeff 1996

Post by zullil »

afzzq wrote:
afzzq wrote:
zullil wrote: I'm still missing something. What should be different in what follows?

5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1

Code: Select all

[Event "?"]
[Site "?"]
[Date "2010.05.14"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1"]

1. Rb1 a5 2. Rd1 a6 3. Kf7 d5 4. e6 d4 5. e7 d3 6. e8=Q d2 7. Rxd2 Nf3 8. Rd3
g1=Q *

The right refutation is 9 R:f3 Qd1! What does Stockfish say to that?

Code: Select all

info depth 35 score cp 8924 time 145740 nodes 1296827975 nps 8898229 pv f3f5 d1b3 f7f6 b3c3 e8e5 c3e5 f6e5 h1g2 f5g5 g2f2 g5h5 f2g2 e5d6 h2h1q h5h1 g2h1 d6c6 h1g2 c6b6 g2g3 b6a5 g3f4 a5a6 f4g3 a6b5 g3f2 a4a5 f2g2 b5b6 g2g1 a5a6 g1g2 a6a7 g2f2 a7a8q f2e3 b6c5 e3f4 c5d4 f4f5 a8e4 f5f6 d4d5 f6g5 d5e6 g5h5 e6f7 
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Endgame study, Costeff 1996

Post by zullil »

afzzq wrote:
afzzq wrote:
zullil wrote: I'm still missing something. What should be different in what follows?

5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1

Code: Select all

[Event "?"]
[Site "?"]
[Date "2010.05.14"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "5K2/p2p4/p7/4P3/P7/8/1R4pp/6nk w - - 0 1"]

1. Rb1 a5 2. Rd1 a6 3. Kf7 d5 4. e6 d4 5. e7 d3 6. e8=Q d2 7. Rxd2 Nf3 8. Rd3
g1=Q *

The right refutation is 9 R:f3 Qd1! What does Stockfish say to that?

Code: Select all

info depth 37 score cp 13082 lowerbound time 401614 nodes 3464649433 nps 8626814 pv f3f5 d1b3 f7f6 b3c3 e8e5 c3e5 f6e5 h1g2 f5g5 g2f2 g5h5 f2g2 e5d6 h2h1q h5h1 g2h1 d6c6 h1g2 c6b6 g2f2 b6a6 f2e3 a6a5 e3d4 a5b5 d4d5 a4a5 d5d6 b5b6 d6e7 a5a6 e7f7 a6a7 f7g6 b6b5 g6f7 a7a8q f7f6 b5c4 f6f7 c4c5 f7e6 c5d4 e6d7 a8b7 d7e6 b7c6 e6e7 d4e5 e7d8 c6b7 
yanquis1972
Posts: 1766
Joined: Wed Jun 03, 2009 12:14 am

Re: Endgame study, Costeff 1996

Post by yanquis1972 »

the most certain SF eval yet comes next ply --

[+144.08] d=38 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qxe5+ 14.Kxe5 Kg2 15.Rg5+ Kf2 16.Rh5 Kg3 17.Kd4 Kg2 18.Kc5 h1Q 19.Rxh1 Kxh1 20.Kb6 Kg2 21.Kxa5 Kf2 22.Kxa6 Kg3 23.a5 Kf2 24.Kb6 Kg3 25.a6 Kf2 26.a7 Ke3 27.a8Q Kf4 28.Kc6 Ke3 29.Kb5 Kf2 (1:01:01) 55289555kN
[+89.34] d=37 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qxe5+ 14.Kxe5 Kg2 15.Rg5+ Kf2 16.Rh5 Kg3 17.Kd4 Kg2 18.Kc5 h1Q 19.Rxh1 Kxh1 20.Kb6 Kg2 21.Kxa5 Kf2 22.Kxa6 Kg3 23.a5 Kf2 24.Kb6 Kg3 25.a6 Kf2 26.a7 Ke3 27.a8Q Kf2 28.Kc5 Ke3 29.Qd5 Ke2 30.Kd4 Kf2 31.Qh5 Kg2 32.Ke4 Kg3 33.Ke3 Kg2 (0:39:45) 35529282kN
[+89.24] d=36 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Kf5 32.Qc8+ Ke4 33.Qe8+ Kf3 34.Kd4 Kf4 35.Qe4+ Kg5 36.Ke5 (0:20:15) 17503109kN
[+89.19] d=35 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Kf5 32.Qc8+ Ke4 33.Qe8+ Kf3 34.Kd4 Kf4 35.Qe4+ Kg3 (0:13:21) 11942891kN
[+89.14] d=34 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Kf5 32.Qc8+ Ke4 33.Qc7 Ke3 34.Qh2 (0:05:53) 5206991kN
[+89.14] d=33 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Ke3 32.Kd5 Kf4 33.Qa1 (0:01:51) 1577726kN
[+89.14] d=32 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Ke3 32.Kd5 Kf4 (0:00:57) 799936kN
[+89.14] d=31 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Ke3 32.Kd5 (0:00:26) 344854kN
[+89.14] d=30 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc5 Ke3 (0:00:14) 180116kN
[+89.04] d=29 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kc6 Kg3 32.Kd5 Kf4 33.Kd4 (0:00:08) 104840kN
[+88.94] d=28 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:05) 61579kN
[+88.94] d=27 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:03) 36560kN
[+77.09] d=26 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:02) 21465kN
[+77.08] d=25 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:01) 12415kN
[+77.08] d=24 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:01) 9431kN
[+77.08] d=23 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:01) 5545kN
[+77.09] d=23 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Qe7 Qxe7+ 17.Kxe7 Kg1 18.Rg5+ Kf1 19.Rh5 Kg2 20.Kd6 h1Q 21.Rxh1 Kxh1 22.Kc5 Kg2 23.Kb6 Kg3 24.Kxa6 Kf4 25.Kxa5 Kf5 26.Kb6 Kf4 27.a5 Kf5 28.a6 Kf4 29.a7 Kf5 30.a8Q Kf4 31.Kb7 Ke4 32.Kb6+ Ke3 33.Kb5 Kf4 34.Kb6 Ke3 (0:00:00) 4474kN
[+10.10] d=22 10.Rf5 Qb3+ 11.Qe6 Qb7+ 12.Kf6 Qb2+ 13.Qe5 Qb6+ 14.Kg7 Qg1+ 15.Kf7 Qa7+ 16.Kf8 Qa8+ 17.Ke7 Qa7+ 18.Ke6 Qb6+ 19.Kd7 Qa7+ 20.Kc6 Qa8+ 21.Kc5 Qc8+ 22.Kd4 Qc1 23.Qd5+ Kg1 24.Rg5+ Qxg5 25.Qxg5+ Kh1 26.Qd5+ Kg1 27.Qe4 Kf2 28.Qh4+ Kg1 29.Ke3 h1N 30.Qg5+ Kf1 31.Qxa5 (0:00:00) 2642kN
[+77.08] d=21 10.Rf5 Qb3+ 11.Qe6 Qxe6+ 12.Kxe6 Kg2 13.Rg5+ Kh1 14.Rh5 Kg1 15.Kd6 h1B 16.Rxh1+ Kxh1 17.Kc5 Kg2 18.Kb6 Kg3 19.Kxa6 Kf4 20.Kxa5 Kf5 21.Kb6 Kf4 22.a5 Kf5 23.a6 Kf4 24.Kc5 Kg3 25.Kb6 Kh4 26.a7 Kg5 27.a8Q Kf4 28.Kb7 Ke4 29.Kb6+ Ke3 30.Kb5 Kf4 31.Kb6 Ke3 (0:00:00) 646kN
[+77.08] d=20 10.Rf5 Qb3+ 11.Qe6 Qxe6+ 12.Kxe6 Kg2 13.Rg5+ Kf3 14.Rh5 Kg2 15.Kd6 h1Q 16.Rxh1 Kxh1 17.Kc5 Kg2 18.Kb6 Kf2 19.Kxa5 Ke3 20.Kxa6 Kf2 21.a5 Kg3 22.Kb7 Kg2 23.Kb6 Kf2 24.a6 Kg2 25.Kc5 Kf2 26.a7 Ke2 27.a8Q Ke3 28.Kb5 Kf4 29.Kb6 Ke3 30.Kb5 (0:00:00) 436kN
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Endgame study, Costeff 1996

Post by zullil »

zullil wrote:[D]4Q3/5K2/p7/p7/P7/3R1n2/7p/6qk w - - 0 8

What will happen here?
Stockfish-1.7.1 gives

Code: Select all

42  >+131.64 6:19:29  232116M Rxf3 Qa7+ Ke6 Qb6+ Kf5 Qb1+ Kg5 Qc1+ Kh5 Qd1 Qe4 
                              Kg2 Qg4+ Kh1 Kh4 Qd8+ Kg3 Qd4 Qh5 Qg7+ Kh3 Qd7+ 
                              Rf5 Qd3+ Qf3+ Qxf3+ Rxf3 Kg1 Rg3+ Kf2 Kxh2 Ke2 
                              Rb3 Kd2 Kg2 Kc2 Re3 Kb2 Kg3 Kc2 Kf4 
42  >+132.12 8:38:40  322978M Rxf3 
yanquis1972
Posts: 1766
Joined: Wed Jun 03, 2009 12:14 am

Re: Endgame study, Costeff 1996

Post by yanquis1972 »

now an evaluation drop -- !!

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "4Q3/5K2/p7/p7/P7/5R2/7p/3q3k w - - 0 10"]
[SetUp "1"]

10. Rf5 Qb3+ 11. Qe6 Qb7+ 12. Kf6 Qb2+ 13. Qe5 Qxe5+ 14. Kxe5 Kg2 15. Rg5+ Kf2
16. Rh5 Kg3 17. Kd4 Kg2 18. Kc5 h1=Q 19. Rxh1 Kxh1 20. Kb6 Kg2 21. Kxa5 Kf2 22.
Kxa6 Kg3 23. a5 Kf2 24. Kb6 Kg3 25. a6 Kf2 26. a7 Ke3 27. a8=Q Kf4 28. Kc6 Ke3
29. Qf8 Kd3 30. Qf3+ Kc2 31. Qe2+ Kb1 32. Qd2 Ka1 33. Kb5 Kb1 34. Kb4 Ka1 35.
Kc3 {(2:28:56) 143222160kN}{[%eval 89.50,38,stockfish 1.7.1]} *
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Endgame study, Costeff 1996

Post by zullil »

yanquis1972 wrote:now an evaluation drop -- !!

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "4Q3/5K2/p7/p7/P7/5R2/7p/3q3k w - - 0 10"]
[SetUp "1"]

10. Rf5 Qb3+ 11. Qe6 Qb7+ 12. Kf6 Qb2+ 13. Qe5 Qxe5+ 14. Kxe5 Kg2 15. Rg5+ Kf2
16. Rh5 Kg3 17. Kd4 Kg2 18. Kc5 h1=Q 19. Rxh1 Kxh1 20. Kb6 Kg2 21. Kxa5 Kf2 22.
Kxa6 Kg3 23. a5 Kf2 24. Kb6 Kg3 25. a6 Kf2 26. a7 Ke3 27. a8=Q Kf4 28. Kc6 Ke3
29. Qf8 Kd3 30. Qf3+ Kc2 31. Qe2+ Kb1 32. Qd2 Ka1 33. Kb5 Kb1 34. Kb4 Ka1 35.
Kc3 {(2:28:56) 143222160kN}{[%eval 89.50,38,stockfish 1.7.1]} *
But the line you give is a clear win for White!
yanquis1972
Posts: 1766
Joined: Wed Jun 03, 2009 12:14 am

Re: Endgame study, Costeff 1996

Post by yanquis1972 »

you're right, i realized that after checking it as well. i assume the eval drop was simply a result of stockfish yo-yo-ing & not an actual reconsideration.