| 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: Tue Nov 12 01:27:06 2019 +0100 Timestamp: 1573518426 Remove explicit moveCount pruning The removed lines approximately duplicate equivalent logic in the movePicker. Adjust the futility_move_count to componsate for some difference (the movePicker prunes one iteration of the move loop later). Passed STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 8114 W: 1810 L: 1663 D: 4641 Elo +6.30 http://tests.stockfishchess.org/tests/view/5dc6afe60ebc5902562bd318 Passed LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 89956 W: 14473 L: 14460 D: 61023 Elo +0.05 http://tests.stockfishchess.org/tests/view/5dc6bdcf0ebc5902562bd3c0 Closes https://github.com/official-stockfish/Stockfish/pull/2407 Bench: 4256440 --------------------- How to continue from there? It would be interesting to see if we can extract some Elo gain from the new futility_move_count formula, for instance by somehow incorporating the final -1 in the 5 constant, or adding a linear term to the quadratics... ``` futility_move_count = (5 + depth * depth) * (1 + improving) / 2 - 1 ``` 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: Tue Nov 12 01:18:54 2019 +0100 Timestamp: 1573517934 Sequencing tweak in tbprobe() Followup of "issue" #2372, which was in fact a small speed-up proposal by user @d3vv for the probing code of tablebases. See comments on this issue where it was proven by Alin Savard that the proposed change is more efficient on average than master on all type of sequences it will usually be called. Note that on gcc 4.3, this will produce a bogus warning which was solved with ulterior gcc versions: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43949 Closes https://github.com/official-stockfish/Stockfish/issues/2372 Closes https://github.com/official-stockfish/Stockfish/pull/2379 Non 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: Tue Nov 12 01:09:57 2019 +0100 Timestamp: 1573517397 Fix incorrect mate score. Current master 648c7ec25db2040c0af34dd846dfa3f57af5ad0a will generate an incorrect mate score for: ``` setoption name Hash value 8 setoption name Threads value 1 position fen 8/1p2KP2/1p4q1/1Pp5/2P5/N1Pp1k2/3P4/1N6 b - - 76 40 go depth 49 ``` even though the position is a draw. Generally, SF tries to display only proven mate scores, so this is a bug. This was posted http://www.talkchess.com/forum3/viewtopic.php?f=2&t=72166 by Uri Blass, with the correct analysis that this must be related to the 50 moves draw rule being ignored somewhere. Indeed, this is possible as positions and there eval are stored in the TT, without reference to the 50mr counter. Depending on the search path followed a position can thus be mate or draw in the TT (GHI or Graph history interaction). Therefore, to prove mate lines, the TT content has to be used with care. Rather than ignoring TT content in general or for mate scores (which impact search or mate finding), it is possible to be more selective. In particular, @WOnder93 suggested to only ignore the TT if the 50mr draw ply is closer than the mate ply. This patch implements this idea, by clamping the eval in the TT to +-VALUE_MATED_IN_MAX_PLY. This retains the TTmove, but causes a research of these lines (with the current 50mr counter) as needed. This patch hardly ever affects search (as indicated by the unchanged bench), but fixes the testcase. As the conditions are very specific, also mate finding will almost never be less efficient (testing welcome). It was also shown to pass STC and LTC non-regression testing, in a form using if/then/else instead of ternary operators: STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 93605 W: 15346 L: 15340 D: 62919 Elo +0.02 http://tests.stockfishchess.org/tests/view/5db45bb00ebc5908127538d4 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 33873 W: 7359 L: 7261 D: 19253 Elo +1.01 http://tests.stockfishchess.org/tests/view/5db4c8940ebc5902d6b146fc closes https://github.com/official-stockfish/Stockfish/issues/2370 Bench: 4362323 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 Nov 6 11:07:38 2019 +0100 Timestamp: 1573034858 Revert "Rook PSQT Tuned" This reverts the previous commit. The PSQT changes in this previous commit originated from tests against quite an old version of master which did not include the other PSQT changes of 474d133 for the other pieces, and there might be some unknown interactions between the PSQT tables. So we made a non-regression test of the last commit against the last-but-one commit. This test failed, leading to the revert decision. Failed non-regression test: LLR: -2.96 (-2.94,2.94) [-3.00,1.00] Total: 95536 W: 15047 L: 15347 D: 65142 Elo -1.09 http://tests.stockfishchess.org/tests/view/5dc0ba1d0ebc5904493b0112 Closes https://github.com/official-stockfish/Stockfish/pull/2395 Bench: 4362323 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: SFisGOD
Date: Tue Nov 5 00:15:23 2019 +0100 Timestamp: 1572909323 Rook PSQT Tuned This patch uses about half the changes of the SPSA tuning run: http://tests.stockfishchess.org/tests/view/5dba93d30ebc5925b64ed3bf About a month ago, xoto10's patch raised the mg value of the third rank center files from -1 to 7 to encourage rook lifts to the third rank. About three days later, Rocky's patch lowered this value from 7 to 3. This patch raises that again from 3 to 12 and ends up greater than the original rook lift patch. Passed STC: LLR: 2.95 (-2.94,2.94) [-1.50,4.50] Total: 104094 W: 22573 L: 22161 D: 59360 Elo +1.38 http://tests.stockfishchess.org/tests/view/5dbc77f20ebc5925b64ef1d0 Passed LTC: LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 168291 W: 27410 L: 26777 D: 114104 Elo +1.31 http://tests.stockfishchess.org/tests/view/5dbd9f1e0ebc5925b64f0647 Bench: 4707799 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: MichaelB7
Date: Tue Nov 5 00:01:49 2019 +0100 Timestamp: 1572908509 Remove shuffle extension It was noted in an earlier patch that all of the positions below needed the Shuffle Detection idea to be solved: 3r4/p3r1pk/PpBb1pRp/1KpPpP1P/2P1P1R1/8/8/8 b - - 32 86 8/8/8/1k6/2p5/p1K5/N2B2r1/8 b - - 59 109 1r4k1/1r1bq3/4p1p1/3pPpPp/pNpN1P1P/P1PnQ3/1PK5/1R3R2 b - - 13 82 5k2/3b4/5p2/p1p1pPp1/PpPpP1Pp/1P1P3P/8/3R1K2 w - - 20 1 But Stockfish has envolved a bit since the Shuffle Detection patch introduction, and this patch proves Stockfish is able to solves these drawn positions without it, even on single core without EGTB. Passed STC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 14231 W: 3114 L: 2978 D: 8139 Elo +3.32 http://tests.stockfishchess.org/tests/view/5dbe1a610ebc5925b64f09d9 Passed LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 42781 W: 6917 L: 6831 D: 29033 Elo +0.70 http://tests.stockfishchess.org/tests/view/5dbe24c20ebc5925b64f0a7a Passed VLTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 32556 W: 4573 L: 4469 D: 23514 Elo +1.11 http://tests.stockfishchess.org/tests/view/5dbec3830ebc5925b64f11aa Closes https://github.com/official-stockfish/Stockfish/pull/2394 Bench: 4362323 ---------------------------- Example of search by Michael Byrne for the FEN position: q1B5/1P1q4/8/8/8/6R1/8/1K1k4 w - - 0 1 This position is win for white and the only moves that wins is Rg1 - all other moves either draw or lose. With single core and 1024M hash, it is solved without shuffle detection in 38 seconds on my machine (with no EGTB). This was the position that was locked in a loop in the initial shuffle detection patch! ``` dep score nodes time (not shown: tbhits knps seldep) 50 +1.71 298.9M 2:43.63 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke5 Kb2 Kf4 Bd1 Qe5+ Kb1 Qe4+ Ka2 Qd5+ Rb3 Qd2+ Ka3 Qc1+ Kb4 Qc7 Ka4 Qb8 Rb6 Ke5 Kb3 Qg8+ Kb4 Qf8+ Ka5 Qb8 Bb3 Kd4 Kb4 Qf8+ Ka4 Qb8 Ka5 K <snip> 49 +1.68 288.5M 2:38.35 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke5 Kb2 Kf4 Bd1 Qe5+ Kb1 Qe4+ Ka2 Qd5+ Rb3 Qd2+ Ka3 Qc1+ Kb4 Qc7 Ka4 Qb8 Rb6 Ke5 Kb3 Qg8+ Kb4 Qf8+ Ka5 Qb8 Bb3 Kd4 Kb4 Ke3 Be6 Ke4 Bc4 Ke <snip> 48 +1.78 228.5M 2:01.93 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke5 Kb2 Kf4 Bd1 Qe5+ Kb1 Qe4+ Ka2 Qd5+ Rb3 Qd2+ Ka3 Qa5+ Kb2 Qe5+ Ka2 Qb8 Rb5 Ke3 Kb1 Ke4 Bb3 Kf4 Be6 Ke3 Rb4 Kd3 Kb2 Ke3 Bd5 Qe5+ Kc2 Qh <snip> 46 +1.49 198.4M 1:44.89 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke5 Kb2 Kf4 Bd1 Qe5+ Kb1 Qe4+ Ka2 Qd5+ Rb3 Qd2+ Ka3 Qc1+ Kb4 Qc7 Ka4 Qb8 Rb6 Qe8+ Rb5 Qb8 Bc2 Qa7+ Kb3 Qe3+ Kc4 Qe6+ Kb4 Qd6+ Kb3 Qb8 Rb4 <snip> 45 +1.45 154.5M 1:20.75 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke3 Bg2 Kd4 Rb5 Kc4 Bf1+ Kd4 Kb2 Qh2+ Kb3 Qg3+ Ka4 Qb8 Be2 Ke3 Bc4 Kf4 Kb4 Qd6+ Kc3 Qb8 Kc2 Ke4 Be6 Qh2+ Kb3 Qg3+ Ka4 Qb8 Bb3 Kd4 Bd5 Ke3 <snip> 44 +1.36 141.9M 1:14.40 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Qd6 Rc2+ Kd3 Be2+ Ke3 Rb2 Qb8 Bd1 Ke4 Rb5 Kd4 Bf3 Kc4 Be2+ Kc3 Rb6 Kd2 Bc4 Kc3 Bd5 Kd4 Bg2 Ke5 Kb2 Kd4 Rb5 Kc4 Bf1+ Kd4 Be2 Ke4 Bc4 Qh2+ Kb3 Qg3+ Ka4 Qb8 Bd5+ Kd4 Be6 Ke4 <snip> 43 +1.36 134.1M 1:10.46 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Qd6 Rc2+ Kd3 Be2+ Ke3 Rb2 Qb8 Bd1 Ke4 Rb5 Kd4 Bf3 Kc4 Be2+ Kc3 Rb6 Kd2 Bc4 Kc3 Be6 Kd4 Rb5 Kc3 Bf7 Kd4 Kb2 Ke4 Kb3 Kf4 Kc3 Ke4 Kb2 Qh2+ Kb3 Qg3+ Ka4 Qb8 Rb4+ Ke5 Rb6 Kf4 <snip> 42 +1.36 118.7M 1:01.60 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Qd6 Rc2+ Kd3 Be2+ Ke3 Rb2 Qb8 Bd1 Ke4 Rb5 Kd4 Bf3 Kc4 Be2+ Kc3 Rb6 Kd2 Bc4 Kc3 Be6 Kd4 Rb5 Kc3 Bf7 Kd4 Kb2 Ke4 Bc4 Qh2+ Kb3 Qg3+ Ka4 Qb8 Bd5+ Kd4 Bb3 Qa7+ Kb4 Qb8 Bc4 Ke4 <snip> 41 +1.38 110.3M 0:56.80 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Qd6 Rc2+ Kd3 Be2+ Ke3 Rb2 Qb8 Bd1 Ke4 Rb5 Kd4 Bf3 Kc4 Be2+ Kc3 Rb6 Kd2 Bc4 Kc3 Be6 Kd4 Rb5 Kc3 Bd5 Kd4 Ba2 Ke4 Be6 Kd4 Kb2 Qh2+ Kb3 Qb8 Bc4 Ke3 Kc3 Qh8+ Kb4 Qb2+ Ka4 Qa1+ <snip> 39 +1.25 87.3M 0:44.48 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke5 Kb2 Kf4 Bd1 Kg5 Kb1 Kf5 Bb3 Ke5 Kb2 Kd4 Rb5 Qh2+ Bc2 Qb8 Bd1 Kc4 Be2+ Kd4 Kc2 Ke3 Bd1 Kd4 Kb3 Qg3+ Ka4 Qb8 Bb3 Kc3 Rb6 Kd4 Kb5 Ke5 K 38 +1.25 82.0M 0:41.90 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kd4 Rb5 Kc4 Be2+ Kc3 Rb6 Kd4 Bf3 Ke5 Kb2 Kf4 Bd1 Kg5 Kb1 Kf5 Bb3 Ke5 Kb2 Kd4 Rb5 Qh2+ Bc2 Qb8 Kb3 Qg3+ Ka4 Qb8 Bb3 Kc3 Rb6 Kd4 Kb5 Ke5 Kb4 Kd4 Be6 Kd3 Bd5 Kd4 Bf3 Ke5 Be <snip> 37 +0.13 79.3M 0:40.44 Rg1+ Kd2 Rg2+ Kc3 Rc2+ Kb3 Rb2+ Kc3 Bxd7 Qf8 Ba4 Qb8 Bd1 Kc4 Bf3 Kd4 Rb5 Kc4 Rb6 Kd4 Rb2 Ke5 Rb3 Kd6 Rb5 Ke6 Rb4 Kd6 Kc2 Kc5 Kb3 Kd6 Be4 Ke7 Kc3 Qc7+ Kd3 Qg3+ Kc2 Qf2+ Kb3 Qe3+ Ka2 Qa7+ Kb2 Qb8 Kb3 Kd6 Bf3 Qg8+ Ka3 Kc7 b8=R Qx 37 +0.67! 78.3M 0:39.90 Rg1+! 37 +0.47! 77.0M 0:39.18 Rg1+! 37 +0.32! 76.8M 0:39.11 Rg1+! 37 +0.23! 76.8M 0:39.07 Rg1+! 36 +0.57! 76.1M 0:38.72 Rg1+! 36 +0.37! 75.8M 0:38.59 Rg1+! 36 +0.23! 75.7M 0:38.51 Rg1+! 36 +0.13! 75.6M 0:38.49 Rg1+! 35 +0.03? 58.0M 0:29.84 bxa8=Q Qb5+? ``` 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: Mon Nov 4 23:50:14 2019 +0100 Timestamp: 1572907814 Make Square and Bitboard operators commutative As Stockfish developers, we aim to make our code as legible and as close to simple English as possible. However, one of the more notable exceptions to this rule concerns operations between Squares and Bitboards. Prior to this pull request, AND, OR, and XOR were only defined when the Bitboard was the first operand, and the Square the second. For example, for a Bitboard b and Square s, "b & s" would be valid but "s & b" would not. This conflicts with natural reasoning about logical operators, both mathematically and intuitively, which says that logical operators should commute. More dangerously, however, both Square and Bitboard are defined as integers "under the hood." As a result, code like "s & b" would still compile and give reasonable bench values. This trap occasionally ensnares even experienced Stockfish developers, but it is especially dangerous for new developers not aware of this peculiarity. Because there is no compilation or runtime error, and a reasonable bench, only a close review by approvers can spot this error when a test has been submitted--and many times, these bugs have slipped past review. This is by far the most common logical error on Fishtest, and has wasted uncountable STC games over the years. However, it can be fixed by adding three non-functional lines of code. In this patch, we define the operators when the operands are provided in the opposite order, i.e., we make AND, OR, and XOR commutative for Bitboards and Squares. Because these are inline methods and implemented identically, the executable does not change at all. This patch has the small side-effect of requiring Squares to be explicitly cast to integers before AND, OR, or XOR with integers. This is only performed twice in Stockfish's source code, and again does not change the executable at all (since Square is an enum defined as an integer anyway). For demonstration purposes, this pull request also inverts the order of one AND and one OR, to show that neither the bench nor the executable change. (This change can be removed before merging, if preferred.) I hope that this pull request significantly lowers the barrier-of-entry for new developer to join the Stockfish project. I also hope that this change will improve our efficiency in using our generous CPU donors' machines, since it will remove one of the most common causes of buggy tests. Following helpful review and comments by Michael Stembera (@mstembera), we add a further clean-up by implementing OR for two Squares, to anticipate additional traps developers may encounter and handle them cleanly. Closes https://github.com/official-stockfish/Stockfish/pull/2387 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: SFisGOD
Date: Sat Nov 2 21:19:35 2019 +0100 Timestamp: 1572725975 Combo of Parameter Tweaks This patch is a combo of the following tweaks: Complexity parameters Knight PSQT Bishop PSQT King PSQT Piece Values Passed STC: LLR: 2.95 (-2.94,2.94) [-1.50,4.50] Total: 56527 W: 12326 L: 12052 D: 32149 Elo +1.68 http://tests.stockfishchess.org/tests/view/5dbbca3f0ebc5925b64ee6d6 Passed LTC: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 64010 W: 10549 L: 10199 D: 43262 Elo +1.90 http://tests.stockfishchess.org/tests/view/5dbc30dc0ebc5925b64eee0c Closes https://github.com/official-stockfish/Stockfish/pull/2390 Bench: 4312945 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: Thu Oct 31 17:47:23 2019 +0100 Timestamp: 1572540443 Simplify kingRing Simplify the king ring initialization and make it more regular, by just moving the king square off the edges and using PseudoAttacks by king from this new square. There is a small functional difference from the previous master, as the old master excludes the original ksq square while this patch always includes the nine squares block (after moving the king from the edges). Additionally, master does not adjust the kingRing down if we are on relative rank 8, while this patch treats all of the edges the same. STC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 13263 W: 2968 L: 2830 D: 7465 Elo +3.62 http://tests.stockfishchess.org/tests/view/5db872830ebc5902d1f388aa LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 72996 W: 11819 L: 11780 D: 49397 Elo +0.19 http://tests.stockfishchess.org/tests/view/5db899c20ebc5902d1f38b5e Closes https://github.com/official-stockfish/Stockfish/pull/2384 Bench: 4959244 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: Thu Oct 31 17:22:09 2019 +0100 Timestamp: 1572538929 Consolidate pawn_push and up This is a non-functional simplification. Pawn_push and Up are redundant. If we make up pawn_push, we can use it for all of the Up's and Down's. In this version, I've also left the Up and Down constants so that there is no worse readability. STC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 23878 W: 5202 L: 5085 D: 13591 Elo +1.70 http://tests.stockfishchess.org/tests/view/5db5569a0ebc5902d6b14de4 Closes https://github.com/official-stockfish/Stockfish/pull/2378 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: Stefan Geschwentner
Date: Thu Oct 31 17:05:29 2019 +0100 Timestamp: 1572537929 Tweak dynamic contempt (the birthday patch) Make dynamic contempt weight factor dependent on static contempt so that higher static contempt implies less dynamic contempt and vice versa. For default contempt 24 this is a non-functional change. But tests with contempt 0 shows an elo gain. Also today is my birthday so i have already give to myself a gift with this patch :-)! Further proceedings: in the past we checked for default contempt that it doesn't regress against contempt 0. Now that the later is stronger and the former is the same strength this should be rechecked. Perhaps the default contempt have to be lowered. It would be interesting to get some idea of the impact of this patch outside of the 0-24 contempt range. STC: (both with contempt=0) LLR: 2.95 (-2.94,2.94) [-1.50,4.50] Total: 21912 W: 3898 L: 3740 D: 14274 Elo +2.51 http://tests.stockfishchess.org/tests/view/5db74b6f0ebc5902d1f37405 LTC: (both with contempt=0) LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 27172 W: 3350 L: 3126 D: 20696 Elo +2.86 http://tests.stockfishchess.org/tests/view/5db760020ebc5902d1f375d0 Closes https://github.com/official-stockfish/Stockfish/pull/2382 No functional change (for current default contempt 24). 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: Sat Oct 26 01:10:55 2019 +0200 Timestamp: 1572045055 Refactor final stats updates. This PR refactors update_quiet_stats, update_capture_stats and search to more clearly reflect what is actually done. Effectively, all stat updates that need to be done after search is finished and a bestmove is found, are collected in a new function ```final_stats_update()```. This shortens our main search routine, and simplifies ```update_quiet_stats```. The latter function is now more easily reusable with fewer arguments, as the handling of ```quietsSearched``` is only needed in ```final_stats_update```. ```update_capture_stats```, which was only called once is now integrated in ```final_stats_update```, which allows for removing a branch and reusing some ```stat_bonus``` calls. The need for refactoring was also suggested by the fact that the comments of ```update_quiet_stats``` and ```update_capture_stats``` were incorrect (e.g. ```update_capture_stats``` was called, correctly, also when the bestmove was a quiet and not a capture). passed non-regression STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 75196 W: 16364 L: 16347 D: 42485 Elo +0.08 http://tests.stockfishchess.org/tests/view/5db004ec0ebc5902c06db9e1 The diff is most easily readable as ```git diff master --patience``` 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: Sat Oct 26 00:29:12 2019 +0200 Timestamp: 1572042552 Assorted trivial cleanups - Cleanups by Alain - Group king attacks and king defenses - Signature of futility_move_count() - Use is_discovery_check_on_king() - Simplify backward definition - Use static asserts in move generator - Factor a statement in move generator 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: Wed Oct 23 10:49:08 2019 +0200 Timestamp: 1571820548 Simplify reductions on singular extension Current master employs a scheme to adjust reductions on singular nodes that is somewhat controversial, see https://github.com/official-stockfish/Stockfish/pull/2167 This patch removes this use of a search result outside of [a,b], by observing that the main effect of this code is to adjust the reduction by an average of ~2 (1.7) rather than 1. Claims the first blue at STC and LTC: STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 30142 W: 6547 L: 6442 D: 17153 Elo +1.21 http://tests.stockfishchess.org/tests/view/5daf16c40ebc5902c06da566 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 45715 W: 7380 L: 7298 D: 31037 Elo +0.62 http://tests.stockfishchess.org/tests/view/5daf2f3c0ebc5902c06da6c7 Closes https://github.com/official-stockfish/Stockfish/pull/2367 Bench: 5115841 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: Tue Oct 22 00:02:46 2019 +0200 Timestamp: 1571695366 Avoid crashing on Log File opening Stockfish crashes immediately if users enter a wrong file name (or even an existing folder name) for debug log file. It may be hard for users to find out since it prints nothing. If they enter the string via a chess GUI, the chess GUI may remember and auto-send to Stockfish next time, makes Stockfish crashes all the time. Bug report by Nguyen Hong Pham in this issue: https://github.com/official-stockfish/Stockfish/issues/2365 This patch avoids the crash and instead prefers to exit gracefully with a error message on std:cerr, like we do with the fenFile for instance. Closes https://github.com/official-stockfish/Stockfish/pull/2366 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: Sun Oct 20 00:27:17 2019 +0200 Timestamp: 1571524037 Remove uithread With the current questions and issues around threading, I had a look at https://github.com/official-stockfish/Stockfish/issues/2299. It seems there was a problem with data races when requesting eval via UCI while a search was already running. To fix this an extra thread uithread was created, presumably to avoid an overlap with Threads.main() that was causing problems. Making this eval request seems to be outside the scope of UCI, and @vondele also reports that the data race is not even fixed reliably by this change. I suggest we simplify the threading here by removing this uithread and adding a comment signaling that user should not request eval when a search is already running. Closes https://github.com/official-stockfish/Stockfish/pull/2310 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: VoyagerOne
Date: Fri Oct 18 17:05:23 2019 +0200 Timestamp: 1571411123 Current capture for Counter-Move history Use current capture to index the CMH table instead of prior capture. STC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 61908 W: 13626 L: 13220 D: 35062 Elo +2.28 http://tests.stockfishchess.org/tests/view/5da8aa670ebc597ba8eda558 LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 49057 W: 8071 L: 7765 D: 33221 Elo +2.17 http://tests.stockfishchess.org/tests/view/5da8e99d0ebc597ba8eda9ca Closes https://github.com/official-stockfish/Stockfish/pull/2362 Bench: 4423737 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: Thu Oct 17 15:03:30 2019 +0200 Timestamp: 1571317410 Add four positions to bench The current bench is missing a position with high 50 moves rule counter, making most 'shuffle' tests based on 50mr > N seem non-functional. This patch adds one FEN with high 50mr counter to address this issue (taken from a recent tcec game). Four new FENs: - position with high 50mr counter - tactical position with many captures, checks, extensions, fails high/low - two losses by Stockfish in the S16 bonus games against Houdini See the pull request for nice comments by @Alayan-stk-2 about each position in bench: https://github.com/official-stockfish/Stockfish/pull/2338 Bench: 4590210 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: VoyagerOne
Date: Wed Oct 9 15:22:16 2019 +0900 Timestamp: 1570602136 Introduce separate counter-move tables for inCheck Enhance counter-move history table by adding a inCheck dimension. This doubles the size of the table but provides more accurate move ordering. STC: (yellow) LLR: -2.94 (-2.94,2.94) [0.50,4.50] Total: 36217 W: 7790 L: 7777 D: 20650 Elo +0.12 http://tests.stockfishchess.org/tests/view/5d9b9a290ebc5902b6d04fe0 LTC: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 36665 W: 6063 L: 5788 D: 24814 Elo +2.61 http://tests.stockfishchess.org/tests/view/5d9b9fcc0ebc5902b6d05985 Closes https://github.com/official-stockfish/Stockfish/pull/2353 Bench: 4053577 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: Wed Oct 9 14:17:52 2019 +0900 Timestamp: 1570598272 No reachable outpost bonus for bishops Previously, we used various control statements and ternary operators to divide Outpost into four bonuses, based on whether the outpost was for a knight or bishop, and whether it was currently an Outpost or merely a potential ("reachable") one in the future. Bishop outposts, however, have traditionally been worth far less Elo in testing. An attempt to remove them altogether passed STC, but failed LTC. Here we include a narrower simplification, removing the reachable Outpost bonus for bishops. This bonus was always suspect, given that its current implementation conflicts directly with BishopPawns. BishopPawns penalizes our bishops based on the number of friendly pawns on the same color of square, but by definition, Outposts must be pawn-protected! This PR helps to alleviate this conceptual contradiction without loss of Elo and with slightly simpler code. On a code level, this allows us to simplify a ternary operator into the previous "if" block and distribute a multiplication into an existing constant Score. On a conceptual level, we retire one of the four traditional Outpost bonuses. STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 22277 W: 4882 L: 4762 D: 12633 Elo +1.87 http://tests.stockfishchess.org/tests/view/5d9aeed60ebc5902b6cf9751 LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 51206 W: 8353 L: 8280 D: 34573 Elo +0.50 http://tests.stockfishchess.org/tests/view/5d9af1940ebc5902b6cf9cd5 Closes https://github.com/official-stockfish/Stockfish/pull/2352 Bench: 3941591 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: Alayan
Date: Mon Oct 7 22:30:04 2019 +0200 Timestamp: 1570480204 Adjust aspiration window with eval This patch changes the base aspiration window size depending on the absolute value of the previous iteration score, increasing it away from zero. This stems from the observation that the further away from zero, the more likely the evaluation is to change significantly with more depth. Conversely, a tighter aspiration window is more efficient when close to zero. A beneficial side-effect is that analysis of won positions without a quick mate is less prone to waste nodes in repeated fail-high that change the eval by tiny steps. STC: LLR: 2.96 (-2.94,2.94) [0.50,4.50] Total: 60102 W: 13327 L: 12868 D: 33907 Elo +2.65 http://tests.stockfishchess.org/tests/view/5d9a70d40ebc5902b6cf39ba LTC: LLR: 2.95 (-2.94,2.94) [0.00,3.50] Total: 155553 W: 25745 L: 25141 D: 104667 Elo +1.35 http://tests.stockfishchess.org/tests/view/5d9a7ca30ebc5902b6cf4028 Future work : the values used in this patch were only a reasonable guess. Further testing should unveil more optimal values. However, the aspiration window is rather tight with a minimum of 21 internal units, so discrete integers put a practical limitation to such tweaking. More exotic experiments around the aspiration window parameters could also be tried, but efficient conditions to adjust the base aspiration window size or allow it to not be centered on the current evaluation are not obvious. The aspiration window increases after a fail-high or a fail-low is another avenue to explore for potential enhancements. Bench: 4043748 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: SFisGOD
Date: Mon Oct 7 11:14:33 2019 +0200 Timestamp: 1570439673 Tweak kingFlankAttacks factor in kingDanger Increase kingFlankAttacks factor in kingDanger from 5/16 to 6/16. Failed STC: LLR: -2.96 (-2.94,2.94) [0.00,4.00] Total: 77947 W: 16989 L: 16848 D: 44110 Elo +0.63 http://tests.stockfishchess.org/tests/view/5d9ac0280ebc5902b6cf63cd Passed LTC 1: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 13443 W: 2231 L: 2037 D: 9175 Elo +5.01 http://tests.stockfishchess.org/tests/view/5d9ac88d0ebc5902b6cf6ffb Passed LTC 2: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 23340 W: 3842 L: 3617 D: 15881 Elo +3.35 http://tests.stockfishchess.org/tests/view/5d9acf7f0ebc5902b6cf7c27 Closes https://github.com/official-stockfish/Stockfish/pull/2349 Bench: 4042155 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: Mon Oct 7 00:50:54 2019 +0200 Timestamp: 1570402254 Adjust pawn span Run as a simplification a) insures that pawn attacks are always included in the pawn span (this "fixes" the case where some outpost or reachable outpost bonus were awarded on squares controlled by enemy pawns). b) compute the full span only if not "backward" or not "blocked". By looking at "blocked" instead of "opposed", we get a nice simpli- fication and the "new" outpost detection is almost identical, except a few borderline cases on rank 4. passed STC http://tests.stockfishchess.org/tests/view/5d9950730ebc5902b6cefb90 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 79113 W: 17168 L: 17159 D: 44786 Elo +0.04 passed LTC http://tests.stockfishchess.org/tests/view/5d99d14e0ebc5902b6cf0692 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 41286 W: 6819 L: 6731 D: 27736 Elo +0.74 See https://github.com/official-stockfish/Stockfish/pull/2348 bench: 3812891 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: Ondrej Mosnacek
Date: Sun Oct 6 23:05:30 2019 +0200 Timestamp: 1570395930 Make priorCapture a bool It is always used as a bool, so let's make it a bool straight away. We can always redefine it as a Piece in a later patch if we want to use the piece type or the piece color. 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: VoyagerOne
Date: Sun Oct 6 02:04:19 2019 +0200 Timestamp: 1570320259 Introduce separate counter-move tables for captures Enhance counter-move history table by adding a capture/no-capture dimension, depending wether the previous move was a quiet move or a capture. This doubles the size of the table but provides more accurate move ordering. STC: LLR: 2.95 (-2.94,2.94) [0.50,4.50] Total: 79702 W: 17720 L: 17164 D: 44818 Elo +2.42 http://tests.stockfishchess.org/tests/view/5d97945e0ebc590c21aa724b LTC: LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 29147 W: 4907 L: 4651 D: 19589 Elo +3.05 http://tests.stockfishchess.org/tests/view/5d97ccb90ebc590c21aa7bc0 Closes https://github.com/official-stockfish/Stockfish/pull/2344 Bench: 4131643 see source |