Michael Chaly
a8401e803d
Adjust bonus to move that caused a fail low
...
This is an elo gainer and simultaneously a minor logical fix to bonuses that caused a fail low.
It increases maximum of statscore based subtraction - but disallows negative bonuses.
Passed STC:
https://tests.stockfishchess.org/tests/view/66955e6f4ff211be9d4ec063
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 44640 W: 11805 L: 11472 D: 21363
Ptnml(0-2): 166, 5178, 11335, 5439, 202
Passed LTC:
https://tests.stockfishchess.org/tests/view/66963fde4ff211be9d4ec190
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 72288 W: 18478 L: 18082 D: 35728
Ptnml(0-2): 50, 7919, 19825, 8285, 65
closes https://github.com/official-stockfish/Stockfish/pull/5494
Bench: 1477054
2024-07-19 08:41:38 +02:00
Shahin M. Shahin
c8d8e362fc
Try nullmoves only on cutnodes
...
since master only tries nullmoves on cutNodes already with 99.0224% of the
cases running bench, We can try null moves at 100% of cutNodes and achieve such
simplification, by making passing false already equivalent to passing !cutNode
This is a more correct form of PR #5482
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/66941c044ff211be9d4ebf5f
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 153216 W: 39856 L: 39764 D: 73596
Ptnml(0-2): 590, 18174, 38979, 18284, 581
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/6694e5cd4ff211be9d4ebfdf
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67842 W: 17178 L: 17004 D: 33660
Ptnml(0-2): 52, 7437, 18759, 7631, 42
closes https://github.com/official-stockfish/Stockfish/pull/5490
bench: 1345400
Co-Authored-By: FauziAkram <11150271+fauziakram@users.noreply.github.com>
2024-07-19 08:38:13 +02:00
Dubslow
27042fe949
Linearize corrHist
...
Passed STC: https://tests.stockfishchess.org/tests/view/66919cdec6827afcdcee146f
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 130656 W: 33579 L: 33461 D: 63616
Ptnml(0-2): 394, 15548, 33318, 15682, 386
Passed VVLTC: https://tests.stockfishchess.org/tests/view/6691acb2c6827afcdcee1645
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 160314 W: 40925 L: 40854 D: 78535
Ptnml(0-2): 12, 14754, 50551, 14831, 9
closes https://github.com/official-stockfish/Stockfish/pull/5489
bench 1380295
2024-07-19 08:36:25 +02:00
yl25946
7bb45d05fa
Replace ternary with std::min
...
equivalent and more readable.
closes https://github.com/official-stockfish/Stockfish/pull/5488
No functional change
2024-07-19 08:34:02 +02:00
Guenther Demetz
c755bc1a73
Simplify improving condition
...
if we were in check at our previous move we look back until we weren't
in check and take the staticEval of that position as reference.
Passed STC:
https://tests.stockfishchess.org/tests/view/668ba7b65034141ae5996665
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 74784 W: 19454 L: 19274 D: 36056
Ptnml(0-2): 260, 8874, 18952, 9038, 268
Passted LTC:
https://tests.stockfishchess.org/tests/view/668cb2db5034141ae599678b
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 241488 W: 61166 L: 61171 D: 119151
Ptnml(0-2): 190, 27154, 66062, 27147, 191
closes https://github.com/official-stockfish/Stockfish/pull/5492
bench: 1368313
2024-07-19 08:32:16 +02:00
Michael Chaly
de2bf1a186
Remove quiet history pruning depth limit
...
This patch removes lmrDepth limit for quiet moves history based pruning.
Previously removal of this type of depth limits was considered bad because it
was performing bad for matetrack - but with this pruning heuristic this
shouldn't be that bad because it's "naturally" depth limited by history
threshold and should be completely disabled at depth >= 15 or so. Also this
heuristic in previous years was known to scale non-linearly - bigger lmrDepth
thresholds were better at longer time controls and removing it completely
probably should scale pretty well.
Passed STC:
https://tests.stockfishchess.org/tests/view/6692b89b4ff211be9d4eab21
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 114464 W: 29675 L: 29545 D: 55244
Ptnml(0-2): 372, 12516, 31329, 12640, 375
Passed LTC:
https://tests.stockfishchess.org/tests/view/6692c4554ff211be9d4eab3d
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 67746 W: 17182 L: 17014 D: 33550
Ptnml(0-2): 28, 6993, 19652, 7183, 17
closes https://github.com/official-stockfish/Stockfish/pull/5485
Bench: 1250388
2024-07-15 13:35:06 +02:00
MinetaS
2b37b151dd
Use ValueList to represent searched moves array
...
This PR replaces a pair of array and size with existing ValueList class.
Removes two local variables in search and two parameters of
update_all_stats.
Passed non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 227040 W: 58472 L: 58463 D: 110105
Ptnml(0-2): 495, 23572, 65427, 23481, 545
https://tests.stockfishchess.org/tests/view/669299204ff211be9d4e98dc
closes https://github.com/official-stockfish/Stockfish/pull/5484
No functional change
2024-07-15 13:30:47 +02:00
FauziAkram
7395d56832
bonus calculation for prior countermoves
...
Introduce a new term to the bonus calculation for prior countermoves
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 140896 W: 36545 L: 36079 D: 68272
Ptnml(0-2): 383, 16505, 36217, 16949, 394
https://tests.stockfishchess.org/tests/view/6691c73cc6827afcdcee1816
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 126660 W: 32089 L: 31587 D: 62984
Ptnml(0-2): 63, 13774, 35154, 14276, 63
https://tests.stockfishchess.org/tests/view/6691cdc4c6827afcdcee1930
closes https://github.com/official-stockfish/Stockfish/pull/5483
bench: 1250388
2024-07-15 13:27:42 +02:00
Linmiao Xu
558abdbe8a
Set best value to futility value after pruned quiet move
...
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/6691592f5034141ae599c68d
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 278496 W: 71818 L: 71865 D: 134813
Ptnml(0-2): 865, 33311, 70978, 33194, 900
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/66918fca5034141ae599e761
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 202986 W: 51048 L: 51013 D: 100925
Ptnml(0-2): 107, 22552, 56133, 22601, 100
closes https://github.com/official-stockfish/Stockfish/pull/5480
bench 1715206
2024-07-15 13:24:14 +02:00
Michael Chaly
930915de90
Decrease delta
...
Decrease delta in aspiration windows - both initial value and quadratic
function of previous best value.
Passed STC:
https://tests.stockfishchess.org/tests/view/6691a52ec6827afcdcee1569
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 55456 W: 14449 L: 14107 D: 26900
Ptnml(0-2): 174, 6416, 14193, 6784, 161
Passed LTC:
https://tests.stockfishchess.org/tests/view/6691aac1c6827afcdcee1625
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 107940 W: 27530 L: 27065 D: 53345
Ptnml(0-2): 52, 11787, 29840, 12226, 65
closes https://github.com/official-stockfish/Stockfish/pull/5479
bench 1547707
2024-07-15 13:22:31 +02:00
MinetaS
563d268519
Simplify futility_move_count
...
This patch reverts changes from #4032 which was introduced as a speedup.
Modern compilers no longer use DIV/IDIV instructions, potentially making
the explicit branch perform worse. Since evaluations spend significantly
more time now, the impact of the speedup in search diminishes with old
compilers as well.
GCC 14.1.0 profile-build, x86-64-vnni512
```
.text:000000014010FEA9 mov ecx, [rsp+3FB8h+var_3F5C]
...
.text:000000014010FEBD mov r10d, ecx
.text:000000014010FEC0 imul r10d, ecx
.text:000000014010FEC4 mov ecx, dword ptr [rsp+3FB8h+var_3F44+4]
.text:000000014010FEC8 add r10d, 3
.text:000000014010FECC mov r11d, r10d
.text:000000014010FECF sar r11d, 1
.text:000000014010FED2 cmp [rsp+3FB8h+var_3EE7], 0
.text:000000014010FEDA cmovnz r11d, r10d
```
LLVM 18.1.18 profile-build, x86-64-vnni512
```
.text:0000000140001EDC mov [rsp+40h+arg_E0], r13
.text:0000000140001EE4 movsxd rcx, r13d
.text:0000000140001EE7 mov rax, rcx
.text:0000000140001EEA mov [rsp+40h+arg_B8], rcx
.text:0000000140001EF2 imul eax, eax
.text:0000000140001EF5 add eax, 3
.text:0000000140001EF8 mov ecx, [rsp+40h+arg_8C]
.text:0000000140001EFF shrx eax, eax, ecx
.text:0000000140001F04 mov [rsp+40h+arg_190], rax
```
Passed non-regression STC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 109504 W: 28420 L: 28280 D: 52804
Ptnml(0-2): 355, 12326, 29273, 12420, 378
https://tests.stockfishchess.org/tests/view/6690dc095034141ae599c5fe
closes https://github.com/official-stockfish/Stockfish/pull/5478
No functional change
2024-07-15 13:19:46 +02:00
yl25946
8d1e41458e
removed second killer move
...
STC with movepicker rewrite:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 46656 W: 12208 L: 11995 D: 22453
Ptnml(0-2): 203, 5461, 11777, 5694, 193
https://tests.stockfishchess.org/tests/view/668d98a15034141ae5999e68
Earlier version passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 468896 W: 120999 L: 120054 D: 227843
Ptnml(0-2): 1207, 55209, 120639, 56218, 1175
https://tests.stockfishchess.org/tests/view/668b17d2cf91c430fca58630
Earlier version passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 550524 W: 139553 L: 139877 D: 271094
Ptnml(0-2): 333, 61646, 151616, 61346, 321
https://tests.stockfishchess.org/tests/view/668b2e04cf91c430fca586b1
closes https://github.com/official-stockfish/Stockfish/pull/5472
bench 1234309
Co-authored-by: rn5f107s2 <clemens.lerchl@gmail.com>
2024-07-11 07:29:49 +02:00
Stéphane Nicolet
7e72b37e4c
Clean up comments in code
...
- Capitalize comments
- Reformat multi-lines comments to equalize the widths of the lines
- Try to keep the width of comments around 85 characters
- Remove periods at the end of single-line comments
closes https://github.com/official-stockfish/Stockfish/pull/5469
No functional change
2024-07-11 07:29:33 +02:00
yl25946
362a77a345
Move Loop Consistency in Probcut
...
In probcut move loop, everything is enclosed within a large if statement. I've
changed it to guard clauses to stay consistent with other move loops.
closes https://github.com/official-stockfish/Stockfish/pull/5463
No functional change
2024-07-09 18:54:12 +02:00
Shawn Xu
4880ed4ad1
Simplify Probcut Malus
...
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 74880 W: 19261 L: 19083 D: 36536
Ptnml(0-2): 202, 8861, 19120, 9071, 186
https://tests.stockfishchess.org/tests/view/668a0966eca84f4d25864cba
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 263916 W: 66690 L: 66718 D: 130508
Ptnml(0-2): 125, 29348, 73040, 29320, 125
https://tests.stockfishchess.org/tests/view/668a17e3eca84f4d25864e91
closes https://github.com/official-stockfish/Stockfish/pull/5464
bench 1331408
2024-07-09 18:44:39 +02:00
Michael Chaly
eac2d080a3
Further simplify stat bonuses
...
Based on recent simplification by linrock Since it completely removed any
special bonuses based on values difference and made it flat stat_bonus(depth +
1) I got an idea that we might as well remove all (depth + 1) bonuses and make
them usual depth bonuses. Also removes weird negative bonus for depth 1 as a
side effect.
Passed STC:
https://tests.stockfishchess.org/tests/view/6689d817eca84f4d25863746
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 18080 W: 4789 L: 4552 D: 8739
Ptnml(0-2): 46, 1987, 4727, 2244, 36
Passed LTC:
https://tests.stockfishchess.org/tests/view/6689daa4eca84f4d258639d7
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 109062 W: 27548 L: 27417 D: 54097
Ptnml(0-2): 58, 11983, 30293, 12164, 33
Passed direct LTC vs linrock patch:
https://tests.stockfishchess.org/tests/view/668a46f8eca84f4d25866fe9
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 100002 W: 25351 L: 25209 D: 49442
Ptnml(0-2): 54, 11119, 27529, 11229, 70
closes https://github.com/official-stockfish/Stockfish/pull/5461
Bench 1175744
2024-07-09 18:41:36 +02:00
Joost VandeVondele
5d3517c601
Fix output for GUI
...
Fritz 19 can hang with the current way to provide output,
i.e. too much output in a short time for a mate / depth 245 found quickly.
fallout from 25361e514bhttps://github.com/official-stockfish/Stockfish/pull/5460
No functional change
2024-07-09 18:36:46 +02:00
Linmiao Xu
4e9fded5a6
Larger bonus when updating quiet stats
...
Also removes unused arguments to update_all_stats to
fix compiler warnings about unused parameters.
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/6689a79a0fdd852d63cf52e9
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 26496 W: 6901 L: 6669 D: 12926
Ptnml(0-2): 62, 3094, 6715, 3304, 73
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/6689a9960fdd852d63cf532d
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 41214 W: 10373 L: 10173 D: 20668
Ptnml(0-2): 11, 4491, 11412, 4673, 20
closes https://github.com/official-stockfish/Stockfish/pull/5456
bench 1169958
2024-07-09 18:31:02 +02:00
Michael Chaly
75c8cb2c2f
Adjust usage of previous statscore in bonus assignments
...
This patch adjusts usage of previous statscore for bonus assginments - allowing
it for any statscores and clamping it to wider range.
Passed STC:
https://tests.stockfishchess.org/tests/view/66892e76e59d990b103f6a91
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 431520 W: 111767 L: 110872 D: 208881
Ptnml(0-2): 1180, 51165, 110133, 52144, 1138
Passed LTC:
https://tests.stockfishchess.org/tests/view/66897176e59d990b103f9605
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 143184 W: 36463 L: 35929 D: 70792
Ptnml(0-2): 55, 15540, 39863, 16084, 50
closes https://github.com/official-stockfish/Stockfish/pull/5455
bench 1330556
2024-07-09 18:29:09 +02:00
Linmiao Xu
bb9b65408f
Simplify improving deduction in futility margin
...
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/668981d4df142e108ffc9bb4
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 312672 W: 80280 L: 80363 D: 152029
Ptnml(0-2): 729, 37198, 80529, 37187, 693
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/668988c6df142e108ffca042
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 126042 W: 31971 L: 31857 D: 62214
Ptnml(0-2): 50, 13988, 34832, 14100, 51
closes https://github.com/official-stockfish/Stockfish/pull/5454
bench 1100483
2024-07-09 18:28:06 +02:00
Shawn Xu
2d3ef434b4
Tweak LMR at Root
...
Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 328192 W: 84751 L: 84014 D: 159427
Ptnml(0-2): 758, 38802, 84253, 39511, 772
https://tests.stockfishchess.org/tests/view/6689203959cb3228a4759a49
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 56748 W: 14494 L: 14136 D: 28118
Ptnml(0-2): 19, 6089, 15803, 6441, 22
https://tests.stockfishchess.org/tests/view/66892d76e59d990b103f6626
closes https://github.com/official-stockfish/Stockfish/pull/5452
Bench 1253593
2024-07-09 18:26:35 +02:00
Shawn Xu
b79ac764ff
Simplify in-check condition for Probcut-in-check
...
dont let your memes be dreams !?
Passed Non-regression STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 512000 W: 132193 L: 132497 D: 247310
Ptnml(0-2): 1600, 61170, 130704, 60986, 1540
https://tests.stockfishchess.org/tests/view/66838911c4f539faa03268a2
Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 380268 W: 95894 L: 96042 D: 188332
Ptnml(0-2): 193, 42861, 104180, 42701, 199
https://tests.stockfishchess.org/tests/view/6688d0550c9d7c1ab33ed5a8
closes https://github.com/official-stockfish/Stockfish/pull/5443
Bench: 1130282
2024-07-09 18:24:40 +02:00
Shawn Xu
b1f522930d
Simplify Away Move Count Pruning Adjustment
...
Using Singular Search Result
Passed Non-regression STC:
LLR: 3.01 (-2.94,2.94) <-1.75,0.25>
Total: 62688 W: 16319 L: 16121 D: 30248
Ptnml(0-2): 196, 7317, 16104, 7547, 180
https://tests.stockfishchess.org/tests/view/66879bf51b527f04dd477ff9
Passed Non-regression LTC:
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 116502 W: 29504 L: 29379 D: 57619
Ptnml(0-2): 66, 12881, 32226, 13018, 60
https://tests.stockfishchess.org/tests/view/6688629e0c9d7c1ab33ed030
closes https://github.com/official-stockfish/Stockfish/pull/5442
bench 1207930
2024-07-09 18:20:26 +02:00
Muzhen Gaming
4d6e1225bd
Simplify ttPv reduction formula
...
This is a revert of 2046c92https://tests.stockfishchess.org/tests/view/6689266e59cb3228a4759b28
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 100320 W: 25913 L: 25763 D: 48644
Ptnml(0-2): 270, 11842, 25750, 12064, 234
Simplification LTC: https://tests.stockfishchess.org/tests/view/66893103e59d990b103f6ab3
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 57078 W: 14466 L: 14282 D: 28330
Ptnml(0-2): 34, 6214, 15851, 6414, 26
closes https://github.com/official-stockfish/Stockfish/pull/5448
Bench: 1124658
2024-07-06 18:00:09 +02:00
Muzhen Gaming
55cb235d47
Simplify internal iterative reductions
...
This is a revert of cc992e5https://tests.stockfishchess.org/tests/view/6689266659cb3228a4759b26
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 96992 W: 24977 L: 24824 D: 47191
Ptnml(0-2): 251, 11497, 24851, 11642, 255
Simplification LTC: https://tests.stockfishchess.org/tests/view/668930ffe59d990b103f6ab1
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 35808 W: 9185 L: 8980 D: 17643
Ptnml(0-2): 25, 3776, 10101, 3973, 29
closes https://github.com/official-stockfish/Stockfish/pull/5447
Bench: 1097766
2024-07-06 17:58:23 +02:00
Shawn Xu
24ab46c511
Non-functional Fixes & Updates
...
Fixes a missing default slot for dbg_extremes of, removes a extra newline, and
updates SE elo estimate from
https://tests.stockfishchess.org/tests/view/664ebd1e928b1fb18de4e4b7 while we
are at it.
closes https://github.com/official-stockfish/Stockfish/pull/5446
No functional change
2024-07-06 17:56:31 +02:00
FauziAkram
ec8288fe0d
Simplify away eval in TM
...
Passed STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 40160 W: 10523 L: 10309 D: 19328
Ptnml(0-2): 129, 4543, 10524, 4753, 131
https://tests.stockfishchess.org/tests/view/6685ab8b99271ae49479dbe9
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 195672 W: 49681 L: 49639 D: 96352
Ptnml(0-2): 112, 20976, 55597, 21060, 91
https://tests.stockfishchess.org/tests/view/6686f27a7092ade1206f7889
closes https://github.com/official-stockfish/Stockfish/pull/5445
No functional change
2024-07-06 17:54:22 +02:00
Shawn Xu
a45c2bc34a
Simplify Away Countermove Heuristic
...
Passed Non-regression STC:
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 977824 W: 252072 L: 252888 D: 472864
Ptnml(0-2): 2518, 117120, 250560, 116088, 2626
https://tests.stockfishchess.org/tests/view/6683452d95b0d1e881e81541
Passed Non-regression LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 81048 W: 20630 L: 20470 D: 39948
Ptnml(0-2): 36, 8915, 22464, 9071, 38
https://tests.stockfishchess.org/tests/view/66886b7b0c9d7c1ab33ed281
closes https://github.com/official-stockfish/Stockfish/pull/5441
bench 1276784
2024-07-06 17:48:11 +02:00
Muzhen Gaming
daa9e217ab
VVLTC search tune
...
Passed VVLTC 1st sprt: https://tests.stockfishchess.org/tests/view/6688af640c9d7c1ab33ed327
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 16050 W: 4200 L: 3959 D: 7891
Ptnml(0-2): 0, 1383, 5018, 1624, 0
Passed VVLTC 2nd sprt: https://tests.stockfishchess.org/tests/view/6688e8900c9d7c1ab33efd60
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 44044 W: 11303 L: 10999 D: 21742
Ptnml(0-2): 1, 3973, 13772, 4273, 3
closes https://github.com/official-stockfish/Stockfish/pull/5444
Bench: 992058
2024-07-06 17:45:58 +02:00
Joost VandeVondele
2cbc20e846
Correct and extend PV lines with decisive TB score
...
Currently (after #5407 ), SF has the property that any PV line with a decisive
TB score contains the corresponding TB position, with a score that correctly
identifies the depth at which TB are entered. The PV line that follows might
not preserve the game outcome, but can easily be verified and extended based on
TB information. This patch provides this functionality, simply extending the PV
lines on output, this doesn't affect search.
Indeed, if DTZ tables are available, search based PV lines that correspond to
decisive TB scores are verified to preserve game outcome, truncating the line
as needed. Subsequently, such PV lines are extended with a game outcome
preserving line until mate, as a possible continuation. These lines are not
optimal mating lines, but are similar to what a user could produce on a website
like https://syzygy-tables.info/ clicking always the top ranked move, i.e.
minimizing or maximizing DTZ (with a simple tie-breaker for moves that have
identical DTZ), and are thus an just an illustration of how to game can be won.
A similar approach is already in established in
https://github.com/joergoster/Stockfish/tree/matefish2
This also contributes to addressing #5175 where SF can give an incorrect TB
win/loss for positions in TB with a movecounter that doesn't reflect optimal
play. While the full solution requires either TB generated differently, or a
search when ranking rootmoves, current SF will eventually find a draw in these
cases, in practice quite quickly, e.g.
`1kq5/q2r4/5K2/8/8/8/8/7Q w - - 96 1`
`8/8/6k1/3B4/3K4/4N3/8/8 w - - 54 106`
Gives the same results as master on an extended set of test positions from
9173d29c41https://github.com/vondele/matetrack using 6men TB, all generated PVs verify:
```
Using ../Stockfish/src/stockfish.syzygyExtend on matetrack.epd with --nodes 1000000 --syzygyPath /chess/syzygy/3-4-5-6/WDL:/chess/syzygy/3-4-5-6/DTZ
Engine ID: Stockfish dev-20240704-ff227954
Total FENs: 6555
Found mates: 3299
Best mates: 2582
Found TB wins: 568
```
As repeated DTZ probing could be slow a procedure (100ms+ on HDD, a few ms on
SSD), the extension is only done as long as the time taken is less than half
the `Move Overhead` parameter. For tournaments where these lines might be of
interest to the user, a suitable `Move Overhead` might be needed (e.g. TCEC has
1000ms already).
closes https://github.com/official-stockfish/Stockfish/pull/5414
No functional change
2024-07-05 15:43:49 +02:00
Linmiao Xu
3c379e55d9
Update 7 stat bonus/malus params
...
Values found around 119k / 120k spsa games at 60+0.6:
https://tests.stockfishchess.org/tests/view/6683112a192114e61f92f87a
Passed STC:
https://tests.stockfishchess.org/tests/view/66838148c4f539faa0326897
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 40928 W: 10835 L: 10508 D: 19585
Ptnml(0-2): 139, 4802, 10254, 5131, 138
Passed LTC:
https://tests.stockfishchess.org/tests/view/668448a87a1863935cee42c6
LLR: 2.96 (-2.94,2.94) <0.50,2.50>
Total: 29208 W: 7559 L: 7253 D: 14396
Ptnml(0-2): 17, 3118, 8019, 3442, 8
closes https://github.com/official-stockfish/Stockfish/pull/5439
bench 1138753
2024-07-05 15:43:49 +02:00
Joost VandeVondele
25361e514b
Output from a fix depth onward, instead of 3s.
...
To avoid output that depends on timing, output currmove and similar only from depth > 30
onward. Current choice of 3s makes the output of the same search depending on
the system load, and doesn't always start at move 1. Depth 30 is nowadays
reached in a few seconds on most systems.
closes https://github.com/official-stockfish/Stockfish/pull/5436
No functional change
2024-07-05 15:43:42 +02:00
Shahin M. Shahin
6b7822119f
Limit has_game_cycle() to only upcoming repetition
...
use the original algorithm according to the paper
http://web.archive.org/web/20201107002606/https://marcelk.net/2013-04-06/paper/upcoming-rep-v2.pdf ,
which detects accurately if a position has an upcoming repetition. The 'no
progress' part of has_game_cycle has been removed, the function has been
renamed to upcoming_repetition to reflect this.
As a result of this fix, to the best of our knowledge, all PVs for completed
iterations that yield a mate or decisive table base score now end in mate or
contain a TB position, respectively.
passed non-regression STC:
https://tests.stockfishchess.org/tests/view/6679fa1d0c2db3fa2dcecbf2
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 63584 W: 16666 L: 16472 D: 30446
Ptnml(0-2): 186, 7552, 16146, 7698, 210
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/667ac965e439ed1c7a9ca042
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 464574 W: 117493 L: 117729 D: 229352
Ptnml(0-2): 311, 52468, 126974, 52214, 320
closes https://github.com/official-stockfish/Stockfish/pull/5432
bench: 1209805
2024-07-03 13:35:49 +02:00
Shawn Xu
69ad4667fb
Do Capture History Updates In Probcut
...
This patch introduces history updates to probcut. Standard depth - 3 bonus and
maluses are given to the capture that caused fail high and previously searched
captures, respectively. Similar to #5243 , a negative history fill is applied to
compensate for an increase in capture history average, thus improving the
scaling of this patch.
Passed STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 84832 W: 21941 L: 21556 D: 41335
Ptnml(0-2): 226, 9927, 21688, 10386, 189
https://tests.stockfishchess.org/tests/view/6682fab9389b9ee542b1d029
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 104298 W: 26469 L: 26011 D: 51818
Ptnml(0-2): 43, 11458, 28677, 11940, 31
https://tests.stockfishchess.org/tests/view/6682ff06389b9ee542b1d0a0
closes https://github.com/official-stockfish/Stockfish/pull/5428
bench 1281351
2024-07-03 13:18:00 +02:00
Dubslow
6138a0fd0e
Probcut in check no matter if pv or capture
...
Passed STC: https://tests.stockfishchess.org/tests/view/6681e9c8c1657e386d294cef
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 217824 W: 56149 L: 56129 D: 105546
Ptnml(0-2): 587, 25926, 55848, 25982, 569
Passed LTC: https://tests.stockfishchess.org/tests/view/6681fcb8c1657e386d294db1
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 357552 W: 90546 L: 90671 D: 176335
Ptnml(0-2): 207, 40064, 98362, 39933, 210
Each half of this also passed STC+LTC separately
closes https://github.com/official-stockfish/Stockfish/pull/5427
bench 1227870
2024-07-01 20:07:03 +02:00
Linmiao Xu
843b6f7c98
Update some params for pruning at shallow depth
...
Values found around 82k / 120k spsa games at 60+0.6:
https://tests.stockfishchess.org/tests/view/6681aca4481148df247298bd
Passed STC:
https://tests.stockfishchess.org/tests/view/6681c795c1657e386d2948fa
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 145216 W: 37595 L: 37122 D: 70499
Ptnml(0-2): 375, 17122, 37185, 17507, 419
Passed LTC:
https://tests.stockfishchess.org/tests/view/6681d4eec1657e386d2949e0
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 154062 W: 39117 L: 38557 D: 76388
Ptnml(0-2): 67, 16874, 42608, 17396, 86
closes https://github.com/official-stockfish/Stockfish/pull/5425
bench 996419
2024-07-01 20:04:13 +02:00
Linmiao Xu
f6842a145c
Simplify worsening deduction in futility margin
...
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/66817d46442423e547141226
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 345408 W: 89146 L: 89266 D: 166996
Ptnml(0-2): 954, 41317, 88286, 41189, 958
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/66818dbe1e90a146232d1f62
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 173214 W: 43821 L: 43755 D: 85638
Ptnml(0-2): 108, 19407, 47492, 19511, 89
closes https://github.com/official-stockfish/Stockfish/pull/5424
bench 981017
2024-07-01 20:02:38 +02:00
FauziAkram
5deb262393
Simplify rm.averageScore calculation
...
Passed STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 485056 W: 125222 L: 125497 D: 234337
Ptnml(0-2): 1384, 58197, 123614, 57976, 1357
https://tests.stockfishchess.org/tests/view/6681816d442423e54714133f
Passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 56622 W: 14301 L: 14115 D: 28206
Ptnml(0-2): 31, 6259, 15538, 6459, 24
https://tests.stockfishchess.org/tests/view/6681a9a5596d543edc677490
closes https://github.com/official-stockfish/Stockfish/pull/5423
bench: 1171203
2024-07-01 20:01:05 +02:00
Shahin M. Shahin
38c5fc33e4
Increase reduction based on correct expectation
...
If the current node is not a cutNode then it means that the child is one in LMR
and the cutoff count is expected, so more reduction when the cutoffs are
expected
Passed STC:
https://tests.stockfishchess.org/tests/view/66815e791c5b344a34ca7090
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 64416 W: 16876 L: 16519 D: 31021
Ptnml(0-2): 150, 7670, 16264, 7921, 203
Passed LTC:
https://tests.stockfishchess.org/tests/view/668162f61c5b344a34ca725c
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 78186 W: 19905 L: 19499 D: 38782
Ptnml(0-2): 55, 8561, 21437, 9003, 37
closes https://github.com/official-stockfish/Stockfish/pull/5422
bench: 1161531
2024-07-01 19:58:13 +02:00
Michael Chaly
7b49f9dd70
Tweak multicut
...
This patch is an original patch by author of Altair
(https://github.com/Alex2262/AltairChessEngine ) chess engine.
It allows to produce more aggressive multicut compared to master by changing
condition it needs to fulfil and also returns bigger value. Also has applied
matetrack fix on top.
Passed STC:
https://tests.stockfishchess.org/tests/view/667223ab602682471b0650e2
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 50048 W: 13200 L: 12860 D: 23988
Ptnml(0-2): 181, 5822, 12679, 6160, 182
Passed LTC:
https://tests.stockfishchess.org/tests/view/6672f777602682471b06515d
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 706380 W: 179707 L: 177981 D: 348692
Ptnml(0-2): 656, 79250, 191665, 80950, 669
closes https://github.com/official-stockfish/Stockfish/pull/5421
bench 1148966
2024-07-01 19:56:38 +02:00
Daniel Monroe
91ec31dac4
Grade countermove bonus for low statscores
...
Passed STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 338592 W: 88396 L: 87627 D: 162569
Ptnml(0-2): 1161, 40201, 85788, 41000, 1146
https://tests.stockfishchess.org/tests/view/6679d40c0c2db3fa2dcecbcc
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 83526 W: 21429 L: 21010 D: 41087
Ptnml(0-2): 54, 9173, 22913, 9546, 77
https://tests.stockfishchess.org/tests/view/667c5f2980450dba965911fc
closes https://github.com/official-stockfish/Stockfish/pull/5418
bench: 1489815
2024-07-01 19:53:45 +02:00
Taras Vuk
22a502ac74
Skip futility pruning if beta is below TB loss value
...
Passed STC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 77024 W: 20122 L: 19946 D: 36956
Ptnml(0-2): 278, 8754, 20277, 8920, 283
https://tests.stockfishchess.org/tests/view/66752d59602682471b0652f3
Passed LTC:
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 93114 W: 23623 L: 23477 D: 46014
Ptnml(0-2): 77, 9839, 26566, 10011, 64
https://tests.stockfishchess.org/tests/view/6676b3e1602682471b065395
closes https://github.com/official-stockfish/Stockfish/pull/5413
bench: 1003441
2024-07-01 19:48:06 +02:00
FauziAkram
cc992e5e4a
Internal iterative reductions: decrease depth more
...
For PV nodes without a ttMove, we decrease depth.
But in this patch, additionally, if the current position is found in the TT, and the stored depth in the TT is greater than or equal to
the current search depth, we decrease the search depth even further.
Passed STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 84384 W: 22154 L: 21761 D: 40469
Ptnml(0-2): 292, 9972, 21315, 10277, 336
https://tests.stockfishchess.org/tests/view/666b0a4d602682471b064db6
Passed LTC:
LLR: 2.95 (-2.94,2.94) <0.50,2.50>
Total: 92106 W: 23471 L: 23032 D: 45603
Ptnml(0-2): 79, 10155, 25154, 10578, 87
https://tests.stockfishchess.org/tests/view/666c423d602682471b064e56
closes https://github.com/official-stockfish/Stockfish/pull/5397
bench: 1038234
2024-06-23 11:46:41 +02:00
Shawn Xu
d5c130569b
Simplify Bonus Formula In History Adjustment
...
Inspired by a discord message [1] from Vizvezdenec, this patch simplifies the
bonus adjustment bonus = bonus > 0 ? 2 * bonus : bonus / 2 to a constant
addition, maintaining bonus average at around 0 in regular bench. As cj5716
pointed in discord [2], the constant bonus can also be considered as factoring
tempo when calculating bonus, yielding a better value of the move.
[1] https://discord.com/channels/435943710472011776/882956631514689597/1243877089443188776
[2] https://discord.com/channels/435943710472011776/813919248455827515/1252277437249622077
Passed Non-regression STC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 29984 W: 7908 L: 7677 D: 14399
Ptnml(0-2): 95, 3502, 7594, 3679, 122
https://tests.stockfishchess.org/tests/view/666f7210602682471b064fa2
Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 170136 W: 43214 L: 43145 D: 83777
Ptnml(0-2): 158, 19185, 46311, 19258, 156
https://tests.stockfishchess.org/tests/view/666fb32e602682471b064fb5
closes https://github.com/official-stockfish/Stockfish/pull/5401
bench 1438375
2024-06-23 11:41:48 +02:00
evqsx
8806a58ebf
Simplify static exchange evaluation pruning formula
...
Passed STC: https://tests.stockfishchess.org/tests/view/666bda31602682471b064e1f
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 141696 W: 36932 L: 36826 D: 67938
Ptnml(0-2): 510, 16880, 35989, 16932, 537
Passed LTC: https://tests.stockfishchess.org/tests/view/666e6b67602682471b064f4b
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 159504 W: 40552 L: 40471 D: 78481
Ptnml(0-2): 130, 18160, 43103, 18217, 142
closes https://github.com/official-stockfish/Stockfish/pull/5400
bench: 1084115
2024-06-23 11:37:32 +02:00
xoto10
2678606e8d
Consider wider range of moves near leaves.
...
try to avoid missing good moves for opponent or engine, by updating bestMove
also when value == bestValue (i.e. value == alpha) under certain conditions.
In particular require this is at higher depth in the tree, leaving the logic
near the root unchanged, and only apply randomly. Avoid doing this near mate
scores, leaving mate PVs intact.
Passed SMP STC 6+0.06 th7 :
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 42040 W: 10930 L: 10624 D: 20486
Ptnml(0-2): 28, 4682, 11289, 4998, 23
https://tests.stockfishchess.org/tests/view/66608b00c340c8eed7757d1d
Passed SMP LTC 24+0.24 th7 :
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 73692 W: 18978 L: 18600 D: 36114
Ptnml(0-2): 9, 7421, 21614, 7787, 15
https://tests.stockfishchess.org/tests/view/666095e8c340c8eed7757d49
closes https://github.com/official-stockfish/Stockfish/pull/5367
Bench 1205168
2024-06-23 11:29:02 +02:00
FauziAkram
2046c92ad4
Tweak the reduction formula
...
Tweak the reduction formula if position is or has been on the PV
Taking inspiration from an old Viren test.
Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 78528 W: 20607 L: 20225 D: 37696
Ptnml(0-2): 262, 9297, 19785, 9637, 283
https://tests.stockfishchess.org/tests/view/666339c70ff7cb4868d1fe24
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 138630 W: 35666 L: 35132 D: 67832
Ptnml(0-2): 118, 15345, 37835, 15919, 98
https://tests.stockfishchess.org/tests/view/66645dec0612cd151f9e77b0
closes https://github.com/official-stockfish/Stockfish/pull/5385
Bench: 1134281
2024-06-15 12:13:59 +02:00
Joost VandeVondele
b01fdb596a
Fix upperbound/lowerbound output in multithreaded case
...
In case a stop is received during multithreaded searches, the PV of the best
thread might be printed without the correct upperbound/lowerbound indicators.
This was due to the pvIdx variable being incremented after receiving the stop.
passed STC:
https://tests.stockfishchess.org/tests/view/666985da602682471b064d08
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 196576 W: 51039 L: 50996 D: 94541
Ptnml(0-2): 760, 22545, 51603, 22652, 728
closes https://github.com/official-stockfish/Stockfish/pull/5391
Bench: 1160467
2024-06-15 12:08:29 +02:00
Joost VandeVondele
3d92950859
Limit depth after extensions to avoid asserts.
...
currently extensions can cause depth to exceed MAX_PLY.
This triggers the assert near line 542 in search when running a binary compiled with `debug=yes` on a testcase like:
```
position fen 7K/P1p1p1p1/2P1P1Pk/6pP/3p2P1/1P6/3P4/8 w - - 0 1
go nodes 1000000
```
passed STC
https://tests.stockfishchess.org/tests/view/6668a56a602682471b064c8d
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 143936 W: 37338 L: 37238 D: 69360
Ptnml(0-2): 514, 16335, 38149, 16477, 493
closes https://github.com/official-stockfish/Stockfish/pull/5383
Bench: 1160467
2024-06-15 12:02:56 +02:00
Dubslow
c8213ba0d0
Simplify TT interface and avoid changing TT info
...
This commit builds on the work and ideas of #5345 , #5348 , and #5364 .
Place as much as possible of the TT implementation in tt.cpp, rather than in the
header. Some commentary is added to better document the public interface.
Fix the search read-TT races, or at least contain them to within TT methods only.
Passed SMP STC: https://tests.stockfishchess.org/tests/view/666134ab91e372763104b443
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 512552 W: 132387 L: 132676 D: 247489
Ptnml(0-2): 469, 58429, 138771, 58136, 471
The unmerged version has bench identical to the other PR (see also #5348 ) and
therefore those same-functionality tests:
SMP LTC: https://tests.stockfishchess.org/tests/view/665c7021fd45fb0f907c214a
SMP LTC: https://tests.stockfishchess.org/tests/view/665d28a7fd45fb0f907c5495
closes https://github.com/official-stockfish/Stockfish/pull/5369
bench 1205675
2024-06-12 09:17:04 +02:00
