| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Brian Sheppard
Date: Sun Oct 6 00:57:00 2019 +0200 Timestamp: 1570316220 Eliminate ONE_PLY Simplification that eliminates ONE_PLY, based on a suggestion in the forum that support for fractional plies has never been used, and @mcostalba's openness to the idea of eliminating it. We lose a little bit of type safety by making Depth an integer, but in return we simplify the code in search.cpp quite significantly. No functional change ------------------------------------------ The argument favoring eliminating ONE_PLY: * The term “ONE_PLY” comes up in a lot of forum posts (474 to date) https://groups.google.com/forum/?fromgroups=#!searchin/fishcooking/ONE_PLY%7Csort:relevance * There is occasionally a commit that breaks invariance of the code with respect to ONE_PLY https://groups.google.com/forum/?fromgroups=#!searchin/fishcooking/ONE_PLY%7Csort:date/fishcooking/ZIPdYj6k0fk/KdNGcPWeBgAJ * To prevent such commits, there is a Travis CI hack that doubles ONE_PLY and rechecks bench * Sustaining ONE_PLY has, alas, not resulted in any improvements to the engine, despite many individuals testing many experiments over 5 years. The strongest argument in favor of preserving ONE_PLY comes from @locutus: “If we use par example ONE_PLY=256 the parameter space is increases by the factor 256. So it seems very unlikely that the optimal setting is in the subspace of ONE_PLY=1.” There is a strong theoretical impediment to fractional depth systems: the transposition table uses depth to determine when a stored result is good enough to supply an answer for a current search. If you have fractional depths, then different pathways to the position can be at fractionally different depths. In the end, there are three separate times when a proposal to remove ONE_PLY was defeated by the suggestion to “give it a few more months.” So… it seems like time to remove this distraction from the community. See the pull request here: https://github.com/official-stockfish/Stockfish/pull/2289 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Sat Oct 5 11:15:24 2019 +0200 Timestamp: 1570266924 Fix compare function in previous patch Bench: 4012371 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: mstembera
Date: Sat Oct 5 10:45:37 2019 +0200 Timestamp: 1570265137 Remove temporary shelter array Remove temporary array of shelters and avoid iterating over it each time to find if the shelter values after castling are better than the current value. Work done on top of https://github.com/official-stockfish/Stockfish/pull/2277 Speed benchmark did not measure any difference. No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Moez Jellouli
Date: Wed Oct 2 13:37:00 2019 +0200 Timestamp: 1570016220 More accurate pawn attack span definition Tweak the pawn attack span for backward pawns and the zone behind opponent opposing pawns. This is important in positional play and one of weaknesses of the engine in recent high level games. STC LLR: -2.95 (-2.94,2.94) [0.50,4.50] Total: 66843 W: 14884 L: 14717 D: 37242 Elo +0.87 http://tests.stockfishchess.org/tests/view/5d8dcb1b0ebc590f3beb2956 LTC LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 77699 W: 12993 L: 12602 D: 52104 Elo +1.75 http://tests.stockfishchess.org/tests/view/5d8de9bc0ebc590f3beb3d00 See discussion in https://github.com/official-stockfish/Stockfish/pull/2332 Bench: 4012371 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Joost VandeVondele
Date: Wed Oct 2 01:43:02 2019 +0200 Timestamp: 1569973382 Adjust reductions based on the number of threads In lazySMP it makes sense to prune a little more, as multiple threads search wider. We thus increase the prefactor of the reductions slowly as a function of the threads. The prefactor of the log(threads) term is a parameter, this pull request uses 1/2 after testing. passed STC @ 8threads: LLR: 2.96 (-2.94,2.94) [0.50,4.50] Total: 118125 W: 23151 L: 22462 D: 72512 Elo +2.03 http://tests.stockfishchess.org/tests/view/5d8bbf4d0ebc59509180f217 passed LTC @ 8threads: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 67546 W: 10630 L: 10279 D: 46637 Elo +1.81 http://tests.stockfishchess.org/tests/view/5d8c463b0ebc5950918167e8 passed ~LTC @ 14threads: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 74271 W: 12421 L: 12040 D: 49810 Elo +1.78 http://tests.stockfishchess.org/tests/view/5d8db1f50ebc590f3beb24ef Note: A larger prefactor (1) passed similar tests at STC and LTC (8 threads), while a very large one (2) passed STC quickly but failed LTC (8 threads). For the single-threaded case there is no functional change. Closes https://github.com/official-stockfish/Stockfish/pull/2337 Bench: 4088701 Fixup: remove redundant code. see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: protonspring
Date: Tue Oct 1 09:12:57 2019 +0200 Timestamp: 1569913977 Remove ThreatByRank This is a functional simplification that removes ThreatByRank. STC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 48009 W: 10630 L: 10560 D: 26819 Elo +0.51 http://tests.stockfishchess.org/tests/view/5d92095c0ebc594fb88eb61e LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 18682 W: 3177 L: 3053 D: 12452 Elo +2.31 http://tests.stockfishchess.org/tests/view/5d9231120ebc594fb88ebacd Moving forward, it's possible that ThreatByMinor and ThreatByRook could be combined, but I haven't really contemplated that yet. Closes https://github.com/official-stockfish/Stockfish/pull/2336 bench 4088701 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Joost VandeVondele
Date: Mon Sep 30 10:16:43 2019 +0200 Timestamp: 1569831403 Remove depth dependence in value_draw(). The condition "depth >= 4 * ONE_PLY" does not seem needed at this point. passed STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 32751 W: 7178 L: 7078 D: 18495 Elo +1.06 http://tests.stockfishchess.org/tests/view/5d8e46660ebc590f3bebad5e passed LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 31693 W: 5299 L: 5196 D: 21198 Elo +1.13 http://tests.stockfishchess.org/tests/view/5d8e4b4f0ebc590f3bebb165 Bench: 4062526 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: 31m059
Date: Fri Sep 27 12:46:47 2019 +0200 Timestamp: 1569581207 Extend castling independently of singular extension A curious feature of Stockfish's current extension code is its repeated use of "else if." In most cases, this makes no functional difference, because no more than one extension is applied; once one extension has been applied, the remaining ones can be safely ignored. However, if most singular extension search conditions are true, except "value < singularBeta", no non-singular extensions (e.g., castling) can be performed! Three tests were submitted, for three of Stockfish's four non-singular extensions. I excluded the shuffle extension, because historically there have been concerns about the fragility of its conditions, and I did not want to risk causing any serious search problems. - Modifying the passed pawn extension appeared roughly neutral at STC. At best, it appeared to be an improvement of less than 1 Elo. - Modifying check extension performed very poorly at STC - Modifying castling extension (this patch) produced a long "yellow" run at STC (insufficient to pass, but positive score) and a strong LTC. In simple terms, prior to this patch castling extension was occasionally not applied during search--on castling moves. The effect of this patch is to perform castling extension on more castling moves. It does so without adding any code complexity, simply by replacing an "else if" with "if" and reordering some existing code. STC: LLR: -2.96 (-2.94,2.94) [0.00,4.00] Total: 108114 W: 23877 L: 23615 D: 60622 Elo +0.84 http://tests.stockfishchess.org/tests/view/5d8d86bd0ebc590f3beb0c88 LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 20862 W: 3517 L: 3298 D: 14047 Elo +3.65 http://tests.stockfishchess.org/tests/view/5d8d99cd0ebc590f3beb1899 Bench: 3728191 -------- Where do we go from here? - It seems strange to me that check extension performed so poorly -- clearly some of the singular extension conditions are also very important for check extension. I am not an expert in search, and I do not have any intuition about which of the eight conditions is/are the culprit. I will try a succession of eight STC tests to identify the relevant conditions, then try to replicate this PR for check extension. - Recent tests interacting with the castle extension may deserve retesting. I will shortly resubmit a few of my recent castling extension tweaks, rebased on this PR/commit. My deepest thanks to @noobpwnftw for the extraordinary CPU donation, and to all our other fishtest volunteers, who made it possible for a speculative LTC to pass in 70 minutes! Closes https://github.com/official-stockfish/Stockfish/pull/2331 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Alain SAVARD
Date: Fri Sep 27 12:37:49 2019 +0200 Timestamp: 1569580669 Simplify RookOnPawn Remove the RookOnPawn logic (for rook on rank 5 and above aligning with pawns on same row or file) which was overlapping with a few other parameters. Inspired by @31m059 interesting result hinting that a direct attack on pawns instead of PseudoAttacks might work. http://tests.stockfishchess.org/tests/view/5d89a7c70ebc595091801b8d After a few attempts by me and @31m059, and some long STC greens but red LTC, as a proof of concept I first tried a local SPSA at VSTC trying to tune related rook psqt rows, and mainly some rook related stuff in evaluate.cpp. Result was STC green, but still red LTC, Finally a 100M fishtest SPSA at LTC proved successful both at STC and LTC. All this was possible with the awesome fishtest contributors. At some point, I had 850 workers on the last test ! Run as a simplification STC http://tests.stockfishchess.org/tests/view/5d8d68f40ebc590f3beaf171 LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 7399 W: 1693 L: 1543 D: 4163 Elo +7.04 LTC http://tests.stockfishchess.org/tests/view/5d8d70270ebc590f3beaf63c LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 41617 W: 6981 L: 6894 D: 27742 Elo +0.73 Closes https://github.com/official-stockfish/Stockfish/pull/2329 bench: 4037914 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Joost VandeVondele
Date: Fri Sep 27 00:16:49 2019 +0200 Timestamp: 1569536209 Remove custom mutex implementation As part of the investigation of the hang caused by an incorrect implementation of condition_variable in libwinpthread, it was realized that our custom Mutex implementation is no longer needed. Prior to lazySMP this custom implementation resulted in a 30% speedup, but now no speed difference can be measured as no mutex is used on the hot path in lazySMP. https://github.com/official-stockfish/Stockfish/issues/2291 https://github.com/official-stockfish/Stockfish/issues/2309#issuecomment-533733393 https://github.com/official-stockfish/Stockfish/issues/2309#issuecomment-533737515 The interest of this patch is that it removes platform-specific code, which is always less tested. No functional change. see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Thu Sep 26 23:27:48 2019 +0200 Timestamp: 1569533268 Restore development version (revert previous commit) Revert the previous patch now that the binary for the super-final of TCEC season 16 has been sent. Maybe the feature of showing the name of compiler will be added to the master branch in the future. But we may use a cleaner way to code it, see some ideas using the Makefile approach at the end of pull request #2327 : https://github.com/official-stockfish/Stockfish/pull/2327 Bench: 3618154 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Wed Sep 25 22:28:51 2019 +0200 Timestamp: 1569443331 Temporary patch to show the compiler for TCEC submission This patch shows a description of the compiler used to compile Stockfish, when starting from the console. Usage: ``` ./stockfish compiler ``` Example of output: ``` Stockfish 240919 64 POPCNT by T. Romstad, M. Costalba, J. Kiiski, G. Linscott Compiled by clang++ 9.0.0 on Apple __VERSION__ macro expands to: 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.38) ``` No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Tue Sep 24 12:54:02 2019 +0200 Timestamp: 1569322442 Increase weight for supported pawns This patch changes the weight for counting supports of pawns from 17 to 21. Hopefully Stockfish will accept to play a bit more of closed or semi-closed positions. STC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 13822 W: 3158 L: 2939 D: 7725 Elo +5.51 http://tests.stockfishchess.org/tests/view/5d89c3a10ebc595091802379 LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 63066 W: 10590 L: 10236 D: 42240 Elo +1.95 http://tests.stockfishchess.org/tests/view/5d89ca7f0ebc595091802680 Future work: try to tweak the evaluation to better understand the French structures. Closes https://github.com/official-stockfish/Stockfish/pull/2326 Bench: 3618154 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: nickpelling
Date: Tue Sep 24 10:05:54 2019 +0200 Timestamp: 1569312354 Clarify the mapping of files to queenside This patch replaces the obscure expressions mapping files ABCDEFGH to ABCDDCBA by explicite calls to an auxiliary function: old: f = min(f, ~f) new: f = map_to_queenside(f) We used the Golbolt web site (https://godbolt.org) to check that the current code for the auxiliary function is optimal. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 30292 W: 6756 L: 6651 D: 16885 Elo +1.20 http://tests.stockfishchess.org/tests/view/5d8676720ebc5971531d6aa1 Achieved with a bit of help from Sopel97, snicolet and vondele, thanks everyone! Closes https://github.com/official-stockfish/Stockfish/pull/2325 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: xoto10
Date: Mon Sep 23 09:50:34 2019 +0200 Timestamp: 1569225034 Encourage rook lift to third rank This change to the Rook psqt encourages rook lifts to the third rank on the two center files. STC 10+0.1 th 1 : LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 40654 W: 9028 L: 8704 D: 22922 Elo +2.77 http://tests.stockfishchess.org/tests/view/5d885da60ebc5906dd3e9fcd LTC 60+0.6 th 1 : LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 56963 W: 9530 L: 9196 D: 38237 Elo +2.04 http://tests.stockfishchess.org/tests/view/5d88618c0ebc5906dd3ea45f Thanks to @snicolet for mentioning that Komodo does this a lot and Stockfish doesn't, which gave me the idea for this patch, and to @noobpwnftw for providing cores to fishtest which allowed very quick testing. Future work: perhaps this can be refined somehow to encourage this on other files, my attempts have failed. Closes https://github.com/official-stockfish/Stockfish/pull/2322 Bench: 3950249 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Mon Sep 23 09:10:28 2019 +0200 Timestamp: 1569222628 Revert "Clarify the mapping of files to queenside" This reverts commit 7756344d5d2b93970e7cd423f8cbf6fb1da11b74. see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Mon Sep 23 08:54:20 2019 +0200 Timestamp: 1569221660 Clarify the mapping of files to queenside Author: @nickpelling We replace in the code the obscure expressions mapping files ABCDEFGH to ABCDDCBA by an explicite call to an auxiliary function : old: f = min(f, ~f) new: f = map_to_queenside(f) We used the Golbolt web site (https://godbolt.org) to find the optimal code for the auxiliary function. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 30292 W: 6756 L: 6651 D: 16885 Elo +1.20 http://tests.stockfishchess.org/tests/view/5d8676720ebc5971531d6aa1 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Joost VandeVondele
Date: Mon Sep 23 07:29:00 2019 +0200 Timestamp: 1569216540 More random draw evaluations Use the randomized draw function value_draw() also for draw evalutions. This extends the earlier commit https://github.com/official-stockfish/Stockfish/commit/97d2cc9a9c1c4b6ff1b470676fa18c7fc6509886 which did this only for 3folds. As in that case, this test was yellow at STC and LTC, but green at VLTC, indicative of the fact that the higher the drawrate, the more likely this idea is beneficial. STC: LLR: -2.96 (-2.94,2.94) [0.50,4.50] Total: 83573 W: 18584 L: 18335 D: 46654 Elo +1.04 http://tests.stockfishchess.org/tests/view/5d84e44d0ebc5971531d4f94 LTC: LLR: -2.96 (-2.94,2.94) [0.00,3.50] Total: 92252 W: 15240 L: 15160 D: 61852 Elo +0.30 http://tests.stockfishchess.org/tests/view/5d865dd90ebc5971531d68e1 VLTC: 120+1.2 @ 2th LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 51902 W: 7323 L: 7028 D: 37551 Elo +1.97 http://tests.stockfishchess.org/tests/view/5d8763620ebc595f57c22b15 Closes https://github.com/official-stockfish/Stockfish/pull/2321 Bench: 3441237 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: protonspring
Date: Mon Sep 23 07:12:32 2019 +0200 Timestamp: 1569215552 Simplify connected pawn scoring When scoring the connected pawns, replace the intricate ternary expressions choosing the coefficient by a simpler addition of boolean conditions: ` value = Connected * (2 + phalanx - opposed) ` This is the map showing the old coefficients and the new ones: ``` phalanx and unopposed: 3x -> 3x phalanx and opposed: 1.5x -> 2x not phalanx and unopposed: 2x -> 2x not phalanx and opposed: 1x -> 1x ``` STC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 11354 W: 2579 L: 2437 D: 6338 Elo +4.35 http://tests.stockfishchess.org/tests/view/5d8151f00ebc5971531d244f LTC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 41221 W: 7001 L: 6913 D: 27307 Elo +0.74 http://tests.stockfishchess.org/tests/view/5d818f930ebc5971531d26d6 Bench: 3959889 blah see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Joost VandeVondele
Date: Mon Sep 23 06:47:59 2019 +0200 Timestamp: 1569214079 Acknowledge fishtest authors Explicitly acknowledge fishtest authors. Their efforts are almost invisible, but essential for the project. Many thanks to https://github.com/glinscott/fishtest/blob/master/AUTHORS ! No functional change. see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: noobpwnftw
Date: Mon Sep 16 15:09:45 2019 +0200 Timestamp: 1568639385 Raise stack size to 8MB for pthreads It seems there is no other way to specify stack size on std::thread than linker flags and the effective flags are named differently in many toolchains. On toolchains where pthread is always available, this patch changes the stack size change in our C++ code via pthread to ensure a minimum stack size of 8MB, instead of relying on linker defaults which may be platform-specific. Also raises default stack size on OSX to current Linux default (8MB) just to be safe. Closes https://github.com/official-stockfish/Stockfish/pull/2303 No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Mon Sep 16 01:37:39 2019 +0200 Timestamp: 1568590659 Scale down endgame factor when shuffling This patch decreases the endgame scale factor using the 50 moves counter. Looking at some games with this patch, it seems to have two effects on the playing style: 1) when no progress can be made in late endgames (for instance in fortresses or opposite bishops endgames) the evaluation will be largely tamed down towards a draw value. 2) more interestingly, there is also a small effect in the midgame play because Stockfish will panic a little bit if there are more than four consecutive shuffling moves with an advantage: the engine will try to move a pawn or to exchange a piece to keep the advantage, so the follow-ups of the position will be discovered earlier by the alpha-beta search. passed STC: LLR: 2.95 (-2.94,2.94) [0.50,4.50] Total: 23017 W: 5080 L: 4805 D: 13132 Elo +4.15 http://tests.stockfishchess.org/tests/view/5d7e4aef0ebc59069c36fc74 passed LTC: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 30746 W: 5171 L: 4911 D: 20664 Elo +2.94 http://tests.stockfishchess.org/tests/view/5d7e513d0ebc59069c36ff26 Pull request: https://github.com/official-stockfish/Stockfish/pull/2304 Bench: 4272173 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Vizvezdenec
Date: Sun Sep 15 00:32:54 2019 +0200 Timestamp: 1568500374 Introduce midgame initiative This patch finally introduces something that was tried for years: midgame score dependance on complexity of position. More precisely, if the position is very simplified and the complexity measure calculated in the initiative() function is inferior to -50 by an amount d, then we add this value d to the midgame score. One example of play of this patch will be (again!) 4 vs 3 etc same flank endgames where sides have a lot of non-pawn material: 4 vs 3 draw mostly remains the same draw even if we add a lot of equal material to both sides. STC run was stopped after 200k games (and not converging): LLR: -1.75 (-2.94,2.94) [0.50,4.50] Total: 200319 W: 44197 L: 43310 D: 112812 Elo +1.54 http://tests.stockfishchess.org/tests/view/5d7cfdb10ebc5902d386572c passed LTC: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 41051 W: 6858 L: 6570 D: 27623 Elo +2.44 http://tests.stockfishchess.org/tests/view/5d7d14680ebc5902d3866196 This is the first and not really precise version, a lot of other stuff can be tried on top of it (separate complexity for middlegame, some more terms, even simple retuning of values). Bench: 4248476 see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: Stéphane Nicolet
Date: Sat Sep 14 08:33:00 2019 +0200 Timestamp: 1568442780 Assorted trivial cleanups No functional change see source |
| Windows x64 for Haswell CPUs Windows x64 for modern computers Windows x64 Windows 32 Linux x64 for Haswell CPUs Linux x64 for modern computers Linux x64 | Author: 31m059
Date: Sat Sep 14 07:47:05 2019 +0200 Timestamp: 1568440025 Use queens of either color in RookOnQueenFile The recently-added RookOnQueenFile evaluation term (36e4a86) provided a bonus for placing our rook on the same file as an enemy queen. Here, we relax a condition in this bonus, broadening its effect to any queen. It is also strategically desirable to place the rook on the same file as a friendly queen, so the restriction on the queen's color is removed. STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 66856 W: 14847 L: 14815 D: 37194 Elo +0.17 http://tests.stockfishchess.org/tests/view/5d7b3c6a0ebc5902d385bcf5 LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 86786 W: 14264 L: 14248 D: 58274 Elo +0.06 http://tests.stockfishchess.org/tests/view/5d7b4e9b0ebc5902d385c178 Closes https://github.com/official-stockfish/Stockfish/pull/2302 Bench: 3703909 see source |