UCT surprise for checkers !

[hgm]

Have you really tried that? It is not so obvious to me. It seems that at least any material advantage would be well preserved, and even grow expoetially.

[Michel]

Have you really tried that? It is not so obvious to me. It seems that at least any material advantage would be well preserved, and even grow expoetially.

It is true I have not tried it. This should be easy to test with a random mover.

[Daniel Shawul]

Quality of montecarlo playouts in standard chess is very hard to improve it seems. It is full of tactics that I couldn't improve even after using SEE and other tactical staff related to checking. Suicide chess variants however sound like good candidates for UCT. They are more like checkers in the following ways

- forced nature of captures
- king is like any other piece

This signicantly improved the use of UCT in "chess" I am getting good results but the alpha-beta engine is too strong currently. It hasn't even lost a game.

[Daniel Shawul]

First win for the UCT version. It seems I was using a small exploration factor of 0.44. When I changed that to 0.6 it won its first game

Code: Select all

[Event "Computer Chess Game"]
[Site "CEE-3624-AB52"]
[Date "2011.04.02"]
[Round "-"]
[White "NebiyuChess_1.2"]
[Black "NebiyuChess_1.2"]
[Result "0-1"]
[TimeControl "40/120"]
[Variant "suicide"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1"]
[SetUp "1"]

{--------------
r n b q k b n r
p p p p p p p p
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
P P P P P P P P
R N B Q K B N R
white to play
--------------}
1. g3 {+0.00/23} g6 2. Nh3 {+1.35/24 2.3} g5 3. Nxg5 a6 4. Nxf7
{+7.40/25 2.2} Kxf7 5. Na3 {+10.70/25 2.9} b6 6. Nb5 {+23.45/24 2.9} axb5
7. c4 {+23.60/25 3} Rxa2 8. Rxa2 {+21.20/26 2.4} bxc4 9. Qb3
{+21.15/24 2.4} cxb3 10. Ra5 {+21.80/23 3} bxa5 11. Kd1 {+9.40/27 3} e6 12.
Kc2 {+0.05/28 8} bxc2 13. h4 {+0.60/27 3} Qxh4 14. gxh4 {+1.30/25 2.8} Ba3
15. bxa3 Kg6 16. e3 {-1.40/27 6} Kg5 17. hxg5 Nf6 18. Rxh7 {+1.40/27 2.5}
Rxh7 19. gxf6 Re7 20. fxe7 d6 21. e8=Q {-299.86/29 2.9} Bb7 22. Qxb8
{-299.88/35 2.7} Bc8
{White resigns} 0-1

Just in case there is doubt if the UCT version actually knows it is winning
, here is the log file which shows a score of 100% towards the end of the game.

ht 1048576 X 64 = 64MB
<COMMAND LINE>
==============================
<000000000484>xboard
<000000000484>protover 2
feature done=0
feature name=1 myname="NebiyuChess_1.2"
feature sigint=0 sigterm=0
feature variants="8x8+0_normal,8x8+0_spartan,8x8+0_knightmate,8x8+0_shatranj,8x8+0_makruk,8x8+0_berolina,10x10+0_jetan,10x10+0_grand,10x8+0_gothic,10x8+0_capablanca,12x8+0_courier,8x8+0_suicide,8x8+0_giveaway,8x8+0_alien,10x10+0_alien"
feature san=0 usermove=1 setboard=1 draw=0 colors=0
feature smp=0 memory=0 egt="nebiyu"
feature option="variant -combo 8x8+0_normal /// 8x8+0_spartan /// 8x8+0_knightmate /// 8x8+0_shatranj /// 8x8+0_makruk /// 8x8+0_berolina /// 10x10+0_jetan /// 10x10+0_grand /// 10x8+0_gothic /// 10x8+0_capablanca /// 12x8+0_courier /// 8x8+0_suicide /// 8x8+0_giveaway /// 8x8+0_alien /// 10x10+0_alien"
feature option="log -check 0"
feature option="clear_hash -button"
feature option="resign -spin 800 100 30000"
feature option="use_iid -check 1"
feature option="use_singular -check 0"
feature option="use_lmr -check 1"
feature option="use_futility -check 1"
feature option="use_qsearch_evasion -check 1"
feature option="use_null_move -check 1"
feature option="allow_king_capture -check 0"
feature option="singular_margin -spin 30 0 1000"
feature option="futility_margin -spin 125 0 1000"
feature option="montecarlo -check 1"
feature option="UCTK -spin 44 0 100"
feature option="UCTN -spin 10 1 1000000"
feature done=1
<000000000500>accepted done
<000000000500>accepted name
<000000000500>accepted myname
<000000000500>accepted sigint
<000000000500>accepted sigterm
<000000000500>accepted variants
<000000000500>accepted san
<000000000500>accepted usermove
<000000000500>accepted setboard
<000000000500>accepted draw
<000000000500>accepted colors
<000000000500>accepted smp
<000000000500>accepted memory
<000000000500>accepted egt
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted option
<000000000500>accepted done
<000000006734>option UCTK=60
<000000011297>new
<000000011328>random
<000000011328>variant suicide
setup (PNBRQ................Kpnbrq................k) 8x8+0 rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1
<000000011328>level 40 2 0
<000000011328>post
<000000011328>hard
<000000011328>easy
<000000011328>force
<000000011328>setboard rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1
<000000011359>computer
<000000011359>name NebiyuChess_1.2
Hello NebiyuChess_1.2!
<000000014515>time 12000
<000000014515>otim 11678
<000000014515>usermove g2g3
<000000014515>go
[st = 2813ms, mt = 59250ms , moves_left 40]
Time : 2844ms Tree : nodes 52664 depth 12 pps 33052 visits 94000
h7h6 0.45 388 869
h7h5 0.47 759 1632
g7g6 0.51 24287 47850
g7g5 0.50 6277 12616
f7f6 0.44 356 803
f7f5 0.44 294 673
e7e6 0.48 1563 3256
e7e5 0.46 711 1533
d7d6 0.48 1762 3656
d7d5 0.49 2293 4719
c7c6 0.48 1943 4018
c7c5 0.42 208 492
b7b6 0.48 2088 4308
b7b5 0.45 422 940
a7a6 0.45 502 1106
a7a5 0.46 574 1254
g8f6 0.45 475 1050
g8h6 0.46 683 1476
b8a6 0.44 330 748
b8c6 0.45 452 1001
<000000017359>move g7g6
<000000019609>time 11715
<000000019609>otim 11453
<000000019609>usermove g1h3
[st = 2816ms, mt = 57825ms , moves_left 39]
Time : 2875ms Tree : nodes 52664 depth 16 pps 34782 visits 100000
g6g5 0.53 42715 80285
h7h6 0.45 258 570
h7h5 0.47 366 785
f7f6 0.39 78 198
f7f5 0.44 184 419
e7e6 0.49 905 1842
e7e5 0.49 815 1667
d7d6 0.48 657 1359
d7d5 0.48 655 1355
c7c6 0.48 542 1134
c7c5 0.46 327 708
b7b6 0.48 595 1238
b7b5 0.48 630 1306
a7a6 0.40 87 219
a7a5 0.48 563 1175
g8f6 0.45 257 568
g8h6 0.50 1649 3276
b8a6 0.46 279 612
b8c6 0.42 124 296
f8g7 0.43 159 369
f8h6 0.46 283 619
<000000022484>move g6g5
<000000022562>time 11428
<000000022562>otim 11445
<000000022562>usermove h3g5
[st = 2818ms, mt = 56390ms , moves_left 38]
Time : 2844ms Tree : nodes 52664 depth 13 pps 37271 visits 106000
h7h6 0.54 9629 17886
h7h5 0.52 2608 4971
f7f6 0.52 1520 2946
f7f5 0.51 1426 2771
e7e6 0.53 3555 6724
e7e5 0.51 1074 2110
d7d6 0.51 1000 1970
d7d5 0.52 1574 3047
c7c6 0.53 3991 7530
c7c5 0.50 778 1551
b7b6 0.52 1912 3678
b7b5 0.52 1943 3735
a7a6 0.54 10471 19423
a7a5 0.52 2489 4751
g8f6 0.51 1044 2053
g8h6 0.52 1721 3322
b8a6 0.51 1199 2345
b8c6 0.51 1397 2716
f8g7 0.53 4334 8163
f8h6 0.52 2251 4308
<000000025406>move a7a6
<000000027640>time 11143
<000000027640>otim 11222
<000000027640>usermove g5f7
[st = 2822ms, mt = 54965ms , moves_left 37]
Time : 1ms Tree : nodes 52664 depth 0 pps 0 visits 0
e8f7 -1.#J 0 0
<000000027640>move e8f7
<000000030656>time 11134
<000000030656>otim 10929
<000000030656>usermove b1a3
[st = 2898ms, mt = 54920ms , moves_left 36]
Time : 2906ms Tree : nodes 52664 depth 14 pps 39573 visits 115000
h7h6 0.42 2821 6709
h7h5 0.41 1600 3877
a6a5 0.39 553 1415
e7e6 0.41 1410 3434
e7e5 0.41 1159 2848
d7d6 0.41 1157 2842
d7d5 0.42 2457 5867
c7c6 0.43 4225 9940
c7c5 0.39 458 1188
b7b6 0.43 4683 10989
b7b5 0.42 2885 6855
g8f6 0.42 3564 8420
g8h6 0.42 2316 5540
b8c6 0.40 855 2131
f8g7 0.38 365 962
f8h6 0.40 721 1815
a8a7 0.42 2329 5570
d8e8 0.42 3102 7357
f7e6 0.42 2904 6900
f7e8 0.42 2453 5858
f7g6 0.42 1901 4577
f7f6 0.42 2208 5290
f7g7 0.42 1917 4616
<000000033578>move b7b6
<000000036515>time 10842
<000000036515>otim 10636
<000000036515>usermove a3b5
[st = 2901ms, mt = 53460ms , moves_left 35]
Time : 1ms Tree : nodes 52664 depth 0 pps 0 visits 0
a6b5 -1.#J 0 0
<000000036515>move a6b5
<000000039578>time 10831
<000000039578>otim 10340
<000000039578>usermove c2c4
[st = 2983ms, mt = 53405ms , moves_left 34]
Time : 3000ms Tree : nodes 58038 depth 17 pps 45333 visits 136000
b5c4 0.08 5441 66535
a8a2 0.08 5684 69465
<000000042578>move a8a2
<000000044953>time 10531
<000000044953>otim 10103
<000000044953>usermove a1a2
[st = 2987ms, mt = 51905ms , moves_left 33]
Time : 1ms Tree : nodes 58038 depth 0 pps 0 visits 0
b5c4 -1.#J 0 0
<000000044953>move b5c4
<000000047453>time 10523
<000000047453>otim 9861
<000000047453>usermove d1b3
[st = 3078ms, mt = 51865ms , moves_left 32]
Time : 1ms Tree : nodes 58038 depth 0 pps 0 visits 0
c4b3 -1.#J 0 0
<000000047453>move c4b3
<000000050531>time 10513
<000000050531>otim 9562
<000000050531>usermove a2a5
[st = 3174ms, mt = 51815ms , moves_left 31]
Time : 1ms Tree : nodes 58038 depth 0 pps 0 visits 0
b6a5 -1.#J 0 0
<000000050531>move b6a5
<000000053625>time 10503
<000000053625>otim 9264
<000000053625>usermove e1d1
[st = 3278ms, mt = 51765ms , moves_left 30]
Time : 3297ms Tree : nodes 89564 depth 10 pps 53078 visits 175000
a5a4 0.10 1216 12097
h7h6 0.09 572 6159
h7h5 0.09 614 6554
e7e6 0.11 2217 21087
e7e5 0.10 1036 10456
d7d6 0.08 242 2982
d7d5 0.09 401 4529
c7c6 0.10 759 7906
c7c5 0.09 546 5910
g8f6 0.08 269 3250
g8h6 0.08 306 3608
b8a6 0.09 559 6037
b8c6 0.10 883 9047
f8g7 0.09 640 6797
f8h6 0.09 563 6075
c8b7 0.04 31 731
c8a6 0.10 811 8387
d8e8 0.10 714 7483
f7e6 0.10 1295 12809
f7e8 0.10 832 8582
f7g6 0.10 867 8905
f7f6 0.10 817 8438
f7g7 0.09 680 7171
<000000056922>move e7e6
<000000064734>time 10173
<000000064734>otim 8483
<000000064734>usermove d1c2
[st = 3283ms, mt = 50115ms , moves_left 29]
Time : 1ms Tree : nodes 89564 depth 0 pps 0 visits 0
b3c2 -1.#J 0 0
<000000064734>move b3c2
<000000068047>time 10165
<000000068047>otim 8159
<000000068047>usermove h2h4
[st = 3397ms, mt = 50075ms , moves_left 28]
Time : 1ms Tree : nodes 89564 depth 0 pps 0 visits 0
d8h4 -1.#J 0 0
<000000068047>move d8h4
<000000070953>time 10157
<000000070953>otim 7876
<000000070953>usermove g3h4
[st = 3520ms, mt = 50035ms , moves_left 27]
Time : 3547ms Tree : nodes 89564 depth 20 pps 51310 visits 182000
e6e5 0.11 35 317
a5a4 0.13 60 465
h7h6 0.09 20 225
h7h5 0.12 41 353
d7d6 0.08 17 209
d7d5 0.11 32 299
c7c6 0.12 50 405
c7c5 0.08 15 196
g8e7 0.11 37 332
g8f6 0.12 49 399
g8h6 0.12 51 413
b8a6 0.13 52 419
b8c6 0.08 18 212
f8e7 0.10 26 266
f8d6 0.12 47 388
f8c5 0.11 33 305
f8b4 0.16 184 1124
f8a3 0.32 55168 172139
f8g7 0.16 148 935
f8h6 0.11 31 293
c8b7 0.05 6 130
c8a6 0.13 52 419
f7e8 0.13 52 416
f7g6 0.11 34 314
f7f6 0.13 60 462
f7g7 0.10 26 266
f7e7 0.11 32 299
<000000074500>move f8a3
<000000074609>time 9803
<000000074609>otim 7865
<000000074609>usermove b2a3
[st = 3526ms, mt = 48265ms , moves_left 26]
Time : 3563ms Tree : nodes 89564 depth 23 pps 55290 visits 197000
e6e5 0.19 228 1191
a5a4 0.21 553 2630
h7h6 0.22 747 3468
h7h5 0.22 761 3528
d7d6 0.19 253 1306
d7d5 0.19 198 1054
c7c6 0.20 355 1761
c7c5 0.19 253 1304
g8e7 0.22 811 3743
g8f6 0.19 231 1206
g8h6 0.23 4252 18123
b8a6 0.20 403 1971
b8c6 0.20 405 1982
c8b7 0.10 17 174
c8a6 0.19 197 1049
f7e8 0.21 439 2132
f7g6 0.29 40271 138767
f7f8 0.21 420 2048
f7f6 0.21 632 2970
f7g7 0.22 982 4474
f7e7 0.21 436 2119
<000000078187>move f7g6
<000000084531>time 9445
<000000084531>otim 7231
<000000084531>usermove e2e3
[st = 3532ms, mt = 46475ms , moves_left 25]
Time : 3562ms Tree : nodes 89564 depth 24 pps 73273 visits 261000
e6e5 0.16 10 61
a5a4 0.17 11 66
h7h6 0.25 39 158
h7h5 0.16 9 59
d7d6 0.00 0 20
d7d5 0.20 16 83
c7c6 0.21 19 92
c7c5 0.23 29 126
g8e7 0.25 39 157
g8f6 0.16 9 57
g8h6 0.17 11 66
b8a6 0.18 12 70
b8c6 0.19 14 77
c8b7 0.07 2 29
c8a6 0.24 36 147
g6f5 0.23 27 120
g6f7 0.21 20 95
g6h5 0.02 0 23
g6g7 0.22 22 104
g6g5 0.95 245617 259184
g6h6 0.21 21 99
g6f6 0.22 23 107
<000000088093>move g6g5
<000000088172>time 9089
<000000088172>otim 7223
<000000088172>usermove h4g5
[st = 3537ms, mt = 44695ms , moves_left 24]
Time : 3562ms Tree : nodes 89564 depth 24 pps 82257 visits 293000
e6e5 0.34 60 179
a5a4 0.31 40 129
h7h6 0.21 10 47
h7h5 0.09 2 22
d7d6 0.21 10 49
d7d5 0.25 16 64
c7c6 0.22 11 50
c7c5 0.27 21 78
g8e7 0.15 4 30
g8f6 0.95 276009 289107
g8h6 0.43 1177 2717
b8a6 0.30 31 105
b8c6 0.35 72 209
c8b7 0.30 32 107
c8a6 0.30 32 107
<000000091734>move g8f6
<000000094234>time 8732
<000000094234>otim 6973
<000000094234>usermove h1h7
[st = 3544ms, mt = 42910ms , moves_left 23]
Time : 3563ms Tree : nodes 89564 depth 26 pps 89250 visits 318000
f6h7 0.18 4 22
h8h7 0.95 301268 317978
<000000097797>move h8h7
<000000097875>time 8376
<000000097875>otim 6965
<000000097875>usermove g5f6
[st = 3552ms, mt = 41130ms , moves_left 22]
Time : 3578ms Tree : nodes 91015 depth 21 pps 96981 visits 347000
e6e5 0.33 6 20
a5a4 0.35 7 20
d7d6 0.42 14 33
d7d5 0.00 0 6
c7c6 0.41 11 28
c7c5 0.00 0 6
b8a6 0.36 7 21
b8c6 0.51 30 59
c8b7 0.42 13 32
c8a6 0.18 2 11
h7h8 0.21 2 12
h7h6 0.15 1 10
h7h5 0.41 11 28
h7h4 0.49 25 51
h7h3 0.51 30 59
h7h2 0.18 2 11
h7h1 0.15 1 10
h7g7 0.67 464 690
h7f7 0.41 11 28
h7e7 0.97 334581 345865
<000000101453>move h7e7
<000000101547>time 8018
<000000101547>otim 6956
<000000101547>usermove f6e7
[st = 3558ms, mt = 39340ms , moves_left 21]
Time : 3578ms Tree : nodes 91015 depth 18 pps 128842 visits 461000
e6e5 0.67 153 230
a5a4 0.61 67 110
d7d6 0.98 449583 457547
d7d5 0.71 422 594
c7c6 0.70 288 414
c7c5 0.71 364 516
b8a6 0.71 431 606
b8c6 0.72 504 704
c8b7 0.67 169 252
c8a6 0.44 12 27
<000000105125>move d7d6
<000000108000>time 7660
<000000108000>otim 6668
<000000108000>usermove e7e8q
[st = 3567ms, mt = 37550ms , moves_left 20]
Time : 3593ms Tree : nodes 91015 depth 18 pps 158363 visits 569000
d6d5 0.66 30 46
e6e5 0.63 24 38
a5a4 0.61 20 33
c7c6 0.56 15 27
c7c5 0.54 13 24
b8a6 0.82 314 383
b8d7 0.71 49 69
b8c6 0.67 34 51
c8b7 0.99 563577 568247
c8a6 0.57 16 29
c8d7 0.68 36 53
<000000111593>move c8b7
<000000114312>time 7301
<000000114312>otim 6396
<000000114312>usermove e8b8
[st = 3574ms, mt = 35755ms , moves_left 19]
Time : 3578ms Tree : nodes 91015 depth 17 pps 200670 visits 718000
e6e5 0.94 1483 1575
d6d5 0.97 7539 7776
a5a4 0.97 5740 5940
c7c6 0.95 2262 2378
c7c5 0.97 6460 6675
b7c8 1.00 680938 684278
b7a6 0.92 676 738
b7a8 0.95 2052 2162
b7c6 0.94 1460 1551
b7d5 0.92 717 781
b7e4 0.92 662 723
b7f3 0.93 1005 1080
b7g2 0.91 616 675
b7h1 0.94 1573 1668
<000000117906>move b7c8
<000000121062>result 0-1 {White resigns}

[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1"]

1.g2g3 g7g6 2.g1h3 g6g5 3.h3g5 a7a6 4.g5f7 e8f7 5.b1a3 b7b6 6.a3b5 a6b5 7.c2c4 a8a2 8.a1a2 b5c4
9.d1b3 c4b3 10.a2a5 b6a5 11.e1d1 e7e6 12.d1c2 b3c2 13.h2h4 d8h4 14.g3h4 f8a3 15.b2a3 f7g6 16.e2e3 g6g5
17.h4g5 g8f6 18.h1h7 h8h7 19.g5f6 h7e7 20.f6e7 d7d6 21.e7e8Q c8b7 22.e8b8 b7c8

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1
rnbqkbnr/pppppppp/8/8/8/6P1/PPPPPP1P/RNBQKBNR b - - 0 1
rnbqkbnr/pppppp1p/6p1/8/8/6P1/PPPPPP1P/RNBQKBNR w - - 0 2
rnbqkbnr/pppppp1p/6p1/8/8/6PN/PPPPPP1P/RNBQKB1R b - - 1 2
rnbqkbnr/pppppp1p/8/6p1/8/6PN/PPPPPP1P/RNBQKB1R w - - 0 3
rnbqkbnr/pppppp1p/8/6N1/8/6P1/PPPPPP1P/RNBQKB1R b - - 0 3
rnbqkbnr/1ppppp1p/p7/6N1/8/6P1/PPPPPP1P/RNBQKB1R w - - 0 4
rnbqkbnr/1ppppN1p/p7/8/8/6P1/PPPPPP1P/RNBQKB1R b - - 0 4
rnbq1bnr/1ppppk1p/p7/8/8/6P1/PPPPPP1P/RNBQKB1R w - - 0 5
rnbq1bnr/1ppppk1p/p7/8/8/N5P1/PPPPPP1P/R1BQKB1R b - - 1 5
rnbq1bnr/2pppk1p/pp6/8/8/N5P1/PPPPPP1P/R1BQKB1R w - - 0 6
rnbq1bnr/2pppk1p/pp6/1N6/8/6P1/PPPPPP1P/R1BQKB1R b - - 1 6
rnbq1bnr/2pppk1p/1p6/1p6/8/6P1/PPPPPP1P/R1BQKB1R w - - 0 7
rnbq1bnr/2pppk1p/1p6/1p6/2P5/6P1/PP1PPP1P/R1BQKB1R b - c3c4 0 7
1nbq1bnr/2pppk1p/1p6/1p6/2P5/6P1/rP1PPP1P/R1BQKB1R w - - 0 8
1nbq1bnr/2pppk1p/1p6/1p6/2P5/6P1/RP1PPP1P/2BQKB1R b - - 0 8
1nbq1bnr/2pppk1p/1p6/8/2p5/6P1/RP1PPP1P/2BQKB1R w - - 0 9
1nbq1bnr/2pppk1p/1p6/8/2p5/1Q4P1/RP1PPP1P/2B1KB1R b - - 1 9
1nbq1bnr/2pppk1p/1p6/8/8/1p4P1/RP1PPP1P/2B1KB1R w - - 0 10
1nbq1bnr/2pppk1p/1p6/R7/8/1p4P1/1P1PPP1P/2B1KB1R b - - 1 10
1nbq1bnr/2pppk1p/8/p7/8/1p4P1/1P1PPP1P/2B1KB1R w - - 0 11
1nbq1bnr/2pppk1p/8/p7/8/1p4P1/1P1PPP1P/2BK1B1R b - - 1 11
1nbq1bnr/2pp1k1p/4p3/p7/8/1p4P1/1P1PPP1P/2BK1B1R w - - 0 12
1nbq1bnr/2pp1k1p/4p3/p7/8/1p4P1/1PKPPP1P/2B2B1R b - - 1 12
1nbq1bnr/2pp1k1p/4p3/p7/8/6P1/1PpPPP1P/2B2B1R w - - 0 13
1nbq1bnr/2pp1k1p/4p3/p7/7P/6P1/1PpPPP2/2B2B1R b - h3h4 0 13
1nb2bnr/2pp1k1p/4p3/p7/7q/6P1/1PpPPP2/2B2B1R w - - 0 14
1nb2bnr/2pp1k1p/4p3/p7/7P/8/1PpPPP2/2B2B1R b - - 0 14
1nb3nr/2pp1k1p/4p3/p7/7P/b7/1PpPPP2/2B2B1R w - - 1 15
1nb3nr/2pp1k1p/4p3/p7/7P/P7/2pPPP2/2B2B1R b - - 0 15
1nb3nr/2pp3p/4p1k1/p7/7P/P7/2pPPP2/2B2B1R w - - 1 16
1nb3nr/2pp3p/4p1k1/p7/7P/P3P3/2pP1P2/2B2B1R b - - 0 16
1nb3nr/2pp3p/4p3/p5k1/7P/P3P3/2pP1P2/2B2B1R w - - 1 17
1nb3nr/2pp3p/4p3/p5P1/8/P3P3/2pP1P2/2B2B1R b - - 0 17
1nb4r/2pp3p/4pn2/p5P1/8/P3P3/2pP1P2/2B2B1R w - - 1 18
1nb4r/2pp3R/4pn2/p5P1/8/P3P3/2pP1P2/2B2B2 b - - 0 18
1nb5/2pp3r/4pn2/p5P1/8/P3P3/2pP1P2/2B2B2 w - - 0 19
1nb5/2pp3r/4pP2/p7/8/P3P3/2pP1P2/2B2B2 b - - 0 19
1nb5/2ppr3/4pP2/p7/8/P3P3/2pP1P2/2B2B2 w - - 1 20
1nb5/2ppP3/4p3/p7/8/P3P3/2pP1P2/2B2B2 b - - 0 20
1nb5/2p1P3/3pp3/p7/8/P3P3/2pP1P2/2B2B2 w - - 0 21
1nb1Q3/2p5/3pp3/p7/8/P3P3/2pP1P2/2B2B2 b - - 0 21
1n2Q3/1bp5/3pp3/p7/8/P3P3/2pP1P2/2B2B2 w - - 1 22
1Q6/1bp5/3pp3/p7/8/P3P3/2pP1P2/2B2B2 b - - 0 22


<000000121093>force

[Vladimir Xern]

Quality of montecarlo playouts in standard chess is very hard to improve it seems. It is full of tactics that I couldn't improve even after using SEE and other tactical staff related to checking. Suicide chess variants however sound like good candidates for UCT. They are more like checkers in the following ways

- forced nature of captures
- king is like any other piece

This signicantly improved the use of UCT in "chess" I am getting good results but the alpha-beta engine is too strong currently. It hasn't even lost a game.

That's interesting. Suicide chess has generally been the domain of proof number search and its variants, and I've wondered how something like Monte-Carlo proof number search would perform. Writing an evaluation function for suicide chess has always been somewhat nebulous, and I think alpha-beta has a hard time catching the far-off zugzwangs that can happen in many positions.

I also wonder how other domain-independent approaches would fare, such as Ulf Lorenz's controlled conspiracy number search.

[Daniel Shawul]

Oh I didn't actually know PN search is the preferred method there. I know it is used in GO to resolve life and death situations. Anyways from the games I observed so far suicide chess seems to have narrower tree than even checkers, once the captures start. The alpha beta engine usually sees a mate once the rook is out of the back rank ! I have never played suicide games before though. About zugzwangs, I disable nullmove search to any game with forced capture rules such as checkers and suicide chess. I don't use stand pat in qsearch as well. However I don't use qsearch for suicide chess. It explodes the tree a lot. Just eval() is far better. Alpha-beta seems to be good already searching to a depth of 24 in the opening position.
Thanks for the hint about PN search.

[Daniel Shawul]

Yuk. This game is almost solved. http://catalin.francu.com/nilatac/book.php?query= . Now I can see why PN search is preferred.

[Vladimir Xern]

To be fair, most of the strong suicide engines seem to use alpha-beta, PN, and PN^2 searches at the same time. For example, a shallow PN search is good at finding immediately losing or winning forced lines, and alpha-beta for general game play. Nilatac, for example, uses all three, but its weaker brother Catnail is roughly 1900 on FICS using just a brief PN search and no alpha-beta.

There are also some strong suicide engines, such as SelfKiller, that seem to only use alpha-beta. Like I said, the trickiest part with suicide chess is writing a good evaluation. I believe Ben Nye (a.k.a angrim, author of the strongest suicide chess engine) once said that any time investment in advanced search tricks or SMP is almost pointless compared to working on the eval.

At any rate, I'm very interested in how your approach progresses. I have a feeling that a Monte-Carlo search might be good in positions such as the following, where the strategic goal is to restrict the opponent's pieces until finally, zugzwang. I'm also really curious how UCT will perform in atomic chess as well. I know of no strong atomic engines available to test against, but at least there's Sjeng for suicide.

[D]r1b3n1/p1kp2p1/4n3/8/8/4P3/PPPP1PP1/R1B1K1N1 w - - 0 1

[Daniel Shawul]

I just did atomic chess using 'no check' rules just for fun. But I am more or less certain that UCT will not work there since captures are not forced, and rules are exactly same as orthodox except for the explostions. Game should end quicker though.

Nebiyu seems to have problems with the position. It is changing its mind a lot. What is the best move btw? alpha-beta says e1e2, and Uct g1h3

Code: Select all

            
variant suicide
setup (PNBRQ................Kpnbrq................k) 8x8+0 rnbqkbnr/pppppppp/8/8
/8/8/PPPPPPPP/RNBQKBNR w - - 0 1
setboard r1b3n1/p1kp2p1/4n3/8/8/4P3/PPPP1PP1/R1B1K1N1 w - - 0 1
d

            a b c d e f g h
            * * * * * * * * * * * * * * * * * * * * * * * *
            * * * * * * * * * * * * * * * * * * * * * * * *
            * * * * * * * * * * * * * * * * * * * * * * * *
            * * * * * * * * * * * * * * * * * * * * * * * *
          8 r . b . . . n . * * * * * * * * * * * * * * * * 8
          7 p . k p . . p . * * * * * * * * * * * * * * * * 7
          6 . . . . n . . . * * * * * * * * * * * * * * * * 6
          5 . . . . . . . . * * * * * * * * * * * * * * * * 5
          4 . . . . . . . . * * * * * * * * * * * * * * * * 4
          3 . . . . P . . . * * * * * * * * * * * * * * * * 3
          2 P P P P . P P . * * * * * * * * * * * * * * * * 2
          1 R . B . K . N . * * * * * * * * * * * * * * * * 1
            * * * * * * * * * * * * * * * * * * * * * * * *
            * * * * * * * * * * * * * * * * * * * * * * * *
            * * * * * * * * * * * * * * * * * * * * * * * *
            * * * * * * * * * * * * * * * * * * * * * * * *
            a b c d e f g h

        r1b3n1/p1kp2p1/4n3/8/8/4P3/PPPP1PP1/R1B1K1N1 w - - 0 1

analyze
2 -5 0 98  f2f4 e6f4
3 -185 0 584  e3e4 d7d5 e4d5
4 -210 0 666  e3e4 d7d5 e4d5 g8e7
5 -500 0 679  e3e4
5 -500 0 692  e3e4 d7d5 e4d5 g8e7 d5e6
5 -370 1 953  g1e2 e6d4 e3d4 g8e7 b2b4
5 -365 1 1148  e1e2 e6d4 e3d4 g8e7 g1f3
5 -365 1 1744  e1e2 e6d4 e3d4 g8e7 g1f3
6 -370 1 2137  e1e2 e6d4 e3d4 g7g6 g1f3 g8e7
6 -315 1 2160  g1e2
6 -100 1 2263  g1e2
6 -100 1 2773  g1e2 g8e7 e2d4 e6d4 e3d4 g7g5
6 -100 3 2799  g1e2 g8e7 e2d4 e6d4 e3d4 g7g5
7 -85 3 2998  g1e2 g8e7 e2d4 e6d4 e3d4 g7g5 e1e2
7 -85 3 3167  g1e2 g8e7 e2d4 e6d4 e3d4 g7g5 e1e2
8 -350 3 3656  g1e2 g8e7 e2d4 e6d4 e3d4 e7g8 e1e2 g8e7
8 -370 3 8280  g1e2 e6d4 e3d4 a7a6 g2g4 g7g6 b2b4 g8e7
8 -115 4 28449  e3e4 e6d8 g1f3 g8e7 f3e5 c8b7 e5d7 b7e4
8 -115 4 34270  e3e4 e6d8 g1f3 g8e7 f3e5 c8b7 e5d7 b7e4
9 -100 4 34529  e3e4 e6d8 g1f3 g8e7 f3e5 c8b7 e5d7 b7e4 e1e2
9 -100 6 35395  e3e4 e6d8 g1f3 g8e7 f3e5 c8b7 e5d7 b7e4 e1e2
10 -150 6 37829  e3e4
10 -485 6 38709  e3e4 e6d8 g1f3 g8e7 f3g5 d8e6 g5e6 d7e6 e1e2 c8d7
10 -405 6 40313  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 g8e7 g1f3 c8d7
10 -295 6 45238  g1h3 e6g5 h3g5 c7c6 g2g4 a8b8 g5e6 b8b2 e6g7 b2c2
10 -295 9 158456  g1h3 e6g5 h3g5 c7c6 g2g4 a8b8 g5e6 b8b2 e6g7 b2c2
11 -345 10 159448  g1h3
11 -280 10 168522  g1h3 e6g5 h3g5 g8e7 e1e2 e7d5 g5e6 d5e3 e6g7 e3c2 g7e6
11 -280 10 168793  g1h3 e6g5 h3g5 g8e7 e1e2 e7d5 g5e6 d5e3 e6g7 e3c2 g7e6
12 -330 10 169249  g1h3
12 -285 12 174540  g1h3 e6g5 h3g5 g7g6 e1e2 g8e7 d2d4 e7f5 g5e6 f5d4 e3d4 d7e6
12 -230 12 175493  e3e4
12 -295 14 213043  e3e4 e6d8 g1h3 g8e7 h3g5 d8e6 g5e6 d7e6 e1e2 e7d5 e4d5 e6d5
12 -285 14 213245  g1h3 e6g5 h3g5 g7g6 e1e2 g8e7 d2d4 e7f5 g5e6 f5d4 e3d4 d7e6
12 -285 14 214337  g1h3 e6g5 h3g5 g7g6 e1e2 g8e7 d2d4 e7f5 g5e6 f5d4 e3d4 d7e6
13 -335 15 219775  g1h3
13 -235 15 229402  g1h3
13 -290 15 237080  g1h3 e6g5 h3g5 c7c6 g2g4 g7g6 e1e2 g8h6 g5f3 h6g4 f3e5 g4e3 e
5d7
13 110 18 350740  f2f4
13 -535 20 353639  f2f4
13 -695 20 357259  f2f4 e6f4 e3f4 g7g5 f4g5 g8f6 g5f6 c7d6 f6f7 d6c6 d2d4 a7a5 g
1f3
13 -215 25 545268  b2b4 g7g6 d2d3 g8e7 a1b1 e7d5 b1a1 d5b4 f2f4 b4a2 a1a2 e6f4 a
2a7
13 -215 25 545395  b2b4 g7g6 d2d3 g8e7 a1b1 e7d5 b1a1 d5b4 f2f4 b4a2 a1a2 e6f4 a
2a7
14 -165 25 548121  b2b4
14 -205 26 571342  b2b4 g7g6 d2d3 g8e7 c1a3 c7d6 g1e2 e7d5 f2f4 e6f4 e2f4 d5e3 f
4g6 e3c2
14 -100 29 670422  g1h3 e6d8 h3g5 d8e6 g5e6 d7e6 a1b1 g8e7 b2b3 c7c6 e1e2 c8d7 b
1b2 a8d8
14 -100 29 670898  g1h3 e6d8 h3g5 d8e6 g5e6 d7e6 a1b1 g8e7 b2b3 c7c6 e1e2 c8d7 b
1b2 a8d8
15 -350 31 680853  g1h3 e6d8 h3g5 d8e6 g5e6 d7e6 a1b1 g8e7 f2f3 a7a6 e1e2 g7g5 f
3f4 g5f4 e3f4
15 -550 31 707010  g1h3 e6d8 h3g5 d8e6 g5e6 d7e6 a1b1 g8e7 f2f3 a7a6 e1e2 g7g5 f
3f4 g5f4 e3f4
15 -485 32 717518  g1h3 e6d4 e3d4 c7b6 e1d1 a7a6 c2c3 g8e7 d4d5 e7d5 h3g5 d5c3 b
2c3 d7d5 d1e2
15 -295 40 964116  e3e4 e6d8 a2a3 g8e7 f2f4 c7d6 a1b1 g7g5 f4g5 e7d5 e4d5 d6d5 d
2d4 d5d4 g1f3
15 -55 60 1724341  a2a3 e6d8 g1e2 d8b7 a1b1 c7c6 e2g3 a7a6 e1e2 a8b8 d2d3 c6d6 a
3a4 g8e7 c1d2
15 -55 60 1728397  a2a3 e6d8 g1e2 d8b7 a1b1 c7c6 e2g3 a7a6 e1e2 a8b8 d2d3 c6d6 a
3a4 g8e7 c1d2
16 -350 64 1838441  a2a3 e6d8 g1e2 d8b7 a1b1 c7c6 e2g3 a7a6 e1e2 a8b8 d2d3 a6a5
b2b4 a5b4 b1b4 g8e7
16 -550 65 1840958  a2a3 e6d8 g1e2 d8b7 a1b1 c7c6 e2g3 a7a6 e1e2 a8b8 d2d3 a6a5
b2b4 a5b4 b1b4 g8e7
16 -750 65 1841343  a2a3 e6d8 g1e2 d8b7 a1b1 c7c6 e2g3 a7a6 e1e2 a8b8 d2d3 a6a5
b2b4 a5b4 b1b4 g8e7
16 -780 67 1876822  a2a3 e6f4 e3f4 g7g5 f4g5 g8f6 g5f6 c7c6 g1f3 a7a6 g2g4 c8b7
a1b1 a8b8 e1e2 d7d5
16 -385 68 1914025  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 g8e7 a2a4 e6d7 a1b1 g7g6
a4a5 a7a6 g1f3 e7d5
16 -85 101 3165479  b2b3 e6d8 d2d4 c7c6 e1e2 c6c7 e2f1 c7b6 b3b4 g8f6 g2g4 f6g4
b4b5 g4e3 c1e3 b6b5
16 -85 101 3177653  b2b3 e6d8 d2d4 c7c6 e1e2 c6c7 e2f1 c7b6 b3b4 g8f6 g2g4 f6g4
b4b5 g4e3 c1e3 b6b5
17 -135 106 3330041  b2b3 e6d8 d2d4 c7c6 e1e2 c6c7 g2g4 a7a6 c1b2 d8b7 d4d5 g8e7
 b2g7 e7d5 a1d1 d5e3 d1d7
17 -335 106 3333774  b2b3 e6d8 d2d4 c7c6 e1e2 c6c7 g2g4 a7a6 c1b2 d8b7 d4d5 g8e7
 b2g7 e7d5 a1d1 d5e3 d1d7
17 -535 112 3528575  b2b3 e6d8 d2d4 c7c6 e1e2 c6c7 g2g4 a7a6 c1b2 d8b7 d4d5 g8e7
 b2g7 e7d5 a1d1 d5e3 d1d7
17 -735 112 3530023  b2b3 e6d8 d2d4 c7c6 e1e2 c6c7 g2g4 a7a6 c1b2 d8b7 d4d5 g8e7
 b2g7 e7d5 a1d1 d5e3 d1d7
17 -775 115 3588222  b2b3 e6f4 e3f4 g7g5 f4g5 g8f6 g5f6 c7c6 g1f3 a7a6 f6f7 a8a7
 e1e2 a7c7 d2d4 d7d5 c1f4
17 -395 118 3691028  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 a8a7 e2e3 g8e7
 g1e2 g7g6 a1b1 a7d7 f2f4
17 -395 132 4201625  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 a8a7 e2e3 g8e7
 g1e2 g7g6 a1b1 a7d7 f2f4
18 -385 132 4217697  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 a8a7 e2e3 g8e7
 g1e2 g7g6 a1b1 e6d7 f2f4 a7c7
18 -385 134 4218550  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 a8a7 e2e3 g8e7
 g1e2 g7g6 a1b1 e6d7 f2f4 a7c7
19 -375 135 4273588  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 e7g6
 e3e2 g6f8 e2e3 f8d7 g1e2 g7g5 b2b4
19 -375 137 4327028  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 e7g6
 e3e2 g6f8 e2e3 f8d7 g1e2 g7g5 b2b4
20 -370 139 4367666  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 g8e7 a3d3 a7d7
20 -370 142 4468292  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 g8e7 a3d3 a7d7
21 -370 143 4482213  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 g8e7 a4a5 a7d7 a3d3
21 -370 148 4596257  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 g8e7 a4a5 a7d7 a3d3
22 -360 153 4785990  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 g8e7 a4a5 e6d7 a3d3 a7c7
22 -360 160 5030671  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 g8e7 a4a5 e6d7 a3d3 a7c7
23 -370 162 5057974  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 a7g7 a4a5 g8e7 b2b4 c8d7 a3d3
23 -370 179 5509459  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 a7g7 a4a5 g8e7 b2b4 c8d7 a3d3
24 -365 182 5581516  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 a7g7 c2c3 g8e7 a4a5 e7g8 a3b3 g8e7
24 -365 184 5603370  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 a7g7 c2c3 g8e7 a4a5 e7g8 a3b3 g8e7
25 -365 185 5658263  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 a7g7 b2b3 g8e7 c2c3 e7g8 a4a5 g8e7 d2d4
25 -365 198 6104010  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 f2f3 a7g7 b2b3 g8e7 c2c3 e7g8 a4a5 g8e7 d2d4
26 -365 204 6306089  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 c2c3 a7g7 b2b3 g8e7 c1b2 g7g8 b2c1 e6d7 f2f4 g8g7
26 -365 217 6673432  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a8a7
 g1e2 g7g6 a1a3 e7g8 c2c3 a7g7 b2b3 g8e7 c1b2 g7g8 b2c1 e6d7 f2f4 g8g7
27 -360 243 7648576  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a6a5
 e3e2 a8a7 a1b1 g7g6 e2e3 e7g8 e3e2 e6d7 g2g4 a7a6 g1f3 g8e7 b2b4 a5b4 b1b4
27 -360 273 8702539  e3e4 d7d5 e4d5 c7d6 d5e6 d6e6 e1e2 a7a6 a2a4 g8e7 e2e3 a6a5
 e3e2 a8a7 a1b1 g7g6 e2e3 e7g8 e3e2 e6d7 g2g4 a7a6 g1f3 g8e7 b2b4 a5b4 b1b4
28 -410 343 11203857  e3e4
28 -610 343 11205025  e3e4
28 -810 343 11206157  e3e4
28 -1010 345 11207334  e3e4
29 -1620 393 12932606  e3e4 d7d5 e4d5 c8a6 d5e6 c7d7 e6d7 a6d3 c2d3 g7g5 d7d8N a
8d8 a2a4 d8d3 a1a3 d3a3 b2a3 g8e7 g1e2 g5g4 f2f4 g4f3 g2f3 a7a5 d2d4 e7c8 e2f4 c
8d6 c1e3
29 -690 732 24523240  b2b3 e6f4 e3f4 g7g5 f4g5 g8f6 g5f6 c7d6 f6f7 d6c6 g1f3 a7a
6 d2d4 c6b6 c1f4 a6a5 g2g4 b6a6 f4d6 a8a7 b3b4 a5b4 d6b4 a7c7 b4a3 c7c2 f3e5 c2f
2 e5d7
29 -385 2410 86249172  c2c3 e6d4 c3d4 c7b6 b2b3 g7g5 g2g3 g8e7 e1e2 b6c6 e2d3 c6
d6 d4d5 d6d5 a1b1 d5c5 f2f3 a7a5 b1a1 e7d5 b3b4 a5b4 d3d4 d5e3 d2e3 c5d4 e3d4 a8
a2 c1g5
29 -110 6475 225164710  a2a4 g8e7 e1e2 g7g5 d2d3 c7c6 a1b1 c6c5 f2f3 e7g8 e2e1 c
5c6 c2c4 g8e7 c4c5 c6c5 b2b3 a7a5 e1d2 e7d5 f3f4 d5f4 e3f4 g5f4 b3b4 a5b4 b1b4 a
8a4 b4f4
29 -110 6525 226736971  a2a4 g8e7 e1e2 g7g5 d2d3 c7c6 a1b1 c6c5 f2f3 e7g8 e2e1 c
5c6 c2c4 g8e7 c4c5 c6c5 b2b3 a7a5 e1d2 e7d5 f3f4 d5f4 e3f4 g5f4 b3b4 a5b4 b1b4 a
8a4 b4f4
30 -160 6890 238926704  a2a4
30 -360 6890 238947757  a2a4
30 -560 6893 239011258  a2a4
30 -760 6934 240242388  a2a4
30 -960 7006 242533064  a2a4
30 -935 7495 259347119  a2a4 e6f4 e3f4 g7g5 f4g5 c7c6 a4a5 c6c7 a5a6 c8a6 a1a6 g
8f6 a6a7 a8a7 g5f6 a7a3 b2a3 c7c6 f6f7 c6b6 g1f3 b6c7 f3e5 c7c6 e5d7 c6d7 c2c4 d
7d8 e1e2 d8e7
30 -345 11473 399380348  c2c3 e6d4 e3d4 c7d8 b2b4 d8e7 d4d5 e7f7 e1e2 f7f6 c3c4
f6f7 c1a3 g7g6 e2e1 f7f6 a1c1 f6g7 g1e2 g7f7 c1d1 f7f6 d2d3 f6g7 e2c1 g7f8 c1e2
a7a5 b4a5 a8a5
30 -345 13215 458543090  c2c3 e6d4 e3d4 c7d8 b2b4 d8e7 d4d5 e7f7 e1e2 f7f6 c3c4
f6f7 c1a3 g7g6 e2e1 f7f6 a1c1 f6g7 g1e2 g7f7 c1d1 f7f6 d2d3 f6g7 e2c1 g7f8 c1e2
a7a5 b4a5 a8a5
31 -295 14542 502622555  c2c3
31 -295 14665 506746057  c2c3 e6d4 e3d4 c7d8 b2b4 d8e7 g2g4 g7g5 e1e2 e7d8 e2d1
d8e8 d1e2 e8f8 e2e1 f8f7 a1b1 f7e7 c3c4 e7f7 f2f4 g5f4 c4c5 f4f3 g1f3 a7a6 e1e2
f7f8 b4b5 a6b5 b1b5
31 -95 14759 509767417  e1e2

And UCT

Code: Select all

Time : 1114797ms Tree : nodes 17666975 depth 52 pps 35881 visits 40001000
e3e4   0.06     653    11365
g2g3   0.07   18775   266533
g2g4   0.07   13903   198863
f2f3   0.07    9342   135235
f2f4   0.07    8736   126748
d2d3   0.07    8833   128100
d2d4   0.06    1352    21801
c2c3   0.07    4810    71463
c2c4   0.06    1143    18714
b2b3   0.07   10091   145704
b2b4   0.06    1991    31130
a2a3   0.07   13984   199997
a2a4   0.07   12209   175269
g1h3   0.11  3949585   36821973
g1e2   0.07    8857   128436
g1f3   0.07   66272   920468
a1b1   0.07   13297   190434
e1e2   0.07    8979   130152
e1f1   0.07    9139   132386
e1d1   0.07   10128   146229
Best move : g1h3

[Vladimir Xern]

About the position, White has a clear advantage. His plan is to advance his pawns and force Black to exchange pieces, after which Black will be so restricted that he'll run out of safe moves. At that point, either Black's rook or bishop will be unleashed and be forced to capture all of White's army.

I'm not sure if it's the absolute best move, but the game continued 1.f4 Nxf4 2.exf4 Kd8 3.d4 Ke8 4.d5 g5 5.fxg5 Kf8 6.a4 Ke8 7.Ra3 Kd8 8.Rh3 a6 9.b4 Kc7 10.c4 Kb6 11.a5 Kxa5 12.bxa5 Nh6 13.gxh6 and Black is lost.

Looking at a few of the alpha-beta's PVs, it seems to make a few useless moves and meanders a bit. Is that just noise from the hash table?

Also, looking over the game you posted, it's interesting that the UCT version can see a win for Black in this position when a pure PN searcher like Sjeng thinks the position is roughly level.

[D]1nb5/2p1P3/3pp3/p7/8/P3P3/2pP1P2/2B2B2 w - - 0 21

Despite that, the alpha-beta plays the instantly losing 21.e8=Q. What does Nebiyu think after something like 21.a4?