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Subject: Re: New Tough Endgame Test Suite

Author: Dann Corbit

Date: 10:31:53 06/02/00

Go up one level in this thread


On June 02, 2000 at 04:37:15, Paulo Soares wrote:
>On June 01, 2000 at 17:01:13, José de Jesús García Ruvalcaba wrote:
>>On June 01, 2000 at 13:01:25, Vincent Lejeune wrote:
>>>On June 01, 2000 at 11:48:37, José de Jesús García Ruvalcaba wrote:
>>>>On June 01, 2000 at 05:30:31, Vincent Lejeune wrote:
>>>>>On May 31, 2000 at 13:41:45, Dann Corbit wrote:
>>>>>>CAP records (some of them do not appear to have faired well):
>>>>>>6k1/8/2P5/p6p/5bP1/7P/2B2K2/8 w - - acd 20; acn 1174673323; acs 3601; ce
>>>>>>153; pv gxh5 Kg7 Kf3 Bh2 Kg4 Kh6 Bd1 Bc7 Kf5 Bb6 Ke6 Bc7 Kd7 Bf4 Kd8 Be5;
>>>>>
>>>>>I really doubt that gxh5 is the best move because the h's pawn have the wrong
>>>>>square colour to promote, if the black bishop stay on the h2-b8 diagonal with
>>>>>can make no progress.
>>>>>1.g5 seems to be stronger
>>>>
>>>>	g5 loses a pawn outright. I agree that gxh5 is a poor move. I think Kf3 is
>>>>better.
>>>>José.
>>>
>>>If 1..Bxg5?, 2.c7! wins a queen ...
>>
>>	You are right! This happens to me frequently when I do not set up real board
>>and pieces to analyze.
>>	After 1. g5 black must play h4 (otherwise white plays h4, then Bd1 tying
>>black's king to defent the h5 pawn, and then the white king supports the c-pawn
>>and wins). 1. Kf3 attacks the bishop, so white can play g5 the next move.
>>	Interesting position, and one in which a little knowledge for opposite-coloured
>>bishop endings is extremely helpful (in this case: when trying to win make both
>>bishops "good", and when trying to draw make both bishops "bad").
>>José.
>
>Strange, I made a long analyse from this position and it seemed
>that 1. g5 and 1. Kg3 are winner moves.
>

On a deep search, all three of gxh5, g5, and Kf3 fare about the same.  Here are
the positions *after* each of those choices are made, analyzed for three hours:


[D] 6k1/8/2P5/p6p/5bP1/5K1P/2B5/8 b - - acd 20; acn 2045418075; acs 10002; ce
-171; pv Bc7 gxh5 Kg7 Kg4 Kh6 Ba4 Be5 Bd1 Bh2 Kf5 Bc7 Ke6 Bh2 Kd7 Bf4 Kd8 Bg3
Kd7 Kg5;

[D] 6k1/8/2P5/p6P/5b2/7P/2B2K2/8 b - - acd 21; acn 2022412756; acs 10001; ce
-161; pv Kg7 Kf3 Bc7 Kg4 Kh6 Bd1 Bd8 Kf5 Bc7 Ke6 Bh2 Kd5 Bc7 Kd4 Bb6+ Kc4 Bc7
Bg4 Be5 Kd5 Bg3 Ke6;

[D] 6k1/8/2P5/p5Pp/5b2/7P/2B2K2/8 b - - acd 21; acn 2095662806; acs 10001; ce
-182; pv h4 Kf3 Be5 Kg4 Bg3 Ba4 Kf7 Kh5 Kg7 Bc2 Kg8 Kh6 Bf4 Bb3+ Kh8 Kh5 Bc7
Kxh4 Bd8 Kg4 Bc7;

Naturally, since we are one ply forward, we are looking for the most negative
score.  1/5 of a pawn separates the best from the worst of the three choices.

However, the first and the third positions both had fail lows at the end of
their searchs, so these are probably the best choices.

pondering disabled.
EGTB cache memory = 6M bytes.
hash table memory = 24M bytes.
pawn hash table memory = 8M bytes.
EGTB access enabled
using tbpath=e:/crafty/release/tb,F:/KBP
6 piece tablebase files found
1943kb of RAM used for TB indices and decompression tables


Crafty v17.10

White(1): st 10000
search time set to 10000.00.
White(1): epdpfga epd.epd epd.out
PFGA: EPD record: 1
end-game phase
              clearing hash tables
              time surplus   0.00  time limit 166:40 (166:40)
         nss  depth   time  score   variation (1)
               11     0.78  -1.46   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Bh2 5. h4 Bc7 6. Bd1 Bh2
               11->   0.98  -1.46   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Bh2 5. h4 Bc7 6. Bd1 Bh2
               12     1.04     --   1. ... Bc7
               12     1.93  -1.56   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    h4 Bd8 5. Bb3 Bc7 6. Bd1 <HT>
               12->   2.39  -1.56   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    h4 Bd8 5. Bb3 Bc7 6. Bd1 <HT>
               13     7.38  -1.44   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf4 Bc7+ 6. Ke4 Bb6 7. Bg4
                                    Bc7 8. h4
               13->   8.68  -1.44   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf4 Bc7+ 6. Ke4 Bb6 7. Bg4
                                    Bc7 8. h4
               14     9.36     --   1. ... Bc7
               14    16.28  -1.84   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Bd8 4.
                                    Bd1 Bc7 5. Kg5 Bd8+ 6. Kf4 Bc7+ 7.
                                    Kf5 Bd8 8. Ke6 Kh6 9. Kd6
               14    41.86  -1.81   1. ... Be5 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Bd1 Bc7 5. Kf5 a4 6. Bxa4 Kxh5 7. Ke6
                                    Kh4 8. Kd7
               14->  42.56  -1.81   1. ... Be5 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Bd1 Bc7 5. Kf5 a4 6. Bxa4 Kxh5 7. Ke6
                                    Kh4 8. Kd7
               15     1:08  -1.84   1. ... Be5 2. gxh5 Kg7 3. Ke4 Bh2 4.
                                    Kd5 Kh6 5. Bd1 a4 6. Bxa4 Kxh5 7. Bd1+
                                    Kh4 8. Bg4 Bc7 9. Bf5
               15     1:48  -1.80   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 a4 6. Bxa4 Kxh5 7. Bd1+
                                    Kh4 <HT>
               15->   1:53  -1.80   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 a4 6. Bxa4 Kxh5 7. Bd1+
                                    Kh4 <HT>
               16     2:50  -1.80   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Kf5 a4 7. Bxa4
                                    Kxh5 <HT>
               16->   3:51  -1.80   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Kf5 a4 7. Bxa4
                                    Kxh5 <HT>
               17     6:27  -1.78   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 <HT>
               17->   8:08  -1.78   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Ba4 <HT>
               18    16:38  -1.73   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Kf5 Bc7 7. Ke6
                                    Bh2 8. Kd5 Kg7 9. Bc2 Kh6 10. Bg6
               18->  21:44  -1.73   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Kf5 Bc7 7. Ke6
                                    Bh2 8. Kd5 Kg7 9. Bc2 Kh6 10. Bg6
               19    58:38  -1.71   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Kf5 Bc7 7. Ke6
                                    Bh2 8. Kd7 Bf4 9. Kd8 Bg3 10. Kd7 Kg5
               19->  85:08  -1.71   1. ... Bc7 2. gxh5 Kg7 3. Kg4 Kh6 4.
                                    Ba4 Be5 5. Bd1 Bh2 6. Kf5 Bc7 7. Ke6
                                    Bh2 8. Kd7 Bf4 9. Kd8 Bg3 10. Kd7 Kg5
               20   110:51     --   1. ... Bc7
              time=166:40  cpu=100%  mat=-1  n=2045418075  fh=9%  nps=204535
              ext-> checks=249624906 recaps=1915421 pawns=14036655 1rep=24278480
thrt:90215
              predicted=0  nodes=2045418075  evals=231086920
              endgame tablebase-> probes done=2403985  successful=32940
PFGA: EPD record: 2
              time surplus   0.00  time limit 166:40 (166:40)
         nss  depth   time  score   variation (1)
               11     0.50  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 Bc7 6. Ke6 <HT>
               11->   0.80  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 Bc7 6. Ke6 <HT>
               12     0.95  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 Bc7 6. Ke6 <HT>
               12->   1.42  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 Bc7 6. Ke6 <HT>
               13     1.78  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 Bc7 6. Ke6 <HT>
               13->   2.55  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bh2 5. Kf5 Bc7 6. Ke6 <HT>
               14     5.14  -1.60   1. ... Kg7 2. Kf3 Bc7 <HT>
               14->   6.40  -1.60   1. ... Kg7 2. Kf3 Bc7 <HT>
               15    10.35  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bb3 Kg7 5. Kg5 Bd8+ 6. Kf5 Kh6 7. Bd1
                                    Bc7 8. Ke6 <HT>
               15->  12.62  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bb3 Kg7 5. Kg5 Bd8+ 6. Kf5 Kh6 7. Bd1
                                    Bc7 8. Ke6 <HT>
               16    26.71  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bb3 Kg7 5. Kg5 Bd8+ 6. Kf5 Kh6 7. Bd1
                                    Bc7 8. Ke6 <HT>
               16->  32.58  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bb3 Kg7 5. Kg5 Bd8+ 6. Kf5 Kh6 7. Bd1
                                    Bc7 8. Ke6 <HT>
               17     1:08  -1.88   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf5 a4 6. Bxa4 Kxh5 7. Bd1+
                                    Kh4 8. Bg4 Bc7 9. Ke6 Kg5 10. Kd7
               17->   8:20  -1.88   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf5 a4 6. Bxa4 Kxh5 7. Bd1+
                                    Kh4 8. Bg4 Bc7 9. Ke6 Kg5 10. Kd7
               18    10:07  -1.79   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Ba4 Bc7 6. Bc2 Bd8 7. Bd1
                                    Bb6 8. Bb3 <HT>
               18->  11:21  -1.79   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Ba4 Bc7 6. Bc2 Bd8 7. Bd1
                                    Bb6 8. Bb3 <HT>
               19    17:06  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Ba4 Bc7 6. Bc2 Bd8 7. Bd1
                                    Bb6 8. Kf5 Bc7 9. Kf6 Bg3 <HT>
               19->  19:43  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Ba4 Bc7 6. Bc2 Bd8 7. Bd1
                                    Bb6 8. Kf5 Bc7 9. Kf6 Bg3 <HT>
               20    36:04  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf5 Bc7 6. Kf6 Bg3 7. Ke6
                                    Bc7 8. Kf5 Bd6 9. Kg4 Kh7 10. Kg5 Kg7
                                    11. Ba4
               20->  50:07  -1.60   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf5 Bc7 6. Kf6 Bg3 7. Ke6
                                    Bc7 8. Kf5 Bd6 9. Kg4 Kh7 10. Kg5 Kg7
                                    11. Ba4
               21   122:59  -1.61   1. ... Kg7 2. Kf3 Bc7 3. Kg4 Kh6 4.
                                    Bd1 Bd8 5. Kf5 Bc7 6. Ke6 Bh2 7. Kd5
                                    Bc7 8. Kd4 Bb6+ 9. Kc4 Bc7 10. Bg4
                                    Be5 11. Kd5 Bg3 12. Ke6
              time=166:40  cpu=100%  mat=-2  n=2022412756  fh=3%  nps=202231
              ext-> checks=97023963 recaps=1009590 pawns=22546688 1rep=2784174
thrt:112256
              predicted=0  nodes=2022412756  evals=431137305
              endgame tablebase-> probes done=8149776  successful=131257
PFGA: EPD record: 3
              time surplus   0.00  time limit 166:40 (166:40)
         nss  depth   time  score   variation (1)
               10     0.62  -1.09   1. ... Kg7 2. g6 Bc7 3. Kf3 Bh2 4.
                                    Ke3 Bc7 5. Kd4 Bb6+ 6. Kd5 Bc7
               10->   0.88  -1.09   1. ... Kg7 2. g6 Bc7 3. Kf3 Bh2 4.
                                    Ke3 Bc7 5. Kd4 Bb6+ 6. Kd5 Bc7
               11     1.59  -1.09   1. ... Kg7 2. g6 Bc7 3. Kf3 Bh2 4.
                                    Ke3 Be5 5. Ke4 Bh2 6. Kd5 Bc7
               11->   2.75  -1.09   1. ... Kg7 2. g6 Bc7 3. Kf3 Bh2 4.
                                    Ke3 Be5 5. Ke4 Bh2 6. Kd5 Bc7
               12     4.97  -1.11   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. Ke3 Bg3 6. Bf5 Bc7 7. g6
               12->   7.68  -1.11   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. Ke3 Bg3 6. Bf5 Bc7 7. g6
               13    11.51  -1.14   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. g6 Kf6 6. Ke3 a4 7. g7 Kxg7
                                    8. Bxa4
               13->  15.90  -1.14   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. g6 Kf6 6. Ke3 a4 7. g7 Kxg7
                                    8. Bxa4
               14    20.95  -1.14   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. g6 Kf6 6. Ke3 a4 7. Bxa4
                                    Kxg6 8. Bb3
               14->  30.60  -1.14   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. g6 Kf6 6. Ke3 a4 7. Bxa4
                                    Kxg6 8. Bb3
               15    46.04  -1.15   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. g6 a4 6. Bxa4 Kxg6 7. Bc2+
                                    Kg5 8. Ke4 Kf6 9. Kd5
               15->   1:07  -1.15   1. ... Kg7 2. Kf3 Bh2 3. Ke3 Bc7 4.
                                    Kd4 h4 5. g6 a4 6. Bxa4 Kxg6 7. Bc2+
                                    Kg5 8. Ke4 Kf6 9. Kd5
               16     1:32     --   1. ... Kg7
               16    47:00  -2.02   1. ... Kg7 2. Kf3 Bc7 3. h4 Bb8 4.
                                    Ke4 Kg6 5. Kd5+ Kf7 6. Bd1 Kf8 7. Bxh5
                                    a4 8. g6 Bg3 9. Bd1 a3
               16    50:24     ++   1. ... h4!!
               16    50:54  -1.53   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Ke6 a4 7. Bxa4
                                    Kxg6 8. Bc2+ Kg5 9. Kd7 Be5 10. Be4
               16->  51:04  -1.53   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Ke6 a4 7. Bxa4
                                    Kxg6 8. Bc2+ Kg5 9. Kd7 Be5 10. Be4
               17    51:41  -1.60   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Ke6 a4 7. Kd7
                                    a3 8. Bb1 a2 9. Bxa2 Kxg6 10. Bb1+
                                    Kg5 11. Be4
               17->  52:52  -1.60   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Ke6 a4 7. Kd7
                                    a3 8. Bb1 a2 9. Bxa2 Kxg6 10. Bb1+
                                    Kg5 11. Be4
               18    54:44  -1.60   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Kg5 Bd6 7. Kxh4
                                    a4 8. Bxa4 Kxg6 9. Bc2+ Kf6 10. Kg4
                                    Bc7 11. Bf5
               18->  58:41  -1.60   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Kg5 Bd6 7. Kxh4
                                    a4 8. Bxa4 Kxg6 9. Bc2+ Kf6 10. Kg4
                                    Bc7 11. Bf5
               19    65:12  -1.58   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Kg5 Bc7 7. Kxh4
                                    a4 8. Bxa4 Kxg6 9. Kg4 Kf6 10. h4 Ke5
                                    11. h5
               19->  74:46  -1.58   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Kf5 Kf7 5. g6+ Kg7 6. Kg5 Bc7 7. Kxh4
                                    a4 8. Bxa4 Kxg6 9. Kg4 Kf6 10. h4 Ke5
                                    11. h5
               20    88:26  -1.82   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Ba4 Kf7 5. Kh5 Kg7 6. Bc2 Kg8 7. Kh6
                                    Bf4 8. Bb3+ Kh8 9. Kh5 Bc7 10. Kxh4
                                    Bd8 11. Kg4 Bc7
               20-> 125:22  -1.82   1. ... h4 2. Kf3 Be5 3. Kg4 Bg3 4.
                                    Ba4 Kf7 5. Kh5 Kg7 6. Bc2 Kg8 7. Kh6
                                    Bf4 8. Bb3+ Kh8 9. Kh5 Bc7 10. Kxh4
                                    Bd8 11. Kg4 Bc7
               21   126:43     --   1. ... h4
              time=166:40  cpu=99%  mat=-1  n=2095662806  fh=14%  nps=209554
              ext-> checks=227510789 recaps=628105 pawns=16403120 1rep=11235336
thrt:96399
              predicted=0  nodes=2095662806  evals=169751199
              endgame tablebase-> probes done=1356541  successful=9507
Black(1): quit
execution complete.




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