| 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: Sat Jul 21 07:05:50 2018 +0200 Timestamp: 1532149550 Simplify the "overload" condition This is a follow-up of the previous pull request (#1686) by Miguel. We simplify the "Overload" bonus condition by re-using the "weak" variable, which captures well the essence of the overload condition. This may also be a small speed optimization because the weak variable is in a register at this point of the code. http://tests.stockfishchess.org/tests/view/5b527b440ebc5902bdb7f7db LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 10925 W: 2517 L: 2374 D: 6034 Elo +4.55 http://tests.stockfishchess.org/tests/view/5b527f930ebc5902bdb7f883 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 15569 W: 2697 L: 2568 D: 10304 Elo +2.88 Closes https://github.com/official-stockfish/Stockfish/pull/1687 Bench: 5010472 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: Miguel Lahoz
Date: Sat Jul 21 06:56:48 2018 +0200 Timestamp: 1532149008 Remove connectivity. There seems to be some strange interaction between Overload and Connectivity. Overload encourages us to not have too many defended and attacked pieces, as this may expose us to various tactics. This feels somewhat like it is in conflict with Connectivity, where pieces are defended preemptively. Here I take the "pick one or the other" approach and just remove connectivity, while strengthening the effect of Overload to compensate. The reasoning is that if we defend our pieces preemptively, then it does get attacked, we want to do something about it so we don't get penalized by Overload. On the other hand, if it doesn't get attacked, then there's no need to defend it. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 27734 W: 6174 L: 6064 D: 15496 Elo +1.38 http://tests.stockfishchess.org/tests/view/5b5073bd0ebc5902bdb7ba5c LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 51606 W: 8897 L: 8827 D: 33882 Elo +0.47 http://tests.stockfishchess.org/tests/view/5b50aa900ebc5902bdb7bf29 Bench: 4658006 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 Jul 19 18:27:20 2018 +0200 Timestamp: 1532017640 Better check evasion move sorting Use in addition the counter move history table for sorting quiet check evasion moves in main and quiecence search. Also rename "contHistory" to "continuationHistory" while there. STC: LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 73284 W: 16433 L: 15938 D: 40913 Elo +2.35 http://tests.stockfishchess.org/tests/view/5b4f526e0ebc5902bdb7a401 LTC: LLR: 2.96 (-2.94,2.94) [0.00,5.00] Total: 12135 W: 2171 L: 1997 D: 7967 Elo +4.98 http://tests.stockfishchess.org/tests/view/5b4fc0ef0ebc5902bdb7ae0e Closes https://github.com/official-stockfish/Stockfish/pull/1685 Bench 4817583 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: Miguel Lahoz
Date: Wed Jul 18 08:44:45 2018 +0200 Timestamp: 1531896285 Use single value for KingProtector. After some recent big tuning session, the values for King Protector were simplified to only be used on minor pieces. This patch tries to further simplify by just using a single value, since current S(6,5) and S(5,6) are close to each other. The value S(6,6) ended up passing, although S(5,5) was also tried and failed STC. STC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 14261 W: 3288 L: 3151 D: 7822 Elo +3.34 http://tests.stockfishchess.org/tests/view/5b4ccdf50ebc5902bdb77f65 LTC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 19606 W: 3396 L: 3273 D: 12937 Elo +2.18 http://tests.stockfishchess.org/tests/view/5b4ce4280ebc5902bdb7803b Bench: 5448998 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: ElbertoOne
Date: Wed Jul 18 08:37:13 2018 +0200 Timestamp: 1531895833 Simplify Overload condition Extend the bonus for Overload to cases where our side has more than one attacker to a non pawn piece. Based on an idea by Bryan in the forum. For instance, now black gets the overload bonus in this position: 8/5R1k/6pb/p6p/P1N4P/1Pp5/2K3P1/2N4r b - - 6 46 because two black pieces are attacking the knight on c1 that is defended only by the king. STC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 57446 W: 12762 L: 12711 D: 31973 Elo +0.31 http://tests.stockfishchess.org/tests/view/5b4ca9970ebc5902bdb77a88 LTC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 42113 W: 7295 L: 7209 D: 27609 Elo +0.71 http://tests.stockfishchess.org/tests/view/5b4ccea00ebc5902bdb77f69 Bench: 4667263 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: DU-jdto
Date: Wed Jul 18 08:26:33 2018 +0200 Timestamp: 1531895193 Minor code style tweaks 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: ianfab
Date: Wed Jul 18 08:25:08 2018 +0200 Timestamp: 1531895108 Minor whitespace formatting changes 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: Gian-Carlo Pascutto
Date: Wed Jul 18 08:14:57 2018 +0200 Timestamp: 1531894497 Allow Position::init() to be called multiple times. For the rationale to allow this, see commit a66c73deef420104e74b6645ee60e20b37fd8549 This was broken when cuckoo hashing was added, and subtly broke (for example) lichess' Android application, thus illustrating the original judgement was sound. 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: protonspring
Date: Sat Jul 14 08:27:33 2018 +0200 Timestamp: 1531549653 Remove rank limitation for MinorBehindPawn This is a functional simplification. It seems like the rank restriction for MinorBehindPawn can be removed. STC LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 61195 W: 13404 L: 13360 D: 34431 Elo +0.25 http://tests.stockfishchess.org/tests/view/5b47e6f00ebc5978f4be3fc0 LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 31701 W: 5367 L: 5264 D: 21070 Elo +1.13 http://tests.stockfishchess.org/tests/view/5b48a2cb0ebc5978f4be4769 Bench: 4938702 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: candirufish
Date: Sat Jul 14 08:13:15 2018 +0200 Timestamp: 1531548795 Tuned Values after 2 million spsa games Various king and pawn eval values tuned after 2 million games. Rounding slightly adjusted. LTC: http://tests.stockfishchess.org/tests/view/5b477a260ebc5978f4be3ed4 LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 32783 W: 5852 L: 5588 D: 21343 Elo +2.80 STC: http://tests.stockfishchess.org/tests/view/5b472d420ebc5978f4be3e4d LLR: 3.23 (-2.94,2.94) [0.00,4.00] Total: 44380 W: 10201 L: 9841 D: 24338 Elo +2.82 I think I reached the limit of the fishtest framework. It frequently crashed at 2 million games already. The small values also moved a lot throughout the entire tuning session though with smaller margin. The passed danger and close enemies values seems the most sensitive (changing close enemies alone to 6 failed before but now it passes), whether or not they are close to optimal I don't know, but it seems some parameters are also correlated to others. Closes https://github.com/official-stockfish/Stockfish/pull/1670 bench: 5103722 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 Jul 7 10:42:06 2018 +0200 Timestamp: 1530952926 Remove offset in thread redistribution scheme. doesn't have a benefit. passed STC (8 threads): LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 19574 W: 4028 L: 3904 D: 11642 Elo +2.20 http://tests.stockfishchess.org/tests/view/5b3e48950ebc5902b9fff080 passed LTC (8 threads): LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 21293 W: 3626 L: 3506 D: 14161 Elo +1.96 http://tests.stockfishchess.org/tests/view/5b3eefd60ebc5902b9fffa81 Closes https://github.com/official-stockfish/Stockfish/pull/1667 No functional change single threaded. 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 Jul 6 01:34:01 2018 +0200 Timestamp: 1530833641 Simplify ThreatByKing to be a single Score. In the current master, ThreatByKing is an array of two Scores, one for when we have a single attack and one for when we have many. The latter case is very rarely called during bench and was recently given a strange negative value during a tuning run, as pointed out by @candirufish on commit efd4ca2. Here, we simplify away this second case entirely, and increase the remaining ThreatByKing to compensate. Although I derived the parameter tweak independently, with the goal of preserving the same average bonus, I later noticed that a very similar Score had already been derived by an ongoing SPSA tuning session. I therefore recognize @candirufish for first discovering these values. I would also like to thank @Rocky640 for valuable feedback that pointed me in the direction of ThreatByKing. STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 7677 W: 1772 L: 1623 D: 4282 Elo +6.74 http://tests.stockfishchess.org/tests/view/5b3db0320ebc5902b9ffe97a LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 108031 W: 18329 L: 18350 D: 71352 Elo -0.07 http://tests.stockfishchess.org/tests/view/5b3dbf4b0ebc5902b9ffe9db Closes https://github.com/official-stockfish/Stockfish/pull/1666 Bench: 4678861 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 Jul 4 01:12:16 2018 +0200 Timestamp: 1530659536 Capture Stat Tweak Penalize capture moves that fail to create a cutoff even at quiet move cutoff. STC: LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 19004 W: 4284 L: 4059 D: 10661 Elo +4.11 http://tests.stockfishchess.org/tests/view/5b3a7d4d0ebc5902b9ffb6ea LTC: LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 23100 W: 3981 L: 3765 D: 15354 Elo +3.25 http://tests.stockfishchess.org/tests/view/5b3aa4550ebc5902b9ffb8cf Closes https://github.com/official-stockfish/Stockfish/pull/1664 Bench: 5232010 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 Jul 4 00:59:15 2018 +0200 Timestamp: 1530658755 Simplify saving a TT entry. Avoid passing TT.generation() to TTEntry::save() at every call, moving the implementation of TTEntry::save from tt.h to tt.cpp. tested for no regression: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 53787 W: 11948 L: 11890 D: 29949 Elo +0.37 http://tests.stockfishchess.org/tests/view/5b2ff37f0ebc5902b2e582fe Closes https://github.com/official-stockfish/Stockfish/pull/1662 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 Jul 4 00:51:10 2018 +0200 Timestamp: 1530658270 Reduce scope of variables Small cleanup TranspositionTable:clear(). Closes https://github.com/official-stockfish/Stockfish/pull/1659 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: Ondrej Mosnáček
Date: Wed Jun 27 11:42:25 2018 +0200 Timestamp: 1530092545 Move PSQ score to Position This patch simplifies Position::do_move() by moving the PSQ score from StateInfo to Position and updating it inside the put/remove/move_piece functions. The downside is that there is now slightly more computation done in Position::undo_move(), but the fishtest results are Elo neutral. Passed STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 78820 W: 15775 L: 15760 D: 47285 Elo +0.07 http://tests.stockfishchess.org/tests/view/5b1cd1d00ebc5902ab9c64ab Passed LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 32966 W: 5716 L: 5615 D: 21635 Elo +1.06 http://tests.stockfishchess.org/tests/view/5b31e1230ebc5902b2e5a833 Closes https://github.com/official-stockfish/Stockfish/pull/1647 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: protonspring
Date: Tue Jun 26 09:08:15 2018 +0200 Timestamp: 1529996895 Remove make_bitboard() In current master, the function make_bitboard() does nothing apart from helping initialize the SquareBB[] array. This seems like an unnecessary abstraction layer. The advantage of make_bitboard() is we can define a bitboard, in a simple and general way, not only from a single square but also from a list of squares. It is more elegant, faster and readable than combining multiple SquareBB explicitly, but the last complex use case in evaluation was simplified away a few months ago. If make_bitboard() becomes useful again to define complicated bitboards, it will be easy enough to reintroduce it using this pull request as an implementation reference. 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: joergoster
Date: Tue Jun 26 08:55:35 2018 +0200 Timestamp: 1529996135 Simplify KingProtector penalty. Recent tuning results implied this penalty is more important for knights and bishops, and almost negligible for rooks and queen. Passed as simplification both STC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 20873 W: 4592 L: 4469 D: 11812 Elo +2.05 http://tests.stockfishchess.org/tests/view/5b2fb4d00ebc5902b2e57e84 and LTC LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 46069 W: 7949 L: 7870 D: 30250 Elo +0.60 http://tests.stockfishchess.org/tests/view/5b2fcc4b0ebc5902b2e580c5 Closes https://github.com/official-stockfish/Stockfish/pull/1660 Bench: 5487679 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 Jun 26 08:16:37 2018 +0200 Timestamp: 1529993797 Simplify HinderPassedPawn bonus Make sure each piece is not scored more than once as a passed pawn "hinderer", by scoring only the blockers along the passed pawn path. Inspired by TCEC Game 29. Passed STC as a simplification http://tests.stockfishchess.org/tests/view/5b3016d00ebc5902b2e58552 LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 75388 W: 16656 L: 16641 D: 42091 Elo +0.07 Passed LTC as a simplification http://tests.stockfishchess.org/tests/view/5b302ed90ebc5902b2e587fc LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 49157 W: 8460 L: 8386 D: 32311 Elo +0.52 Current master was also counting the number of attacks along a passed pawn path, which might be misleading: a) a defender might be counted many times for the same pawn path. For example a White rook on a1 attacking a black pawn on a7 would score the bonus * 6 but would be probably better placed on a8 b) a defender might be counted on different pawn paths and might be overloaded. For example a Ke4 or Qe4 against pawns on d6 and f6 would score the bonus * 6. Counting each blocker or attacker only once is more complicated, and does not help either: http://tests.stockfishchess.org/tests/view/5b2ff1cb0ebc5902b2e582b2 After this small simplification, there might be ways to increase the HinderPassedPawn penalty. Closes https://github.com/official-stockfish/Stockfish/pull/1661 Bench: 4520519 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: candirufish
Date: Sat Jun 23 09:03:58 2018 +0200 Timestamp: 1529737438 Another set of tuned values after one million games Another set of tuned values, obtained by a long session of one million games. STC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 15810 W: 3687 L: 3458 D: 8665 Elo +5.03 http://tests.stockfishchess.org/tests/view/5b2d32f60ebc5902b2e55d9e LTC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 102118 W: 18146 L: 17651 D: 66321 Elo +1.68 http://tests.stockfishchess.org/tests/view/5b2d372c0ebc5902b2e55e0a Closes https://github.com/official-stockfish/Stockfish/pull/1658 Bench: 4557946 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: Fri Jun 22 01:29:25 2018 +0200 Timestamp: 1529623765 Increase outflanking weight to 12 Give more incentive to king activity in the endgame by increasing the weight of the "outflanking" variable from 8 to 12 in the function evaluate_initiative(). Finished yellow after 133102 games at STC: LLR: -3.07 (-2.94,2.94) [0.00,4.00] Total: 133102 W: 29535 L: 29179 D: 74388 Elo +0.93 http://tests.stockfishchess.org/tests/view/5b2b63fe0ebc5902b2e54475 Passed LTC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 28027 W: 4918 L: 4672 D: 18437 Elo +3.05 http://tests.stockfishchess.org/tests/view/5b2ba39e0ebc5902b2e54a64 Closes https://github.com/official-stockfish/Stockfish/pull/1657 Bench: 4721753 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: candirufish
Date: Thu Jun 21 10:23:05 2018 +0200 Timestamp: 1529569385 Tuned values after 505k games Various king and pawn tuned eval values after 505k 60 sec 600 nodes time SPSA games. Adjusted passed rank and file values to be symmetrical. Passed LTC (after passed rank/file adjustment): LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 37906 W: 6953 L: 6668 D: 24285 Elo +2.61 http://tests.stockfishchess.org/tests/view/5b2790960ebc5902b8d17ba1 A previous, very similar version with raw tuned values passed STC and LTC: STC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 39515 W: 9227 L: 8900 D: 21388 Elo +2.88 http://tests.stockfishchess.org/tests/view/5b277e3e0ebc5902b8d17ac9 LTC: LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 14618 W: 2743 L: 2537 D: 9338 Elo +4.90 http://tests.stockfishchess.org/tests/view/5b2785020ebc5902b8d17b98 Closes https://github.com/official-stockfish/Stockfish/pull/1654 bench: 4777396 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: Michael An
Date: Thu Jun 21 09:51:31 2018 +0200 Timestamp: 1529567491 Fix GCC 8 cast warnings Silences the following warnings when compiling with GCC 8. The fix is to use an intermediate pointer to anonymous function: ``` misc.cpp: In function 'int WinProcGroup::get_group(size_t)': misc.cpp:241:77: warning: cast between incompatible function types from 'FARPROC' {aka 'long long int (*)()'} to 'fun1_t' {aka 'bool (*)(_LOGICAL_PROCESSOR_RELATIONSHIP, _SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX*, long unsigned int*)'} [-Wcast-function-type] auto fun1 = (fun1_t)GetProcAddress(k32, "GetLogicalProcessorInformationEx"); ^ misc.cpp: In function 'void WinProcGroup::bindThisThread(size_t)': misc.cpp:309:71: warning: cast between incompatible function types from 'FARPROC' {aka 'long long int (*)()'} to 'fun2_t' {aka 'bool (*)(short unsigned int, _GROUP_AFFINITY*)'} [-Wcast-function-type] auto fun2 = (fun2_t)GetProcAddress(k32, "GetNumaNodeProcessorMaskEx"); ^ misc.cpp:310:67: warning: cast between incompatible function types from 'FARPROC' {aka 'long long int (*)()'} to 'fun3_t' {aka 'bool (*)(void*, const _GROUP_AFFINITY*, _GROUP_AFFINITY*)'} [-Wcast-function-type] auto fun3 = (fun3_t)GetProcAddress(k32, "SetThreadGroupAffinity"); ^ ``` 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: mstembera
Date: Wed Jun 20 05:43:00 2018 +0200 Timestamp: 1529466180 Fix MSVC error Compiling the current master with MSVC gives the following error: ``` search.cpp(956): error C2660: 'operator *': function does not take 1 arguments types.h(303): note: see declaration of 'operator *' ``` This was introduced in commit: https://github.com/official-stockfish/Stockfish/commit/88de112b84a5285c2afb3e075a05c2ab8ad3fd33 We use a suggestion by @vondele to fix the error, thanks! 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: Stefano80
Date: Wed Jun 20 05:27:24 2018 +0200 Timestamp: 1529465244 Slight simplification in scale factor computation [STC](http://tests.stockfishchess.org/tests/view/5b2614000ebc5902b8d17193) LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 17733 W: 3996 L: 3866 D: 9871 Elo +2.55 [LTC](http://tests.stockfishchess.org/tests/view/5b264d0f0ebc5902b8d17206) LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 55524 W: 9535 L: 9471 D: 36518 Elo +0.40 Use pawn count scaling also for opposite bishops endings with additional material, with a slope of 2 instead of 7. This simplifies slightly the code. This PR is a functionally equivalent refactoring of the version which was submitted. Four versions tried, 2 passed both STC and LTC. I picked the one which seemed more promising at LTC. Slope 4 passed STC (-0.54 Elo), LTC not attempted Slope 3 passed STC (+2.51 Elo), LTC (-0.44 Elo) Slope 2 passed STC (+2.09 Elo), LTC (+0.04 Elo) Slope 1 passed STC (+0.90 Elo), failed LTC (-3.40 Elo) Bench: 4761613 see source |