| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: mstembera
Date: Sat Oct 23 12:21:17 2021 +0200 Timestamp: 1634984477 Simplify away ValueListInserter plus minor cleanups STC: https://tests.stockfishchess.org/tests/view/616f059b40f619782fd4f73f LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 84992 W: 21244 L: 21197 D: 42551 Elo +0.19 Ptnml(0-2): 279, 9005, 23868, 9078, 266 closes https://github.com/official-stockfish/Stockfish/pull/3749 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stefan Geschwentner
Date: Thu Oct 21 12:42:30 2021 +0200 Timestamp: 1634812950 Double extend more often via LMR Allow for first three moves always a two plies deeper LMR search. STC: LLR: 2.96 (-2.94,2.94) <-2.50,0.50> Total: 206096 W: 51966 L: 52093 D: 102037 Elo -0.21 Ptnml(0-2): 664, 23817, 54293, 23530, 744 https://tests.stockfishchess.org/tests/view/616f197d40f619782fd4f75a LTC: LLR: 2.93 (-2.94,2.94) <-2.50,0.50> Total: 62384 W: 15567 L: 15492 D: 31325 Elo +0.42 Ptnml(0-2): 40, 6633, 17777, 6696, 46 https://tests.stockfishchess.org/tests/view/616ffa1b4f0b65a0e231e682 closes https://github.com/official-stockfish/Stockfish/pull/3752 Bench: 6154836 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: bmc4
Date: Thu Oct 21 08:43:43 2021 +0200 Timestamp: 1634798623 Simplify null move search condition Remove `ss->ttPv` condition on null move search condition STC: LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 80832 W: 20276 L: 20221 D: 40335 Elo +0.24 Ptnml(0-2): 267, 9335, 21168, 9368, 278 https://tests.stockfishchess.org/tests/view/616ed4a0942d40685e3237c6 LTC: LLR: 2.95 (-2.94,2.94) <-2.50,0.50> Total: 54184 W: 13464 L: 13377 D: 27343 Elo +0.56 Ptnml(0-2): 37, 5758, 15435, 5805, 57 https://tests.stockfishchess.org/tests/view/616ef71f40f619782fd4f72d closes https://github.com/official-stockfish/Stockfish/pull/3750 bench: 6201607 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: bmc4
Date: Tue Oct 19 22:14:39 2021 +0200 Timestamp: 1634674479 Adjust TTdepth acceptance on early cutoff STC: LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 63784 W: 16185 L: 15917 D: 31682 Elo +1.46 Ptnml(0-2): 231, 7309, 16531, 7603, 218 https://tests.stockfishchess.org/tests/view/616ed03a942d40685e3237c0 LTC: LLR: 2.93 (-2.94,2.94) <0.50,3.50> Total: 12728 W: 3268 L: 3072 D: 6388 Elo +5.35 Ptnml(0-2): 8, 1298, 3563, 1480, 15 https://tests.stockfishchess.org/tests/view/616ef156942d40685e32380a closes https://github.com/official-stockfish/Stockfish/pull/3748 bench: 7050445 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: bmc4
Date: Tue Oct 19 22:09:47 2021 +0200 Timestamp: 1634674187 Simplify evaluate condition on search Remove condition for MOVE_NULL on search. STC: LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 47544 W: 11968 L: 11864 D: 23712 Elo +0.76 Ptnml(0-2): 150, 5535, 12318, 5599, 170 https://tests.stockfishchess.org/tests/view/616e37143799eb91f1f071ee LTC: LLR: 2.93 (-2.94,2.94) <-2.50,0.50> Total: 67472 W: 16938 L: 16870 D: 33664 Elo +0.35 Ptnml(0-2): 49, 7119, 19331, 7189, 48 https://tests.stockfishchess.org/tests/view/616e3fab3799eb91f1f071f1 closes https://github.com/official-stockfish/Stockfish/pull/3746 bench: 5255771 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: bmc4
Date: Mon Oct 18 21:00:08 2021 +0200 Timestamp: 1634583608 Simplify probCutCount away Simplify away the limitation in number of moves in probCut. STC: LLR: 2.96 (-2.94,2.94) <-2.50,0.50> Total: 286768 W: 71888 L: 72133 D: 142747 Elo -0.30 Ptnml(0-2): 983, 33084, 75471, 32887, 959 https://tests.stockfishchess.org/tests/view/616c9b9b90e1312a3cd0ef0a LTC: LLR: 2.95 (-2.94,2.94) <-2.50,0.50> Total: 69312 W: 17243 L: 17176 D: 34893 Elo +0.34 Ptnml(0-2): 42, 7452, 19614, 7493, 55 https://tests.stockfishchess.org/tests/view/616cebbf4f95b438f7a85f93 closes https://github.com/official-stockfish/Stockfish/pull/3745 bench: 5005810 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stefano Cardanobile
Date: Mon Oct 18 20:45:47 2021 +0200 Timestamp: 1634582747 Reformat Eval::evaluate() Non functional simplification: the goal of this patch is to make the style in the evaluate() function similar to the rest of the code. passed STC: LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 95608 W: 24058 L: 24026 D: 47524 Elo +0.12 Ptnml(0-2): 292, 10379, 26396, 10479, 258 https://tests.stockfishchess.org/tests/view/616c64fd99b580bf37797e4f closes https://github.com/official-stockfish/Stockfish/pull/3744 Non-functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stéphane Nicolet
Date: Sun Oct 17 17:54:39 2021 +0200 Timestamp: 1634486079 Remove noLMRExtension flag This simplification patch removes the noLMRExtension flag. It was introduced in June (see following link for that commit), but does not seem to be necessary anymore. Link: https://github.com/official-stockfish/Stockfish/commit/e1f181ee643dcaa92c606b74b3abd23dede136cd STC: LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 21200 W: 5369 L: 5228 D: 10603 Elo +2.31 Ptnml(0-2): 67, 2355, 5616, 2494, 68 https://tests.stockfishchess.org/tests/view/616c03d299b580bf37797dcb LTC: LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 37536 W: 9387 L: 9278 D: 18871 Elo +1.01 Ptnml(0-2): 23, 3988, 10643, 4085, 29 https://tests.stockfishchess.org/tests/view/616c10f499b580bf37797ddd closes https://github.com/official-stockfish/Stockfish/pull/3743 Bench: 4792969 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stéphane Nicolet
Date: Sun Oct 17 12:29:11 2021 +0200 Timestamp: 1634466551 Allow some LMR double extensions Allow some LMR double extensions for the second and third sons of each node. STC: LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 170320 W: 42608 L: 42187 D: 85525 Elo +0.86 Ptnml(0-2): 516, 19635, 44422, 20086, 501 https://tests.stockfishchess.org/tests/view/616a9e3899b580bf37797cf4 LTC: LLR: 2.93 (-2.94,2.94) <0.50,3.50> Total: 74400 W: 18783 L: 18423 D: 37194 Elo +1.68 Ptnml(0-2): 46, 7812, 21129, 8162, 51 https://tests.stockfishchess.org/tests/view/616b378499b580bf37797d61 closes https://github.com/official-stockfish/Stockfish/pull/3742 Bench: 4877152 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stefano Cardanobile
Date: Fri Oct 15 14:57:01 2021 +0200 Timestamp: 1634302621 Smooth improving Smooth dependency on improvement margin in null move search. STC LLR: 2.93 (-2.94,2.94) <-0.50,2.50> Total: 17384 W: 4468 L: 4272 D: 8644 Elo +3.92 Ptnml(0-2): 42, 1919, 4592, 2079, 60 https://tests.stockfishchess.org/tests/view/61689b8a1e5f6627cc1c0fdc LTC LLR: 2.94 (-2.94,2.94) <0.50,3.50> Total: 45648 W: 11525 L: 11243 D: 22880 Elo +2.15 Ptnml(0-2): 26, 4731, 13036, 4997, 34 https://tests.stockfishchess.org/tests/view/6168a12c1e5f6627cc1c0fe3 It would be interesting to test if the other pruning/reduction heuristics in master which are using the improving variable (ie the sign of improvement) could benefit from a smooth function of the improvement value (or maybe a Relu of the improvement value). closes https://github.com/official-stockfish/Stockfish/pull/3740 Bench: 4916775 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Joost VandeVondele
Date: Thu Oct 14 09:58:03 2021 +0200 Timestamp: 1634198283 Compute ttCapture earlier Compute ttCapture earlier, and reuse. passed STC: LLR: 2.93 (-2.94,2.94) <-2.50,0.50> Total: 74128 W: 18640 L: 18578 D: 36910 Elo +0.29 Ptnml(0-2): 224, 7970, 20649, 7962, 259 https://tests.stockfishchess.org/tests/view/615dd9fa1a32f4036ac7fc4d closes https://github.com/official-stockfish/Stockfish/pull/3734 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: bmc4
Date: Thu Oct 14 09:47:20 2021 +0200 Timestamp: 1634197640 Simplify ttHitAverage away Simplify ttHitAverage away, which was introduced in the following commit: [here](https://github.com/BM123499/Stockfish/commit/fe124896b241b4791454fd151da10101ad48f6d7) A few tweaks with Elo gaining bounds have been tried to keep the code, but they all failed: https://tests.stockfishchess.org/tests/view/61656f7683dd501a05b0b292 https://tests.stockfishchess.org/tests/view/6165c0ca83dd501a05b0b2ca https://tests.stockfishchess.org/tests/view/6165bf9683dd501a05b0b2c8 https://tests.stockfishchess.org/tests/view/6165719483dd501a05b0b29b https://tests.stockfishchess.org/tests/view/6166c7fd83dd501a05b0b353 https://tests.stockfishchess.org/tests/view/6166c63b83dd501a05b0b350 STC: LLR: 2.94 (-2.94,2.94) <-2.50,0.50> Total: 58504 W: 14781 L: 14694 D: 29029 Elo +0.52 Ptnml(0-2): 175, 6718, 15426, 6711, 222 https://tests.stockfishchess.org/tests/view/6165112c83dd501a05b0b257 LTC: LLR: 2.96 (-2.94,2.94) <-2.50,0.50> Total: 33480 W: 8448 L: 8332 D: 16700 Elo +1.20 Ptnml(0-2): 21, 3569, 9447, 3679, 24 https://tests.stockfishchess.org/tests/view/61656fcf83dd501a05b0b294 change https://github.com/official-stockfish/Stockfish/pull/3739 bench: 4540339 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Joseph Ellis
Date: Wed Oct 13 23:34:23 2021 +0200 Timestamp: 1634160863 Simplify multi-cut condition Now that the multi-cut condition is safer, we can avoid the cost of the sub-search. STC: https://tests.stockfishchess.org/tests/view/6165fd9283dd501a05b0b2fe LLR: 2.93 (-2.94,2.94) <-2.50,0.50> Total: 18648 W: 4745 L: 4600 D: 9303 Elo +2.70 Ptnml(0-2): 47, 2111, 4887, 2208, 71 LTC: https://tests.stockfishchess.org/tests/view/616629ea83dd501a05b0b320 LLR: 2.96 (-2.94,2.94) <-2.50,0.50> Total: 41704 W: 10407 L: 10302 D: 20995 Elo +0.87 Ptnml(0-2): 35, 4425, 11823, 4538, 31 closes https://github.com/official-stockfish/Stockfish/pull/3738 Bench: 5905086 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Michael Chaly
Date: Sat Oct 9 09:59:33 2021 +0200 Timestamp: 1633766373 Reduce more if multiple moves exceed alpha Idea of this patch is the following: in case we already have four moves that exceeded alpha in the current node, the probability of finding fifth should be reasonably low. Note that four is completely arbitrary - there could and probably should be some tweaks, both in tweaking best move count threshold for more reductions and tweaking how they work - for example making more reductions with best move count linearly. passed STC: https://tests.stockfishchess.org/tests/view/615f614783dd501a05b0aee2 LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 141816 W: 36056 L: 35686 D: 70074 Elo +0.91 Ptnml(0-2): 499, 15131, 39273, 15511, 494 passed LTC: https://tests.stockfishchess.org/tests/view/615fdff683dd501a05b0af35 LLR: 2.94 (-2.94,2.94) <0.50,3.50> Total: 68536 W: 17221 L: 16891 D: 34424 Elo +1.67 Ptnml(0-2): 38, 6573, 20725, 6885, 47 closes https://github.com/official-stockfish/Stockfish/pull/3736 Bench: 6131513 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: xoto10
Date: Thu Oct 7 09:41:57 2021 +0200 Timestamp: 1633592517 Small clean-up, Sept 2021 Closes https://github.com/official-stockfish/Stockfish/pull/3485 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stéphane Nicolet
Date: Wed Oct 6 12:04:35 2021 +0200 Timestamp: 1633514675 Capping stat bonus at 2000 This patch updates the stat_bonus() function (used in the history tables to help move ordering), keeping the same quadratic for small depths but changing the values for depth >= 9: The old bonus formula was increasing from zero at depth 1 to 4100 at depth 14, then used the strange, small value of 73 for all depths >= 15. The new bonus formula increases from 0 at depth 1 to 2000 at depth 8, then keeps 2000 for all depths >= 8. passed STC: LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 169624 W: 42875 L: 42454 D: 84295 Elo +0.86 Ptnml(0-2): 585, 19340, 44557, 19729, 601 https://tests.stockfishchess.org/tests/view/615bd69e9d256038a969b97c passed LTC: LLR: 3.07 (-2.94,2.94) <0.50,3.50> Total: 37336 W: 9456 L: 9191 D: 18689 Elo +2.47 Ptnml(0-2): 20, 3810, 10747, 4067, 24 https://tests.stockfishchess.org/tests/view/615c75d99d256038a969b9b2 closes https://github.com/official-stockfish/Stockfish/pull/3731 Bench: 6261865 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Joost VandeVondele
Date: Wed Oct 6 11:57:34 2021 +0200 Timestamp: 1633514254 Improve the Chess960 correction for cornered bishops As Chess960 patches can not be tested on fishtest, this was locally tuned and tested: Elo: 2.36 +- 1.07 LOS: 0.999992 closes https://github.com/official-stockfish/Stockfish/pull/3730 Bench: 5714575 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: J. Oster
Date: Wed Oct 6 11:53:33 2021 +0200 Timestamp: 1633514013 Time-management fix in MultiPV mode. When playing games in MultiPV mode we must take care to only track the best move changing for the first PV line. Otherwise, SF will spend most of its time for the initial moves after the book exit. This has been observed and reported on Discord, but can also be seen in games played in Stefan Pohl's MultiPV experiment. Tested with MultiPV=4. STC: https://tests.stockfishchess.org/tests/view/615c24b59d256038a969b990 LLR: 2.95 (-2.94,2.94) <-0.50,2.50> Total: 1744 W: 694 L: 447 D: 603 Elo +49.54 Ptnml(0-2): 32, 125, 358, 278, 79 LTC: https://tests.stockfishchess.org/tests/view/615c31769d256038a969b993 LLR: 2.94 (-2.94,2.94) <0.50,3.50> Total: 2048 W: 723 L: 525 D: 800 Elo +33.70 Ptnml(0-2): 10, 158, 511, 314, 31 closes https://github.com/official-stockfish/Stockfish/pull/3729 Bench: 5714575 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Michael Chaly
Date: Sun Oct 3 11:28:19 2021 +0200 Timestamp: 1633253299 Increase reductions with thread count Respin of multi-thread idea that was simplified away recently: basically doing more reductions with thread count since Lazy SMP naturally widens search. With drawish book this idea got simplified away but with less drawish book it again gains elo, maybe trying to reinstall other ideas that were simplified away previously can be beneficial. passed STC LLR: 2.96 (-2.94,2.94) <-0.50,2.50> Total: 39736 W: 10205 L: 9986 D: 19545 Elo +1.91 Ptnml(0-2): 45, 4254, 11064, 4447, 58 https://tests.stockfishchess.org/tests/view/615750702d02f48db3961b00 passed LTC LLR: 2.97 (-2.94,2.94) <0.50,3.50> Total: 60352 W: 15530 L: 15218 D: 29604 Elo +1.80 Ptnml(0-2): 24, 5900, 18016, 6212, 24 https://tests.stockfishchess.org/tests/view/6157d8935488e26ea5eace7f closes https://github.com/official-stockfish/Stockfish/pull/3724 Bench 5714575 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Michael Chaly
Date: Sun Sep 26 06:58:14 2021 +0200 Timestamp: 1632632294 Extend quiet tt moves at PvNodes Idea is to extend some quiet ttMoves if a lot of things indicate that the transposition table move is going to be a good move: 1) move being a killer - so being the best move in nearby node; 2) reply continuation history is really good. This is basically saying that move is good "in general" in this position, that it is a good reply to the opponent move and that it was the best in this position somewhere in search - so extending it makes a lot of sense. In general in past year we had a lot of extensions of different types, maybe there is something more in it :) passed STC LLR: 2.96 (-2.94,2.94) <-0.50,2.50> Total: 42944 W: 10932 L: 10695 D: 21317 Elo +1.92 Ptnml(0-2): 141, 4869, 11210, 5116, 136 https://tests.stockfishchess.org/tests/view/614cca8e7bdc23e77ceb89f0 passed LTC LLR: 2.93 (-2.94,2.94) <0.50,3.50> Total: 156848 W: 39473 L: 38893 D: 78482 Elo +1.28 Ptnml(0-2): 125, 16327, 44913, 16961, 98 https://tests.stockfishchess.org/tests/view/614cf93d7bdc23e77ceb8a13 closes https://github.com/official-stockfish/Stockfish/pull/3719 Bench: 5714575 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stéphane Nicolet
Date: Sat Sep 25 22:12:17 2021 +0200 Timestamp: 1632600737 Reduction instead of cutoff In master, during singular move analysis, when both the transposition value and a reduced search for the other moves seem to indicate a fail high, we heuristically prune the whole subtree and return an fail high score. This patch is a little bit more cautious in this case, and instead of the risky cutoff, we now search the ttMove with a reduced depth (by two plies). STC: https://tests.stockfishchess.org/tests/view/614dafe07bdc23e77ceb8a89 LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 46728 W: 11909 L: 11666 D: 23153 Elo +1.81 Ptnml(0-2): 181, 5288, 12168, 5561, 166 LTC: https://tests.stockfishchess.org/tests/view/614dc84abe4c07e0ecac3c95 LLR: 2.94 (-2.94,2.94) <0.50,3.50> Total: 74520 W: 18809 L: 18450 D: 37261 Elo +1.67 Ptnml(0-2): 45, 7735, 21346, 8084, 50 closes https://github.com/official-stockfish/Stockfish/pull/3718 Bench: 5499262 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: OfekShochat
Date: Fri Sep 24 23:17:48 2021 +0200 Timestamp: 1632518268 Range reductions adding reductions for when the delta between the static eval and the child's eval is consistently low. passed STC https://tests.stockfishchess.org/html/live_elo.html?614d7b3c7bdc23e77ceb8a5d LLR: 2.95 (-2.94,2.94) <-0.50,2.50> Total: 88872 W: 22672 L: 22366 D: 43834 Elo +1.20 Ptnml(0-2): 343, 10150, 23117, 10510, 316 passed LTC https://tests.stockfishchess.org/html/live_elo.html?614daf3e7bdc23e77ceb8a82 LLR: 2.93 (-2.94,2.94) <0.50,3.50> Total: 24368 W: 6153 L: 5928 D: 12287 Elo +3.21 Ptnml(0-2): 13, 2503, 6937, 2708, 23 closes https://github.com/official-stockfish/Stockfish/pull/3717 Bench: 5443950 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stéphane Nicolet
Date: Thu Sep 23 23:24:28 2021 +0200 Timestamp: 1632432268 Tweak doubly singular condition (Topo's patch) This patch relax a little bit the condition for doubly singular moves (ie moves that are so forced that we think that they deserve a local double extension of the search). We lower the margin and allow up to six such double extensions in the path between the root and the critical node. Original idea by Siad Daboul (@TopoIogist) in PR #3709 Tested with the previous commit: passed STC: LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 33048 W: 8458 L: 8236 D: 16354 Elo +2.33 Ptnml(0-2): 120, 3701, 8660, 3923, 120 https://tests.stockfishchess.org/tests/view/614b24347bdc23e77ceb88fe passed LTC: LLR: 2.95 (-2.94,2.94) <0.50,3.50> Total: 54176 W: 13712 L: 13406 D: 27058 Elo +1.96 Ptnml(0-2): 36, 5653, 15399, 5969, 31 https://tests.stockfishchess.org/tests/view/614b3b727bdc23e77ceb8911 closes https://github.com/official-stockfish/Stockfish/pull/3714 Bench: 5792377 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Stéphane Nicolet
Date: Thu Sep 23 23:19:06 2021 +0200 Timestamp: 1632431946 Detect search explosions This patch detects some search explosions (due to double extensions in search.cpp) which can happen in some pathological positions, and takes measures to ensure progress in search even for these pathological situations. While a small number of double extensions can be useful during search (for example to resolve a tactical sequence), a sustained regime of double extensions leads to search explosion and a non-finishing search. See the discussion in https://github.com/official-stockfish/Stockfish/pull/3544 and the issue https://github.com/official-stockfish/Stockfish/issues/3532 . The implemented algorithm is the following: a) at each node during search, store the current depth in the stack. Double extensions are by definition levels of the stack where the depth at ply N is strictly higher than depth at ply N-1. b) during search, calculate for each thread a running average of the number of double extensions in the last 4096 visited nodes. c) if one thread has more than 2% of double extensions for a sustained period of time (6 millions consecutive nodes, or about 4 seconds on my iMac), we decide that this thread is in an explosion state and we calm down this thread by preventing it to do any double extension for the next 6 millions nodes. To calculate the running averages, we also introduced a auxiliary class generalizing the computations of ttHitAverage variable we already had in code. The implementation uses an exponential moving average of period 4096 and resolution 1/1024, and all computations are done with integers for efficiency. ----------- Example where the patch solves a search explosion: ``` ./stockfish ucinewgame position fen 8/Pk6/8/1p6/8/P1K5/8/6B1 w - - 37 130 go infinite ``` This algorithm does not affect search in normal, non-pathological positions. We verified, for instance, that the usual bench is unchanged up to depth 20 at least, and that the node numbers are unchanged for a search of the starting position at depth 32. ------------- See https://github.com/official-stockfish/Stockfish/pull/3714 Bench: 5575265 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers + AVX2 Windows x64 for modern computers Windows x64 + SSSE3 Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers + AVX2 Linux x64 for modern computers Linux x64 + SSSE3 Linux x64 | Author: Michael Chaly
Date: Tue Sep 21 19:48:40 2021 +0200 Timestamp: 1632246520 Combo of various parameter tweaks Combination of parameter tweaks in search, evaluation and time management. Original patches by snicolet xoto10 lonfom169 and Vizvezdenec. Includes: * Use bigger grain of positional evaluation more frequently (up to 1 exchange difference in non-pawn-material); * More extra time according to increment; * Increase margin for singular extensions; * Do more aggresive parent node futility pruning. Passed STC https://tests.stockfishchess.org/tests/view/6147deab3733d0e0dd9f313d LLR: 2.94 (-2.94,2.94) <-0.50,2.50> Total: 45488 W: 11691 L: 11450 D: 22347 Elo +1.84 Ptnml(0-2): 145, 5208, 11824, 5395, 172 Passed LTC https://tests.stockfishchess.org/tests/view/6147f1d53733d0e0dd9f3141 LLR: 2.94 (-2.94,2.94) <0.50,3.50> Total: 62520 W: 15808 L: 15482 D: 31230 Elo +1.81 Ptnml(0-2): 43, 6439, 17960, 6785, 33 closes https://github.com/official-stockfish/Stockfish/pull/3710 bench 5575265 see source |