lonfom169
b8f4903fbb
Reintroduce singularQuietLMR
...
STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 88912 W: 23972 L: 23580 D: 41360
Ptnml(0-2): 365, 9820, 23712, 10176, 383
https://tests.stockfishchess.org/tests/view/62e9537a400addce2c13399b
LTC:
LLR: 2.97 (-2.94,2.94) <0.50,2.50>
Total: 85672 W: 23607 L: 23192 D: 38873
Ptnml(0-2): 219, 8316, 25365, 8703, 233
https://tests.stockfishchess.org/tests/view/62e9a174400addce2c1346e4
closes https://github.com/official-stockfish/Stockfish/pull/4122
Bench: 5921315
2022-08-06 13:52:36 +02:00
Stefan Geschwentner
675f6a038b
Tweak history updates
...
In general the history update bonus is slightly decreased by 11% which gives a slower saturation speed.
In addition only for main history the divisor is halfed (used history values are doubled to maintain same maximum)
which have an effect in the opposite direction on saturation speed.
STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 157088 W: 42673 L: 42168 D: 72247
Ptnml(0-2): 857, 17346, 41642, 17833, 866
https://tests.stockfishchess.org/tests/view/62e5517ab383a712b13867c5
LTC:
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 325592 W: 88705 L: 87753 D: 149134
Ptnml(0-2): 594, 32288, 96076, 33248, 590
https://tests.stockfishchess.org/tests/view/62e5e4f4b383a712b1387d53
closes https://github.com/official-stockfish/Stockfish/pull/4119
Bench: 5518728
2022-08-06 13:50:01 +02:00
Michael Chaly
582c88ee94
Do more TT cutoffs in case of exact bound
...
The idea is that these TT entries are considered move valuable in TT replacement scheme - they are always overwriting other entries. So it makes sence for them to produce more aggressive cutoffs.
passed STC
https://tests.stockfishchess.org/tests/view/62e4d407b383a712b1385410
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 96632 W: 26045 L: 25659 D: 44928
Ptnml(0-2): 434, 10635, 25770, 11065, 412
passed LTC
https://tests.stockfishchess.org/tests/view/62e523e2b383a712b1386193
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 77960 W: 21363 L: 20989 D: 35608
Ptnml(0-2): 190, 7591, 23009, 8035, 155
closes https://github.com/official-stockfish/Stockfish/pull/4114
bench 5820568
2022-07-31 11:03:28 +02:00
Dubslow
c4a644922d
Simplify reduction condition for cutNodes
...
LMR: for cutNodes, dont exclude killer moves. This was a prelude to reducing
allNodes, altho that's failed so far.
STC https://tests.stockfishchess.org/tests/view/62d64ad147ae1768b34a27c3
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 37064 W: 10044 L: 9889 D: 17131
Ptnml(0-2): 162, 4115, 9828, 4260, 167
LTC https://tests.stockfishchess.org/tests/view/62d66cc047ae1768b34a2b14
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 39832 W: 10796 L: 10659 D: 18377
Ptnml(0-2): 69, 3969, 11706, 4100, 72
closes https://github.com/official-stockfish/Stockfish/pull/4109
bench: 5697891
2022-07-24 09:18:38 +02:00
Michael Chaly
95d24b77df
Simplify away some unneeded code in time management
...
The lower bound of the clamp is never used since complexity can't be negative and thus is unneeded.
closes https://github.com/official-stockfish/Stockfish/pull/4105
No functional change
2022-07-13 18:00:39 +02:00
Joost VandeVondele
2e02dd7936
Limit the researching at same depth.
...
If the elapsed time is close to the available time, the time management thread can signal that the next iterations should be searched at the same depth (Threads.increaseDepth = false). While the rootDepth increases, the adjustedDepth is kept constant with the searchAgainCounter.
In exceptional cases, when threading is used and the master thread, which controls the time management, signals to not increaseDepth, but by itself takes a long time to finish the iteration, the helper threads can search repeatedly at the same depth. This search finishes more and more quickly, leading to helper threads that report a rootDepth of MAX_DEPTH (245). The latter is not optimal as it is confusing for the user, stops search on these threads, and leads to an incorrect bias in the thread voting scheme. Probably with only a small impact on strength.
This behavior was observed almost two years ago,
see https://github.com/official-stockfish/Stockfish/issues/2717
This patch fixes #2717 by ensuring the effective depth increases at once every four iterations,
even in increaseDepth is false.
Depth 245 searches (for non-trivial positions) were indeed absent with this patch,
but frequent with master in the tests below:
https://discord.com/channels/435943710472011776/813919248455827515/994872720800088095
Total pgns: 2173
Base: 2867
Patch: 0
it passed non-regression testing in various setups:
SMP STC:
https://tests.stockfishchess.org/tests/view/62bfecc96178ffe6394ba036
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 37288 W: 10171 L: 10029 D: 17088
Ptnml(0-2): 75, 3777, 10793, 3929, 70
SMP LTC:
https://tests.stockfishchess.org/tests/view/62c08f6f49b62510394be066
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 190568 W: 52125 L: 52186 D: 86257
Ptnml(0-2): 70, 17854, 59504, 17779, 77
LTC:
https://tests.stockfishchess.org/tests/view/62c08b6049b62510394bdfb6
LLR: 2.96 (-2.94,2.94) <-2.25,0.25>
Total: 48120 W: 13204 L: 13083 D: 21833
Ptnml(0-2): 54, 4458, 14919, 4571, 58
Special thanks to miguel-I, Disservin, ruicoelhopedro and others for analysing the problem,
the data, and coming up with the key insight, needed to fix this longstanding issue.
closes https://github.com/official-stockfish/Stockfish/pull/4104
Bench: 5182295
2022-07-09 10:58:04 +02:00
Dubslow
aa18b68033
Time mgmt fix division.
...
oversight changed the corresponding float division to integer division in a previous tune 442c40b43dhttps://tests.stockfishchess.org/tests/view/62bf34bc0340fb1e0cc934e7
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 38952 W: 10738 L: 10467 D: 17747
Ptnml(0-2): 46, 3576, 11968, 3833, 53
yellow STC: https://tests.stockfishchess.org/tests/view/62bff6506178ffe6394ba1d1
LLR: -2.95 (-2.94,2.94) <0.00,2.50>
Total: 226960 W: 61265 L: 61062 D: 104633
Ptnml(0-2): 938, 24398, 62582, 24647, 915
further slightly tweaked tests confirm this Elo gain.
closes https://github.com/official-stockfish/Stockfish/pull/4097
No functional change
2022-07-09 10:53:17 +02:00
Dubslow
442c40b43d
Use NNUE complexity in search, retune related parameters
...
This builds on ideas of xoto10 and mstembera to use more output from NNUE in the search algorithm.
passed STC:
https://tests.stockfishchess.org/tests/view/62ae454fe7ee5525ef88a957
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 89208 W: 24127 L: 23753 D: 41328
Ptnml(0-2): 400, 9886, 23642, 10292, 384
passed LTC:
https://tests.stockfishchess.org/tests/view/62acc6ddd89eb6cf1e0750a1
LLR: 2.93 (-2.94,2.94) <0.50,3.00>
Total: 56352 W: 15430 L: 15115 D: 25807
Ptnml(0-2): 44, 5501, 16782, 5794, 55
closes https://github.com/official-stockfish/Stockfish/pull/4088
bench 5332964
2022-06-20 08:30:57 +02:00
Dubslow
5304b561ab
LMR: remove deeper
...
...apparently it wasn't doing much anymore. inspired by rufish's recent attempts to improve this.
passed STC:
https://tests.stockfishchess.org/tests/view/62abca2cd89eb6cf1e072c04
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 85576 W: 22766 L: 22683 D: 40127
Ptnml(0-2): 362, 9607, 22741, 9742, 336
passed LTC:
https://tests.stockfishchess.org/tests/view/62ac90ffd89eb6cf1e07488f
LLR: 2.93 (-2.94,2.94) <-2.25,0.25>
Total: 48248 W: 13018 L: 12896 D: 22334
Ptnml(0-2): 32, 4773, 14400, 4879, 40
closes https://github.com/official-stockfish/Stockfish/pull/4088
bench 5578988
2022-06-20 08:25:50 +02:00
bmc4
4d6a11a04c
Don't change ttPv at probCut
...
STC:
LLR: 2.96 (-2.94,2.94) <-2.25,0.25>
Total: 35672 W: 9618 L: 9462 D: 16592
Ptnml(0-2): 151, 3890, 9601, 4040, 154
https://tests.stockfishchess.org/tests/view/62ab03f750949cfc241b1965
LTC:
LLR: 2.93 (-2.94,2.94) <-2.25,0.25>
Total: 54160 W: 14626 L: 14511 D: 25023
Ptnml(0-2): 42, 5414, 16056, 5523, 45
https://tests.stockfishchess.org/tests/view/62ab5e6fd89eb6cf1e071b87
closes https://github.com/official-stockfish/Stockfish/pull/4088
bench: 5798229
2022-06-20 08:24:07 +02:00
bmc4
6edc29d720
Simplify away condition in ttSave in probCut
...
Remove condition for tte->save in probCut so it always saves on probCut cutoff.
STC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 47848 W: 12921 L: 12782 D: 22145
Ptnml(0-2): 207, 5340, 12715, 5431, 231
https://tests.stockfishchess.org/tests/view/62a1f7c87bd8e641e44436f7
LTC:
LLR: 2.97 (-2.94,2.94) <-2.25,0.25>
Total: 132736 W: 35895 L: 35881 D: 60960
Ptnml(0-2): 109, 13384, 39360, 13414, 101
https://tests.stockfishchess.org/tests/view/62a2421a7bd8e641e444434f
closes https://github.com/official-stockfish/Stockfish/pull/4069
bench: 5845802
2022-06-16 07:12:01 +02:00
mstembera
2d5dcf3d18
Minor simplifications and cleanup in search
...
STC: https://tests.stockfishchess.org/tests/view/629d6775593a4a9b6482c1ec
LLR: 2.93 (-2.94,2.94) <-2.25,0.25>
Total: 77416 W: 20683 L: 20589 D: 36144
Ptnml(0-2): 317, 8690, 20620, 8744, 337
LTC: https://tests.stockfishchess.org/tests/view/629db4be593a4a9b6482ceef
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 106544 W: 28752 L: 28705 D: 49087
Ptnml(0-2): 97, 10692, 31641, 10751, 91
closes https://github.com/official-stockfish/Stockfish/pull/4059
Bench: 5913510
2022-06-16 07:06:43 +02:00
candirufish
00297cfef0
Use qsearch on step 11 if depth is equal to or below 0
...
larger reduction of depth if no TT entry is found, and go in qsearch as needed.
stc:
https://tests.stockfishchess.org/tests/view/629dfacd593a4a9b6482db72
LLR: 2.93 (-2.94,2.94) <0.00,2.50>
Total: 31920 W: 8591 L: 8322 D: 15007
Ptnml(0-2): 127, 3551, 8376, 3738, 168
ltc:
https://tests.stockfishchess.org/tests/view/629e304e593a4a9b6482e451
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 17488 W: 4842 L: 4614 D: 8032
Ptnml(0-2): 13, 1670, 5151, 1896, 14
closes https://github.com/official-stockfish/Stockfish/pull/4056
Bench: 5870283
2022-06-07 08:34:14 +02:00
Dubslow
90cf8e7d2b
Remove LMR condition for complex pos
...
Inspired by Kia's similar test: https://tests.stockfishchess.org/tests/view/6292898c1e7cd5f29966fbe0
Passed STC:
https://tests.stockfishchess.org/tests/view/62941588b0d5a7d1b780ed4b
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 266872 W: 70850 L: 71033 D: 124989
Ptnml(0-2): 1180, 30114, 70941, 30111, 1090
Passed LTC:
https://tests.stockfishchess.org/tests/view/62964a754628d33daa24f062
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 70160 W: 18756 L: 18662 D: 32742
Ptnml(0-2): 42, 6976, 20950, 7070, 42
closes https://github.com/official-stockfish/Stockfish/pull/4047
Bench 6237567
2022-06-02 07:49:31 +02:00
candirufish
653bd0817c
cutnode and movecount lmr extension simplification
...
Passed STC
https://tests.stockfishchess.org/tests/view/6294133cb0d5a7d1b780ece3
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 41072 W: 11052 L: 10908 D: 19112
Ptnml(0-2): 153, 4324, 11461, 4422, 176
Passed LTC
ltc: https://tests.stockfishchess.org/tests/view/62947ae6b0d5a7d1b780fe86
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 102736 W: 27509 L: 27459 D: 47768
Ptnml(0-2): 98, 9734, 31669, 9754, 113
closes https://github.com/official-stockfish/Stockfish/pull/4045
Bench: 6410652
2022-06-02 07:44:22 +02:00
Michael Chaly
8fadbcf1b2
Add info about elo gained from some heuristics
...
Add info about qsearch and impact of main and continuation histories.
Based on these tests:
https://tests.stockfishchess.org/tests/view/62946ffcb0d5a7d1b780fc7e
https://tests.stockfishchess.org/tests/view/628facb71e7cd5f299669534
https://tests.stockfishchess.org/tests/view/628eade11e7cd5f299666f2e
closes https://github.com/official-stockfish/Stockfish/pull/4041
No functional change.
2022-06-02 07:43:14 +02:00
Giacomo Lorenzetti
1a168201bd
Small speedup in futility_move_count
...
The speedup is around 0.25% using gcc 11.3.1 (bmi2, nnue bench, depth 16
and 23) while it is neutral using clang (same conditions).
According to `perf` that integer division was one of the most time-consuming
instructions in search (gcc disassembly).
Passed STC:
https://tests.stockfishchess.org/tests/view/628a17fe24a074e5cd59b3aa
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 22232 W: 5992 L: 5751 D: 10489
Ptnml(0-2): 88, 2235, 6218, 2498, 77
yellow LTC:
https://tests.stockfishchess.org/tests/view/628a35d7ccae0450e35106f7
LLR: -2.95 (-2.94,2.94) <0.50,3.00>
Total: 320168 W: 85853 L: 85326 D: 148989
Ptnml(0-2): 185, 29698, 99821, 30165, 215
This patch also suggests that UHO STC is sensible to small speedups (< 0.50%).
closes https://github.com/official-stockfish/Stockfish/pull/4032
No functional change
2022-05-29 18:54:19 +02:00
Giacomo Lorenzetti
f7d1491b3d
Assorted small cleanups
...
closes https://github.com/official-stockfish/Stockfish/pull/3973
No functional change
2022-05-29 18:42:48 +02:00
candirufish
cc7bcd5303
Simplify a condition
...
Principal variation depth late move reduction extension simplification.
stc:
https://tests.stockfishchess.org/tests/view/6285a1d19d18a78568e7fa24
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 428536 W: 113433 L: 113851 D: 201252
Ptnml(0-2): 1671, 48606, 114090, 48272, 1629
ltc:
https://tests.stockfishchess.org/tests/view/62871d20375cdc5de8cf5db3
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 56792 W: 15123 L: 15011 D: 26658
Ptnml(0-2): 42, 5681, 16825, 5819, 29
closes https://github.com/official-stockfish/Stockfish/pull/4028
bench: 6501437
2022-05-21 12:42:33 +02:00
disservin
5372f81cc8
SE depth scaling using the previous depth
...
This patch makes the SE depth condition more robust and allows it to scale with completed depth
from a previous search.
At long TC this patch is almost equivalent to https://github.com/official-stockfish/Stockfish/pull/4016 which had
VLTC:
https://tests.stockfishchess.org/tests/view/626abd7e8707aa698c0093a8
Elo: 2.35 +-1.5 (95%) LOS: 99.9%
Total: 40000 W: 10991 L: 10720 D: 18289
Ptnml(0-2): 8, 3534, 12648, 3799, 11
nElo: 5.47 +-3.4 (95%) PairsRatio: 1.08
VLTC multicore:
https://tests.stockfishchess.org/tests/view/6272a6afc8f14123163c1997
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 86808 W: 24165 L: 23814 D: 38829
Ptnml(0-2): 11, 7253, 28524, 7606, 10
however, it is now also gaining at LTC:
LTC:
https://tests.stockfishchess.org/tests/view/627e7cb523c0c72a05b651a9
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 27064 W: 7285 L: 7046 D: 12733
Ptnml(0-2): 8, 2446, 8390, 2675, 13
and should have nearly no influence at STC as depth 27 is rarely reached.
It was noticed that initializing the threshold with MAX_PLY, had an adverse effect,
possibly because the first move is sensitive to this.
closes https://github.com/official-stockfish/Stockfish/pull/4021
closes https://github.com/official-stockfish/Stockfish/pull/4016
Bench: 6481017
2022-05-14 13:17:35 +02:00
Stéphane Nicolet
9eb7b607cf
Reduce depth after score improvement at PV nodes
...
STC:
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 73760 W: 19590 L: 19244 D: 34926
Ptnml(0-2): 285, 8352, 19292, 8634, 317
https://tests.stockfishchess.org/tests/view/626eb2dc9116b52aa83b73da
LTC:
LLR: 2.93 (-2.94,2.94) <0.50,3.00>
Total: 114400 W: 30561 L: 30111 D: 53728
Ptnml(0-2): 68, 11432, 33785, 11812, 103
https://tests.stockfishchess.org/tests/view/626f730859e9c431e0b10b21
closes https://github.com/official-stockfish/Stockfish/pull/4008
bench: 6174823
2022-05-04 07:47:56 +02:00
candirufish
a32d2086bc
Use fail high count for LMR
...
Increase reduction if next ply has a lot of fail high else reset count to 0
Passed STC:
https://tests.stockfishchess.org/tests/view/626ea8299116b52aa83b71f6
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 144288 W: 38377 L: 37902 D: 68009
Ptnml(0-2): 565, 16298, 38054, 16551, 676
Passed LTC:
https://tests.stockfishchess.org/tests/view/626fa0fb79f761bab2e382f0
LLR: 2.98 (-2.94,2.94) <0.50,3.00>
Total: 74872 W: 20050 L: 19686 D: 35136
Ptnml(0-2): 51, 7541, 21893, 7895, 56
closes https://github.com/official-stockfish/Stockfish/pull/4006
bench: 7084802
2022-05-03 17:58:01 +02:00
Stefan Geschwentner
285a79eaa0
Simplify time management.
...
Replace the best move instability adjustment factor by a simpler version which doesn't have a dependency on the iteration depth.
STC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 30800 W: 8232 L: 8073 D: 14495
Ptnml(0-2): 101, 3309, 8444, 3422, 124
https://tests.stockfishchess.org/tests/view/6266c77bc5b924ba22908d30
LTC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 61664 W: 16375 L: 16272 D: 29017
Ptnml(0-2): 40, 5869, 18897, 6000, 26
https://tests.stockfishchess.org/tests/view/6266fc39b3d1812808915f23
closes https://github.com/official-stockfish/Stockfish/pull/3999
Bench: 7729968
2022-05-03 17:54:23 +02:00
candirufish
e1f12aa4e6
Negative extension for ttMove that is less than alpha and value
...
in the context of singular extensions
Passed STC:
https://tests.stockfishchess.org/tests/view/626047e8b03f22647441ade0
LLR: 2.97 (-2.94,2.94) <0.00,2.50>
Total: 50296 W: 13410 L: 13108 D: 23778
Ptnml(0-2): 196, 5548, 13370, 5826, 208
Passed LTC:
https://tests.stockfishchess.org/tests/view/6260a513b03f22647441b970
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 83896 W: 22433 L: 22054 D: 39409
Ptnml(0-2): 49, 8273, 24938, 8626, 62
closes https://github.com/official-stockfish/Stockfish/pull/3995
bench: 7729968
2022-04-22 08:17:22 +02:00
Michael Chaly
e41f727f0f
Simplify away best move count logic
...
the only place where it was used it was true with >99% probability so it seemed to not be doing much any more.
Passed STC:
https://tests.stockfishchess.org/tests/view/625f4778d00da81c22dd4c93
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 85152 W: 22487 L: 22406 D: 40259
Ptnml(0-2): 313, 9035, 23818, 9078, 332
Passed LTC:
https://tests.stockfishchess.org/tests/view/625ff1f1b03f22647441a215
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 66776 W: 17768 L: 17673 D: 31335
Ptnml(0-2): 46, 6200, 20792, 6313, 37
close https://github.com/official-stockfish/Stockfish/pull/3993
bench 7280798
2022-04-22 08:09:40 +02:00
KJE-98
df2f7e7527
Decrease LMR at PV nodes with low depth.
...
This patch lessens the Late Move Reduction at PV nodes with low depth. Previously the affect of depth on LMR was independant of nodeType. The idea behind this patch is that at PV nodes, LMR at low depth is will miss out on potential alpha-raising moves.
Passed STC:
https://tests.stockfishchess.org/tests/view/625aa867d3367522c4b8965c
LLR: 2.93 (-2.94,2.94) <0.00,2.50>
Total: 19360 W: 5252 L: 5006 D: 9102
Ptnml(0-2): 79, 2113, 5069, 2321, 98
Passed LTC:
https://tests.stockfishchess.org/tests/view/625ae844d3367522c4b8a009
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 39264 W: 10636 L: 10357 D: 18271
Ptnml(0-2): 18, 3928, 11473, 4183, 30
closes https://github.com/official-stockfish/Stockfish/pull/3985
bench: 8129754
2022-04-17 21:38:05 +02:00
Topologist
19a90b45bc
Use NNUE in low piece endgames close to the root.
...
This patch enforces that NNUE evaluation is used for endgame positions at shallow depth (depth <= 9).
Classic evaluation will still be used for high imbalance positions when the depth is high or there are many pieces.
Passed STC:
https://tests.stockfishchess.org/tests/view/624c193b3a8a6ac93892dc27
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 255840 W: 68024 L: 67362 D: 120454
Ptnml(0-2): 1074, 27089, 70926, 27763, 1068
Passed LTC:
https://tests.stockfishchess.org/tests/view/624e8675e9e7821808467f77
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 67088 W: 17784 L: 17454 D: 31850
Ptnml(0-2): 45, 6209, 20715, 6521, 54
closes https://github.com/official-stockfish/Stockfish/pull/3978
bench: 6602222
2022-04-12 17:43:50 +02:00
Giacomo Lorenzetti
910cf8b218
Remove pos.capture_or_promotion()
...
This patch replaces `pos.capture_or_promotion()` with `pos.capture()`
and comes after a few attempts with elo-gaining bounds, two of which
failed yellow at LTC
(https://tests.stockfishchess.org/tests/view/622f8f0cc9e950cbfc237024
and
https://tests.stockfishchess.org/tests/view/62319a8bb3b498ba71a6b2dc ).
Passed non-regression STC:
https://tests.stockfishchess.org/tests/view/623aff7eea447151c74828d3
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 246864 W: 65462 L: 65618 D: 115784
Ptnml(0-2): 1201, 28116, 65001, 27866, 1248
Passed non-regression LTC:
https://tests.stockfishchess.org/tests/view/623c1fdcea447151c7484fb0
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 30120 W: 8125 L: 7978 D: 14017
Ptnml(0-2): 22, 2993, 8881, 3144, 20
closes https://github.com/official-stockfish/Stockfish/pull/3968
Bench: 6847732
2022-03-25 20:14:00 +01:00
Stefan Geschwentner
e31f97e3ba
Remove ttPv tree shrinking.
...
Via the ttPv flag an implicit tree of current and former PV nodes is maintained. In addition this tree is grown or shrinked at the leafs dependant on the search results. But now the shrinking step has been removed.
As the frequency of ttPv nodes decreases with depth the shown scaling behavior (STC barely passed but LTC scales well) of the tests was expected.
STC:
LLR: 2.93 (-2.94,2.94) <-2.25,0.25>
Total: 270408 W: 71593 L: 71785 D: 127030
Ptnml(0-2): 1339, 31024, 70630, 30912, 1299
https://tests.stockfishchess.org/tests/view/622fbf9dc9e950cbfc2376d6
LTC:
LLR: 2.96 (-2.94,2.94) <-2.25,0.25>
Total: 34368 W: 9135 L: 8992 D: 16241
Ptnml(0-2): 28, 3423, 10135, 3574, 24
https://tests.stockfishchess.org/tests/view/62305257c9e950cbfc238964
closes https://github.com/official-stockfish/Stockfish/pull/3963
Bench: 7044203
2022-03-19 13:40:35 +01:00
Michael Chaly
eae0f8dd06
Decrease reductions in Lmr for some Pv nodes
...
This patch makes us reduce less in Lmr at pv nodes in case of static eval being far away from static evaluation of position.
Idea is that if it's the case then probably position is pretty complex so we can't be sure about how reliable LMR is so we need to reduce less.
Passed STC:
https://tests.stockfishchess.org/tests/view/6226276aa9d47c8160e81220
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 262696 W: 69944 L: 69239 D: 123513
Ptnml(0-2): 1399, 29702, 68436, 30417, 1394
Passed LTC:
https://tests.stockfishchess.org/tests/view/6226b002a9d47c8160e82b91
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 64008 W: 17320 L: 16982 D: 29706
Ptnml(0-2): 60, 6378, 18811, 6674, 81
closes https://github.com/official-stockfish/Stockfish/pull/3957
bench 6678390
2022-03-08 20:19:42 +01:00
Giacomo Lorenzetti
4ac7d726ec
Sort captures
...
This patch (partially) sort captures in analogy to quiet moves. All
three movepickers are affected, hence `depth` is added as an argument in
probcut's.
Passed STC:
https://tests.stockfishchess.org/tests/view/621a4576da649bba32ef6fd4
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 103848 W: 27884 L: 27473 D: 48491
Ptnml(0-2): 587, 11691, 26974, 12068, 604
Passed LTC:
https://tests.stockfishchess.org/tests/view/621aaa5bda649bba32ef7c2d
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 212032 W: 56420 L: 55739 D: 99873
Ptnml(0-2): 198, 21310, 62348, 21933, 227
closes https://github.com/official-stockfish/Stockfish/pull/3952
Bench: 6833580
2022-03-01 17:51:37 +01:00
Michael Chaly
27139dedac
Adjust usage of LMR for 2nd move in move ordering
...
Current master prohibits usage of LMR for 2nd move at rootNode. This patch also disables LMR for 2nd move not only at rootNode but also at first PvNode that is a reply to rootNode.
passed STC:
https://tests.stockfishchess.org/tests/view/620e8c9026f5b17ec885143a
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 54096 W: 14305 L: 13996 D: 25795
Ptnml(0-2): 209, 6075, 14192, 6342, 230
passed LTC:
https://tests.stockfishchess.org/tests/view/620eb327b1792e8985f81fb8
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 110864 W: 29602 L: 29156 D: 52106
Ptnml(0-2): 112, 11147, 32455, 11619, 99
closes https://github.com/official-stockfish/Stockfish/pull/3940
bench 6820724
2022-02-20 23:01:22 +01:00
Michael Chaly
84b1940fca
Tune search at very long time control
...
This patch is a result of tuning done by user @candirufish after 150k games.
Since the tuned values were really interesting and touched heuristics
that are known for their non-linear scaling I decided to run limited
games LTC match, even if the STC test was really bad (which was expected).
After seeing the results of the LTC match, I also run a VLTC (very long
time control) SPRTtest, which passed.
The main difference is in extensions: this patch allows much more
singular/double extensions, both in terms of allowing them at lower
depths and with lesser margins.
Failed STC:
https://tests.stockfishchess.org/tests/view/620d66643ec80158c0cd3b46
LLR: -2.94 (-2.94,2.94) <0.00,2.50>
Total: 4968 W: 1194 L: 1398 D: 2376
Ptnml(0-2): 47, 633, 1294, 497, 13
Performed well at LTC in a fixed-length match:
https://tests.stockfishchess.org/tests/view/620d66823ec80158c0cd3b4a
ELO: 3.36 +-1.8 (95%) LOS: 100.0%
Total: 30000 W: 7966 L: 7676 D: 14358
Ptnml(0-2): 36, 2936, 8755, 3248, 25
Passed VLTC SPRT test:
https://tests.stockfishchess.org/tests/view/620da11a26f5b17ec884f939
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 4400 W: 1326 L: 1127 D: 1947
Ptnml(0-2): 13, 309, 1348, 526, 4
closes https://github.com/official-stockfish/Stockfish/pull/3937
Bench: 6318903
2022-02-17 20:45:21 +01:00
Michael Chaly
3ec6e1d245
Big search tuning (version 2)
...
One more tuning - this one includes newly introduced heuristics and
some other parameters that were not included in previous one. Result
of 400k games at 20+0.2 "as is". Tuning is continuing since there is
probably a lot more elo to gain.
STC:
https://tests.stockfishchess.org/tests/view/620782edd71106ed12a497d1
LLR: 2.99 (-2.94,2.94) <0.00,2.50>
Total: 38504 W: 10260 L: 9978 D: 18266
Ptnml(0-2): 142, 4249, 10230, 4447, 184
LTC:
https://tests.stockfishchess.org/tests/view/6207a243d71106ed12a49d07
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 25176 W: 6793 L: 6546 D: 11837
Ptnml(0-2): 20, 2472, 7360, 2713, 23
closes https://github.com/official-stockfish/Stockfish/pull/3931
Bench: 4784796
2022-02-13 01:05:27 +01:00
Michael Chaly
b0b31558a2
Big search tuning
...
Most credits for this patch should go to @candirufish.
Based on his big search tuning (1M games at 20+0.1s)
https://tests.stockfishchess.org/tests/view/61fc7a6ed508ec6a1c9f4b7d
with some hand polishing on top of it, which includes :
a) correcting trend sigmoid - for some reason original tuning resulted in it being negative. This heuristic was proven to be worth some elo for years so reversing it sign is probably some random artefact;
b) remove changes to continuation history based pruning - this heuristic historically was really good at providing green STCs and then failing at LTC miserably if we tried to make it more strict, original tuning was done at short time control and thus it became more strict - which doesn't scale to longer time controls;
c) remove changes to improvement - not really indended :).
passed STC
https://tests.stockfishchess.org/tests/view/6203526e88ae2c84271c2ee2
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 16840 W: 4604 L: 4363 D: 7873
Ptnml(0-2): 82, 1780, 4449, 2033, 76
passed LTC
https://tests.stockfishchess.org/tests/view/620376e888ae2c84271c35d4
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 17232 W: 4771 L: 4542 D: 7919
Ptnml(0-2): 14, 1655, 5048, 1886, 13
closes https://github.com/official-stockfish/Stockfish/pull/3926
bench 5030992
2022-02-09 17:17:00 +01:00
Michael Chaly
08ac4e9db5
Do less depth reduction in null move pruning for complex positions
...
This patch makes us reduce less depth in null move pruning if complexity is high enough.
Thus, null move pruning now depends in two distinct ways on complexity,
while being the only search heuristic that exploits complexity so far.
passed STC
https://tests.stockfishchess.org/tests/view/61fde60fd508ec6a1c9f7754
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 170000 W: 45555 L: 45027 D: 79418
Ptnml(0-2): 760, 19352, 44359, 19658, 871
passed LTC
https://tests.stockfishchess.org/tests/view/61fe91febf46cb834cbd5c90
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 145272 W: 39182 L: 38651 D: 67439
Ptnml(0-2): 127, 14864, 42157, 15327, 161
closes https://github.com/official-stockfish/Stockfish/pull/3923
bench 4461945
2022-02-07 17:30:35 +01:00
Michael Chaly
4d3950c6eb
Reintroduce razoring
...
Razoring was simplified away some years ago, this patch reintroduces it in a slightly different form.
Now for low depths if eval is far below alpha we check if qsearch can push it above alpha - and if it can't we return a fail low.
passed STC
https://tests.stockfishchess.org/tests/view/61fbf968d508ec6a1c9f3274
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 226120 W: 61106 L: 60472 D: 104542
Ptnml(0-2): 1118, 25592, 59080, 26078, 1192
passed LTC
https://tests.stockfishchess.org/tests/view/61fcc569d508ec6a1c9f5617
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 113128 W: 30851 L: 30397 D: 51880
Ptnml(0-2): 114, 11483, 32926, 11917, 124
closes https://github.com/official-stockfish/Stockfish/pull/3921
bench 4684080
2022-02-05 07:40:21 +01:00
Michael Chaly
95d7369e54
Introduce movecount pruning for quiet check evasions in qsearch
...
Idea of this patch is that we usually don't consider quiet check evasions as "good" ones and prefer capture based ones instead. So it makes sense to think that if in qsearch 2 quiet check evasions failed to produce anything good 3rd and further ones wouldn't be good either.
passed STC
https://tests.stockfishchess.org/tests/view/61fc1b1ed508ec6a1c9f397c
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 58800 W: 15947 L: 15626 D: 27227
Ptnml(0-2): 273, 6568, 15462, 6759, 338
passed LTC
https://tests.stockfishchess.org/tests/view/61fcc56dd508ec6a1c9f5619
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 89544 W: 24208 L: 23810 D: 41526
Ptnml(0-2): 81, 9038, 26134, 9440, 79
closes https://github.com/official-stockfish/Stockfish/pull/3920
bench 4830082
2022-02-05 07:38:30 +01:00
Michael Chaly
90d051952f
Do stats updates after LMR for captures
...
Since captures that are in LMR use continuation histories of corresponding quiet moves it makes sense to update this histories if this capture passes LMR by analogy to existing logic for quiet moves.
Passed STC
https://tests.stockfishchess.org/tests/view/61f367eef7fba9f1a4f1318b
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 208464 W: 56006 L: 55407 D: 97051
Ptnml(0-2): 964, 23588, 54655, 23935, 1090
Passed LTC
https://tests.stockfishchess.org/tests/view/61f41e34f7fba9f1a4f15241
LLR: 2.96 (-2.94,2.94) <0.50,3.00>
Total: 69144 W: 18793 L: 18441 D: 31910
Ptnml(0-2): 65, 6982, 20142, 7302, 81
closes https://github.com/official-stockfish/Stockfish/pull/3910
bench 4637392
2022-01-29 08:58:12 +01:00
Michael Chaly
8b4afcf8f7
Scale child node futility pruning with previous move history.
...
Idea is to do more futility pruning if previous move has bad histories and less if it has good histories.
passed STC
https://tests.stockfishchess.org/tests/view/61e3757fbabab931824e0db7
LLR: 2.96 (-2.94,2.94) <0.00,2.50>
Total: 156816 W: 42282 L: 41777 D: 72757
Ptnml(0-2): 737, 17775, 40913, 18212, 771
passed LTC
https://tests.stockfishchess.org/tests/view/61e43496928632f7813a5535
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 349968 W: 94612 L: 93604 D: 161752
Ptnml(0-2): 300, 35934, 101550, 36858, 342
closes https://github.com/official-stockfish/Stockfish/pull/3903
bench 4720954
2022-01-25 07:27:52 +01:00
J. Oster
9083050be6
Simplify limiting extensions.
...
Replace the current method for limiting extensions to avoid search getting stuck
with a much simpler method.
the test position in 73018a0337fixes #3815 where the search now makes progress with rootDepth
shows robust behavior in a d10 search for 1M positions.
passed STC
https://tests.stockfishchess.org/tests/view/61e303e3babab931824dfb18
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 57568 W: 15449 L: 15327 D: 26792
Ptnml(0-2): 243, 6211, 15779, 6283, 268
passed LTC
https://tests.stockfishchess.org/tests/view/61e3586cbabab931824e091c
LLR: 2.96 (-2.94,2.94) <-2.25,0.25>
Total: 128200 W: 34632 L: 34613 D: 58955
Ptnml(0-2): 124, 12559, 38710, 12588, 119
closes https://github.com/official-stockfish/Stockfish/pull/3899
Bench: 4550528
2022-01-22 10:48:24 +01:00
Rui Coelho
2b0372319d
Use average complexity for time management
...
This patch is a variant of the idea by locutus2 (https://tests.stockfishchess.org/tests/view/61e1f24cb1f9959fe5d88168 ) to adjust the total time depending on the average complexity of the position.
Passed STC
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 39664 W: 10765 L: 10487 D: 18412
Ptnml(0-2): 162, 4213, 10837, 4425, 195
https://tests.stockfishchess.org/tests/view/61e2df8b65a644da8c9ea708
Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 127656 W: 34505 L: 34028 D: 59123
Ptnml(0-2): 116, 12435, 38261, 12888, 128
https://tests.stockfishchess.org/tests/view/61e31db5babab931824dff5e
closes https://github.com/official-stockfish/Stockfish/pull/3892
Bench: 4464962
2022-01-17 19:48:23 +01:00
Rui Coelho
7678d63cf2
Use complexity in search
...
This patch uses the complexity measure (from #3875 ) as a heuristic for null move pruning.
Hopefully, there may be room to use it in other pruning techniques.
I would like to thank vondele and locutus2 for the feedback and suggestions during testing.
Passed STC
LLR: 2.95 (-2.94,2.94) <0.00,2.50>
Total: 35000 W: 9624 L: 9347 D: 16029
Ptnml(0-2): 156, 3894, 9137, 4143, 170
https://tests.stockfishchess.org/tests/view/61dda784c65bf87d6c45ab80
Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 230776 W: 64227 L: 63454 D: 103095
Ptnml(0-2): 1082, 23100, 66380, 23615, 1211
https://tests.stockfishchess.org/tests/view/61ddd0cf3ddbc32543e72c2b
Closes https://github.com/official-stockfish/Stockfish/pull/3890
Bench: 4464962
2022-01-13 22:25:01 +01:00
Michael Chaly
44b1ba89a9
Adjust pruning constants
...
This patch is a modification of original tuning done by vondele that failed yellow.
Value differences are divided by 2.
Passed STC
https://tests.stockfishchess.org/tests/view/61d918239fea7913d9c64cdf
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 98968 W: 26248 L: 25858 D: 46862
Ptnml(0-2): 392, 11085, 26156, 11443, 408
Passed LTC
https://tests.stockfishchess.org/tests/view/61d99e3c9fea7913d9c663e4
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 215232 W: 58191 L: 57492 D: 99549
Ptnml(0-2): 271, 22124, 62138, 22801, 282
closes https://github.com/official-stockfish/Stockfish/pull/3885
bench 4572746
2022-01-10 19:35:53 +01:00
Brad Knox
ad926d34c0
Update copyright years
...
Happy New Year!
closes https://github.com/official-stockfish/Stockfish/pull/3881
No functional change
2022-01-06 15:45:45 +01:00
lonfom169
0b41887527
Simplify away rangeReduction
...
Remove rangeReduction, introduced in [#3717 ](https://github.com/official-stockfish/Stockfish/pull/3717 ),
as it seemingly doesn't bring enough ELO anymore. It might be interesting to add
new forms of reduction or tune the reduction formula in the future.
STC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 45008 W: 12114 L: 11972 D: 20922
Ptnml(0-2): 174, 5031, 11952, 5173, 174
https://tests.stockfishchess.org/tests/view/61d08b7b069ca917749c9f6f
LTC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 30792 W: 8235 L: 8086 D: 14471
Ptnml(0-2): 24, 3162, 8882, 3297, 31
https://tests.stockfishchess.org/tests/view/61d0a6ad069ca917749ca420
closes https://github.com/official-stockfish/Stockfish/pull/3878
Bench: 4048312
2022-01-02 17:49:44 +01:00
lonfom169
061f98a9e3
Smooth out doDeeperSearch
...
Adjust threshold based on the difference between newDepth and LMR depth.
With more reduction, bigger fail-high is required in order to perform the deeper search.
STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.50>
Total: 93576 W: 24133 L: 23758 D: 45685
Ptnml(0-2): 260, 10493, 24935, 10812, 288
https://tests.stockfishchess.org/tests/view/61cbb5cee68b2a714b6eaf09
LTC:
LLR: 2.94 (-2.94,2.94) <0.50,3.00>
Total: 109280 W: 28198 L: 27754 D: 53328
Ptnml(0-2): 60, 11225, 31637, 11647, 71
https://tests.stockfishchess.org/tests/view/61cc03fee68b2a714b6ec091
closes https://github.com/official-stockfish/Stockfish/pull/3877
Bench: 4464723
2021-12-31 07:44:15 +01:00
bmc4
93b14a17d1
Don't direct prune a move if it's a retake
...
STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.50>
Total: 36304 W: 9499 L: 9226 D: 17579
Ptnml(0-2): 96, 4102, 9508, 4325, 121
https://tests.stockfishchess.org/tests/view/61c7069ae68b2a714b6dca27
LTC:
LLR: 2.95 (-2.94,2.94) <0.50,3.00>
Total: 93824 W: 24478 L: 24068 D: 45278
Ptnml(0-2): 70, 9644, 27082, 10038, 78
https://tests.stockfishchess.org/tests/view/61c725fee68b2a714b6dcfa2
closes https://github.com/official-stockfish/Stockfish/pull/3871
Bench: 4106806
2021-12-27 16:43:44 +01:00
bmc4
88f17a814d
Update Elo estimates for terms in search
...
This updates estimates from 2yr ago #2401 , and adds missing terms.
All tests run at 10+0.1 (STC), 20000 games, error bars +- 1.8 Elo, book 8moves_v3.png.
A table of Elo values with the links to the corresponding tests can be found at the PR
closes https://github.com/official-stockfish/Stockfish/pull/3868
Non-functional Change
2021-12-21 13:47:57 +01:00
bmc4
22e92d23d2
Remove Capture history pruning
...
Fixed number of games. (book: 8moves_v3.png):
ELO: -0.69 +-1.8 (95%) LOS: 22.1%
Total: 20000 W: 1592 L: 1632 D: 16776
Ptnml(0-2): 44, 1194, 7566, 1150, 46
https://tests.stockfishchess.org/tests/view/61bb8eb657a0d0f327c30ce8
STC:
LLR: 2.94 (-2.94,2.94) <-2.25,0.25>
Total: 139976 W: 36039 L: 36036 D: 67901
Ptnml(0-2): 435, 16138, 36885, 16049, 481
https://tests.stockfishchess.org/tests/view/61be731857a0d0f327c39ea2
LTC:
LLR: 2.95 (-2.94,2.94) <-2.25,0.25>
Total: 70656 W: 18284 L: 18189 D: 34183
Ptnml(0-2): 34, 7317, 20529, 7416, 32
https://tests.stockfishchess.org/tests/view/61bf39b657a0d0f327c3c37b
closes https://github.com/official-stockfish/Stockfish/pull/3867
bench: 4281737
2021-12-21 13:42:33 +01:00
