| 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 Aug 18 01:23:36 2018 +0200 Timestamp: 1534548216 Use an affine formula to mix stats and eval Follow-up for the previous patch: we use an affine formula to mix stats and evaluation in search. The idea is to give a bonus if the previous move of the opponent was historically bad, and a malus if the previous move of the opponent was historically good. More precisely, if x is the stat score of the previous move by the opponent, we implement the following formulas to tweak the evaluation at an internal node of the tree for our pruning decisions at this node: if x = 0, use v' = eval(P) if x > 0, use v' = eval(P) - 5 - x/1024 if x < 0, use v' = eval(P) + 5 - x/1024 For reference, the previous master had this simpler rule: if x > 0, use v' = eval(P) - 10 if x <= 0, use v' = eval(P) STC: LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 29322 W: 6359 L: 6088 D: 16875 Elo +3.21 http://tests.stockfishchess.org/tests/view/5b76a5980ebc5902bdba957f LTC: LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 30893 W: 5154 L: 4910 D: 20829 Elo +2.74 http://tests.stockfishchess.org/tests/view/5b76ca6d0ebc5902bdba9914 Closes https://github.com/official-stockfish/Stockfish/pull/1740 Bench: 4592766 |
| 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 Aug 17 11:40:29 2018 +0200 Timestamp: 1534498829 Mix search stats with evaluation Mix search stats with evaluation: if the opponent's move has a good historyStat, then decrease the evaluation of the internal node a bit for the pruning decisions during search. STC; LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 72083 W: 15683 L: 15203 D: 41197 Elo +2.31 http://tests.stockfishchess.org/tests/view/5b74c3ea0ebc5902bdba7d41 LTC: LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 29104 W: 4867 L: 4630 D: 19607 Elo +2.83 http://tests.stockfishchess.org/tests/view/5b7565000ebc5902bdba851b Closes https://github.com/official-stockfish/Stockfish/pull/1738 Bench: 4514101 ----------- How to continue from there? • the use of the previous stat score can probably be simplified in lines 587 and 716 • we could try to use a continuous bonus based on the previous stat score, instead of just a fixed offset of -10 when the opponent previous move was good. ---------- Comments by Stefan Geschwentner: Interesting idea. Because only the eval in search is tweak this should only influence the eval and static eval used at inner nodes, and not on the return search value (which comes in the end from quiescence search), except through saving in TT followed by a TT cutoff. So essentialy this effects diverse pruning/reduction parts -- eval and static eval are lowered for good opponent moves: • tt cutoff (ttValue) • improving (static eval) • more razoring (eval) • less futility pruning (eval) • less null move pruning (eval + static eval) (but with little more depth) • more probcut (static eval) • more move futility pruning (static eval) |
| 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: Fri Aug 17 10:21:20 2018 +0200 Timestamp: 1534494080 Simplify king file dependancy in evaluate_shelter() Remove the special value we used for the file of the king in the evaluate_shelter() function, and compensate by tweaking some of the ShelterStrength[] array values. STC LLR: 2.94 (-2.94,2.94) [-3.00,1.00] Total: 17069 W: 3782 L: 3652 D: 9635 Elo +2.65 http://tests.stockfishchess.org/tests/view/5b75eb0d0ebc5902bdba8f3d LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 42639 W: 6973 L: 6887 D: 28779 Elo +0.70 http://tests.stockfishchess.org/tests/view/5b75fd7f0ebc5902bdba906b Closes https://github.com/official-stockfish/Stockfish/pull/1739 Bench: 4639508 |
| 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 Aug 14 10:12:31 2018 +0200 Timestamp: 1534234351 Double weight of capture history We double in this patch the weight of the capture history table in the local scoring of captures for move ordering. The capture history table is indexed by the triplet (capturing piece, capture square, captured piece) and gets information like "it seems to have been historically good in that part of the search tree to capture a pawn with a rook on g3, even if it seems to lose material", and affect the normaly pure « Most Valuable Victim » ordering of captures. Finished yellow at STC after 228842 games (posting a +1.36 Elo gain): LLR: -2.95 (-2.94,2.94) [0.00,4.00] Total: 228842 W: 50894 L: 50152 D: 127796 Elo +1.13 http://tests.stockfishchess.org/tests/view/5b714bb00ebc5902bdba332d Passed LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 43251 W: 7425 L: 7131 D: 28695 Elo +2.36 http://tests.stockfishchess.org/tests/view/5b71c7d40ebc5902bdba3e51 Thanks to user Vizvezdenec for running the LTC test. Closes https://github.com/official-stockfish/Stockfish/pull/1736 Bench: 4272361 |
| 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 Aug 14 08:36:27 2018 +0200 Timestamp: 1534228587 Remove pawncount array in imbalance This is a natural follow up to last commit where values on the QuadraticOurs diagonal and some piece value deltas were changed. @Stefano80 tried to simplify the newly introduced pawncount array using QuadraticOurs[1][1] =52 and a -30 adjustment on pawn values His STC [-3,1] was green http://tests.stockfishchess.org/tests/view/5b707f5b0ebc5902bdba2745 but not his LTC[-3,1] http://tests.stockfishchess.org/tests/view/5b7095700ebc5902bdba2a49 So I started a 80000 30+0.3 SPSA on the QuadraticOurs diagonal and on the piece values using @Stefano80 start values. SPSA gave the new values QuadraticOurs[1][1] =38 and a -33 on pawn values (the other changes on QuadraticOurs were kept, but were not ignificant according to this test http://tests.stockfishchess.org/tests/view/5b710ccb0ebc5902bdba2f27) STC http://tests.stockfishchess.org/tests/view/5b710b220ebc5902bdba2f19 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 50902 W: 11214 L: 11150 D: 28538 Elo +0.44 LTC http://tests.stockfishchess.org/tests/view/5b7124ef0ebc5902bdba3106 LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 34271 W: 5852 L: 5753 D: 22666 Elo +1.00 Closes https://github.com/official-stockfish/Stockfish/pull/1735 bench: 4738555 |
| 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: GuardianRM
Date: Sun Aug 12 18:40:11 2018 +0200 Timestamp: 1534092011 Non-linear bonus for pawn count This patch introduces a non-linear bonus for pawns, along with some (linear) corrections for the other pieces types. The original values were obtained by a massive non-linear tuning of both pawns and other pieces by GuardianRM, while Alain Savard and Chris Cain later simplified the patch by observing that, apart from the pawn case, the tuned corrections were in fact almost affine and could be incorporated in our current code base via the piece values in types.h (offset) and the diagonal of the quadratic matrix (slope). See discussion in PR#1725 : https://github.com/official-stockfish/Stockfish/pull/1725 STC: LLR: 2.97 (-2.94,2.94) [0.00,5.00] Total: 42948 W: 9662 L: 9317 D: 23969 Elo +2.79 http://tests.stockfishchess.org/tests/view/5b6ff6e60ebc5902bdba1d87 LTC: LLR: 2.97 (-2.94,2.94) [0.00,5.00] Total: 19683 W: 3409 L: 3206 D: 13068 Elo +3.58 http://tests.stockfishchess.org/tests/view/5b702dbd0ebc5902bdba216b How to continue from there? - Maybe the non-linearity for the pawn value could be somewhat tempered again and a simpler linear correction for pawns would work? Closes https://github.com/official-stockfish/Stockfish/pull/1734 Bench: 4681496 |
| 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: Stefano Cardanobile
Date: Sun Aug 12 10:09:30 2018 +0200 Timestamp: 1534061370 Combo of several promising parameter tweaks Combo of several tuning patches which finished yellow at LTC. [STC](http://tests.stockfishchess.org/tests/view/5b6ead340ebc5902bdba14ce) LR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 10668 W: 2445 L: 2239 D: 5984 Elo +6.71 Elo: 6.25 [1.76,10.69] (95%) [LTC](http://tests.stockfishchess.org/tests/view/5b6eb50e0ebc5902bdba151f) LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 23761 W: 4155 L: 3923 D: 15683 Elo +3.39 Elo: 3.02 [0.29,5.67] (95%) Original patches: - [Piece values](http://tests.stockfishchess.org/tests/view/5b6d2cc00ebc5902bdba02d5) by Stefano Cardanobile - [Stat bonus](http://tests.stockfishchess.org/tests/view/5b6adbc90ebc5902bdb9da73) by Stefan Geschwentner - [Rook on pawn](http://tests.stockfishchess.org/tests/view/5b62a95b0ebc5902bdb961c0) by Mark Tenzer - [Hanging bonus](http://tests.stockfishchess.org/tests/view/5b5d2fa00ebc5902bdb90855) by Ivan Ilvec - [ss tweak](http://tests.stockfishchess.org/tests/view/5b58b7240ebc5902bdb89025) by miguel-l Bench: 4694813 |
| 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: Jerry Donald Watson
Date: Sun Aug 12 09:54:16 2018 +0200 Timestamp: 1534060456 Simple razoring: depth 1 only, no distinction between PV / NonPV We simplify the razoring logic by applying it to all nodes at depth 1 only. An added advantage is that only one razor margin is needed now, and we treat PV and Non-PV nodes in the same manner. How to continue? - There may be some conditions in which depth 2 razoring is beneficial. - We can see whether the razor margin can be tuned, perhaps even with a different value for PV nodes. - Perhaps we can unify the treatment of PV and Non-PV nodes in other parts of the search as well. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 5474 W: 1281 L: 1127 D: 3066 Elo +9.78 http://tests.stockfishchess.org/tests/view/5b6de3b20ebc5902bdba0d1e LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 62670 W: 10749 L: 10697 D: 41224 Elo +0.29 http://tests.stockfishchess.org/tests/view/5b6dee340ebc5902bdba0eb0 In addition, we ran a fixed LTC test against a similar patch which also passed SPRT [-3, 1]: ELO: 0.23 +-2.1 (95%) LOS: 58.6% Total: 36412 W: 6168 L: 6144 D: 24100 Elo +0.23 http://tests.stockfishchess.org/tests/view/5b6e83940ebc5902bdba1485 We are opting for this patch as the more logical and simple of the two, and it appears to be no less strong. Thanks in particular to @DU-jdto for input into this patch. Bench: 4476945 |
| 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: Miguel Lahoz
Date: Fri Aug 10 06:16:29 2018 +0200 Timestamp: 1533874589 Remove Condition For Passed Pawns Currently, we do not consider pawns passed if there is another pawn of the same color in front of them. It appears that this condition is not necessary. The idea is that the doubled pawns are likely to be weak and one of them will be likely captured anyway. On the other hand, if we do somehow manage to promote a pawn, then the pawn behind it becomes passed as well. In any case, the end result is we end up with an extra potentially passed pawn. The current evaluation for passed pawns already handles this case by also scaling down this effect. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 28291 W: 6287 L: 6178 D: 15826 Elo +1.34 http://tests.stockfishchess.org/tests/view/5b6c4b960ebc5902bdb9f256 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 30717 W: 5256 L: 5151 D: 20310 Elo +1.19 http://tests.stockfishchess.org/tests/view/5b6c82980ebc5902bdb9f863 Bench: 4938285 |
| 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 Aug 9 14:45:35 2018 +0200 Timestamp: 1533818735 LMR simplification Unify the "quiet" and "non-quiet" reduction rules for use at any kind of moves. The idea behind it was that both rules reduce at similiar cases in master: one directly for late previous moves and the other indirectly by using a bad stat score which is used for most move sorting and so approximates the late move condition. For captures/promotions the old rule was triggered in 25% but the new rule only for 3% of all cases (so now more reductions are done, whereas for quiet moves reductions keep the same level). STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 162327 W: 35976 L: 36134 D: 90217 Elo -0.34 http://tests.stockfishchess.org/tests/view/5b6a9a430ebc5902bdb9d5c1 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 29570 W: 5083 L: 4976 D: 19511 Elo +1.26 http://tests.stockfishchess.org/tests/view/5b6bc5d00ebc5902bdb9e9d6 Bench: 4526980 |
| 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: Stefano Cardanobile
Date: Wed Aug 8 17:58:41 2018 +0200 Timestamp: 1533743921 First check threshold in space evaluation Currently, we first calculate some bitboards at the top of Evaluation::space() and then check whether we actually need them. Invert the ordering. Of course this does not make a difference in current master because the constexpr bitboard calculations are in fact done at compile time by any decent compiler, but I find my version a bit healthier since it will always meet or exceed current implementation even if we eventually change the spaceMask to something not contsexpr. No functional change. |
| 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: FauziAkram
Date: Wed Aug 8 17:49:16 2018 +0200 Timestamp: 1533743356 King Psqt Tuning After a session of tuning for King Psqt I got some new values, which was later tweaked manually by me Fauzi, to result in an Elo-gain patch which seems to scale pretty well: STC: LLR: -2.96 (-2.94,2.94) [0.00,4.00] Total: 100653 W: 22550 L: 22314 D: 55789 Elo +0.81 LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 147079 W: 25584 L: 24947 D: 96548 Elo +1.50 Bench: 4669050 |
| 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: Stefano Cardanobile
Date: Wed Aug 8 17:34:12 2018 +0200 Timestamp: 1533742452 Introduce voting system for best move selection Introduce voting system for best move selction in multi-threads mode. Joint work with Stefan Geschwentner, based on ideas introduced by Michael Stembera. Moves are upvoted by every thread using the margin to the minimum score across threads and the completed depth. First thread voting for the winner move is selected as best thread. Passed STC, LTC. A further LTC test with only 4 threads failed with positive score. A LTC with 31 threads was stopped with LLR 0.77 after 25k games to avoid use of excessive resources (equivalent to 1.5M STC games). Similar ideas were proposed by Michael Stembera 2 years ago #507, #508. This implementation seems simpler and more understandable, the results slightly more promising. Further possible work: 1) Tweak of the formula using for assigning votes. 2) Use a different baseline for the score dependent part: maximum score or winning probability could make more sense. 3) Assign votes in `Thread::Search` as iterations are completed and use voting results to stop search. 4) Select best thread as the threads voting for best move with the highest completed depth or, alternatively, vote on PV moves. Link to SPRT tests [stopped LTC, 31 threads 20+0.02](http://tests.stockfishchess.org/tests/view/5b61dc090ebc5902bdb95192) LLR: 0.77 (-2.94,2.94) [0.00,5.00] Total: 25602 W: 3977 L: 3850 D: 17775 Elo +1.72 Elo: 1.70 [-0.68,4.07] (95%) [passed LTC, 8 threads 20+0.02](http://tests.stockfishchess.org/tests/view/5b5df5180ebc5902bdb9162d) LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 44478 W: 7602 L: 7300 D: 29576 Elo +2.36 Elo: 1.92 [-0.29,3.94] (95%) [failed LTC, 4 threads 20+0.02](http://tests.stockfishchess.org/tests/view/5b5f39ef0ebc5902bdb92792) LLR: -2.94 (-2.94,2.94) [0.00,5.00] Total: 29922 W: 5286 L: 5285 D: 19351 Elo +0.01 Elo: 0.48 [-1.98,3.10] (95%) [passed STC, 4 threads 5+0.05](http://tests.stockfishchess.org/tests/view/5b5dbf0f0ebc5902bdb9131c) LLR: 2.97 (-2.94,2.94) [0.00,5.00] Total: 9108 W: 2033 L: 1858 D: 5217 Elo +6.68 Elo: 6.11 [1.26,10.89] (95%) No functional change (in simple threat mode) |
| 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: Marco Costalba
Date: Wed Aug 1 12:40:12 2018 +0200 Timestamp: 1533120012 Improve Stats definition Use operator const T&() instead of operator T() to avoid possible costly hidden copies of non-scalar nested types. Currently StatsEntry has a single member T, so assuming sizeof(StatsEntry) == sizeof(T) it happens to work, but it's better to use the size of the proper entry type in std::fill. Note that current code works because std::array items are ensured to be allocated in contiguous memory and there is no padding among nested arrays. The latter condition does not seem to be strictly enforced by the standard, so be careful here. Finally use address-of operator instead of get() to fully hide the wrapper class StatsEntry at calling sites. For completness add the arrow operator too and simplify the C++ code a bit more. Same binary code as previous master under the Clang compiler. No functional change. |
| 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: Marco Costalba
Date: Tue Jul 31 11:56:10 2018 +0200 Timestamp: 1533030970 Small tweaks to recent code changes As a note, current 2 LMR conditions on stat score could be simplified in a single line: r -= ((ss->statScore >= 0) - ((ss-1)->statScore >= 0)) * ONE_PLY; We keep them splitted in 2 "if" statements because are easier to (immediately) read. No functional change. |
| 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: Tue Jul 31 11:24:28 2018 +0200 Timestamp: 1533029068 7-pieces Syzygy tablebase support This is the first patch teaching Stockfish how to use the 7-pieces Syzygy tablebase currently calculated by Bujun Guo (@noobpwnftw) and Ronald de Man (@syzygy1). The 7-pieces database are so big that they required a change in the internal format of the files (technically, some DTZ values are 16 bits long, so this had to be stored as wide integers in the Huffman tree). Here are the estimated file size for the 7-pieces Syzygy files, compared to the 151G of the 6-pieces Syzygy: ``` 7.1T ./7men_testing/4v3_pawnful (ongoing, 120 of 325 sets remaining) 2.4T ./7men_testing/4v3_pawnless 2.3T ./7men_testing/5v2_pawnful 660G ./7men_testing/5v2_pawnless 117G ./7men_testing/6v1_pawnful 87G ./7men_testing/6v1_pawnless ``` Some pointers to download or recalculate the tables: Location of original files, by Bujun Guo: ftp://ftp.chessdb.cn/pub/syzygy/ Mirrors: http://tablebase.sesse.net/ (partial) http://tablebase.lichess.ovh/tables/standard/7/ Generator code: https://github.com/syzygy1/tb/ Closes https://github.com/official-stockfish/Stockfish/pull/1707 Bench: 5591925 (No functional change if SyzygyTB is not used) ---------------------- Comment by Leonardo Ljubičić (@DragonMist) This is an amazing achievement, generating and being able to use 7 men syzygy on the fly. Thank you for your efforts @noobpwnftw !! Looking forward how this will work in real life, and expecting some trade off between gaining perfect play and slow disc Access, but once the disc speed and space is not a problem, I expect 7 men to yield something like 30 elo at least. ----------------------- Comment by Michael Byrne (@MichaelB7) This definitely has a bright future. I turned off the 50 move rule (ala ICCF new rules) for the following position: `[d]8/8/1b6/8/4N2r/1k6/7B/R1K5 w - - 0 1` This position is a 451 ply win for white (sans the 50 move rule, this position was identified by the generator as the longest cursed win for white in KRBN v KRB). Now Stockfish finds it instantly (as it should), nice work 👊👍 . ``` dep score nodes time 7 +132.79 4339 0:00.00 Rb1+ Kc4 Nd6+ Kc5 Bg1+ Kxd6 Rxb6+ Kc7 Be3 Rh2 Bd4 6 +132.79 1652 0:00.00 Rb1+ Kc4 Nd2+ Kd5 Rxb6 Rxh2 Nf3 Rf2 5 +132.79 589 0:00.00 Rb1+ Kc4 Rxb6 Rxh2 Nf6 Rh1+ Kb2 4 +132.79 308 0:00.00 Rb1+ Kc4 Nd6+ Kc3 Rxb6 Rxh2 3 +132.79 88 0:00.00 Rb1+ Ka4 Nc3+ Ka5 Ra1+ Kb4 Ra4+ Kxc3 Rxh4 2 +132.79 54 0:00.00 Rb1+ Ka4 Nc3+ Ka5 Ra1+ Kb4 1 +132.7 ``` |
| 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 Jul 30 08:26:48 2018 +0200 Timestamp: 1532932008 Introduce tropism measure in king danger This patch adds the tropism measure as a new term in the king danger variable. Since we then trasform this variable as a Score via a quadratic formula, the main effect of the patch is the positive correlation of the tropism measure with some checks and pins information already present in the king danger code. STC: LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 6805 W: 1597 L: 1431 D: 3777 Elo +8.48 http://tests.stockfishchess.org/tests/view/5b5df8d10ebc5902bdb91699 LTC: LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 32872 W: 5782 L: 5523 D: 21567 Elo +2.74 http://tests.stockfishchess.org/tests/view/5b5e08d80ebc5902bdb917ee How to continue from there? • it may be possible to use CloseEnemies=S(7,0) • we may want to try incorporating other strategic features in the quadratic king danger. Closes https://github.com/official-stockfish/Stockfish/pull/1717 Bench: 5591925 |
| 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: Miguel Lahoz
Date: Sat Jul 28 07:34:37 2018 +0200 Timestamp: 1532756077 Increase the mg->eg gradient for the PawnlessFlank malus Just a change of value to S(19, 84). Also somewhat of a follow up to the recent tweak in definition of KingFlank. I tried a lot of other values before this, increasing and decreasing but with little success, and before giving up I wanted to try tweaking the middlegame and endgame values in the opposite directions. I guess this is somewhat lucky. STC: LLR: 2.94 (-2.94,2.94) [0.00,4.00] Total: 67685 W: 15399 L: 14963 D: 37323 Elo +2.24 http://tests.stockfishchess.org/tests/view/5b5b5ae80ebc5902bdb8e4f8 LTC: (Also thanks to Stephane Nicolet) LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 54635 W: 9505 L: 9172 D: 35958 Elo +2.12 http://tests.stockfishchess.org/tests/view/5b5b78f20ebc5902bdb8ece5 Closes https://github.com/official-stockfish/Stockfish/pull/1714 Bench: 4883742 |
| 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 Jul 27 16:23:45 2018 +0200 Timestamp: 1532701425 Simplify cmh pruning Simplify cmh pruning by removing PvNode exception STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 9935 W: 2330 L: 2184 D: 5421 Elo +5.11 http://tests.stockfishchess.org/tests/view/5b587dc00ebc5902bdb88424 LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 20635 W: 3585 L: 3464 D: 13586 Elo +2.04 http://tests.stockfishchess.org/tests/view/5b58910a0ebc5902bdb885b9 Closes https://github.com/official-stockfish/Stockfish/pull/1711 Bench: 4905530 |
| 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: Fri Jul 27 15:46:13 2018 +0200 Timestamp: 1532699173 Fix a compilation error for MSVC The previous commit wouldn't compile on the Microsoft Virtual Studio C++ compiler. So use a more compatible style for the same idea (which we already use in numerous places of evaluate.cpp, for instance in line 563). Under the Clang compiler, both versions generate exactly the same machine code (same md5 signatures for the two binaries). No functional change. |
| 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: Fri Jul 27 15:23:57 2018 +0200 Timestamp: 1532697837 Remove a popcount for HinderPassedPawn Remove a popcount for HinderPassedPawn, and compensate by doubling the bonus from S(4,0) to to S(8,0). Maybe it was pure luck, but we got the idea of this Elo gaining patch by seing the simplification attempt by Mike Whiteley in pull request #1703. This suggests that whenever we have a passed evaluation simplification, we should consider the possibility that the master bonus has become slightly out of tune with time, and we should try a few Elo gaining [0..4] tests by hand-tuning the master bonus. STC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 19136 W: 4388 L: 4147 D: 10601 Elo +4.38 http://tests.stockfishchess.org/tests/view/5b59be6f0ebc5902bdb8ac06 LTC: LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 99382 W: 17324 L: 16843 D: 65215 Elo +1.68 http://tests.stockfishchess.org/tests/view/5b59d2410ebc5902bdb8afa8 Closes https://github.com/official-stockfish/Stockfish/pull/1710 Bench: 4688817 |
| 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: Miguel Lahoz
Date: Fri Jul 27 10:38:20 2018 +0200 Timestamp: 1532680700 Tweak KingFlank when king is on edge files This tweak excludes files D and E from the KingFlank bitboard when our king is on the A or H files respectively. As far as I can tell, this affects two things: the calculation for CloseEnemies and PawnlessFlank. Aside from filtering out slightly less relevant attacks in the flank, I suspect this helps with king prophylaxis, avoiding attacks and moving towards the center when the pawns start to come off. STC LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 56755 W: 12881 L: 12489 D: 31385 Elo +2.40 http://tests.stockfishchess.org/tests/view/5b58a94c0ebc5902bdb88c72 LTC LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 130205 W: 22536 L: 21957 D: 85712 Elo +1.54 http://tests.stockfishchess.org/tests/view/5b58b7580ebc5902bdb89029 How to continue: Tweaking the two bonuses mentioned might give some gain, although as far as I can tell, CloseEnemies is very sensitive to even small changes. Closes https://github.com/official-stockfish/Stockfish/pull/1705 Bench: 5026009 |
| 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: Jekaa
Date: Fri Jul 27 10:30:53 2018 +0200 Timestamp: 1532680253 Small reformat in evaluate threats (non functional) When evaluating threat by safe pawn and pawn push the same expression is used. STC LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 19444 W: 4540 L: 4309 D: 10595 Elo +4.13 http://tests.stockfishchess.org/tests/view/5b5a6e150ebc5902bdb8c5c0 Closes https://github.com/official-stockfish/Stockfish/pull/1709 No functional change. -------------------- Comments by Stéphane Nicolet: I don't measure any speed-up on my system, with two parallel benches at depth 22: Total time (ms) : 74989 Nodes searched : 144830258 Nodes/second : 1931353 master Total time (ms) : 75341 Nodes searched : 144830258 Nodes/second : 1922329 testedpatch And anyway, like Stefan Geschwentner, I don't think that a 0.3% speed-up would be enough to pass a [0..5] LTC test -- as a first approximation, we have this rule of thumb that 1% speed-up gives about 1 Elo point. However, considering the facts that the reformatting by itself is interesting, that this is your first green test and that you played by the rules by running the SPRT[0..5] test before opening the pull request, I will commit the change. I will only take the liberty to change the occurrences of safe in lines 590 and 591 to b, to make the code more similar to lines 584 and 585. So approved, and congrats :-) |
| 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: ianfab
Date: Fri Jul 27 10:16:33 2018 +0200 Timestamp: 1532679393 Fix condition for error message of signature script Use obtained bench instead of reference bench when checking for crash. No functional change. |
| 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 Jul 26 09:34:22 2018 +0200 Timestamp: 1532590462 Remove condition for pawn threats It appears as though removing squares that are already attacked by our pawns can be removed. STC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 51242 W: 11503 L: 11440 D: 28299 Elo +0.43 http://tests.stockfishchess.org/tests/view/5b58b5a40ebc5902bdb88f52 LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 35246 W: 6063 L: 5966 D: 23217 Elo +0.96 http://tests.stockfishchess.org/tests/view/5b58f8e20ebc5902bdb8959b How to continue after this patch: there is now a slight semantic overlap between the ThreatByPawnPush and the ThreatBySafePawn bonuses, so hand-tuning either of these, or both at the same time, is natural. Closes https://github.com/official-stockfish/Stockfish/pull/1702 Bench 4734881 |