X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftimeman.cpp;h=b5d1a66c30b05faf1d26da029ebd42ab7bbdfe8a;hp=bc9c2e5b4b7876025d9cf86126cdeec4f242a633;hb=daf0fe1f57337d33f9e0af5a8aa8ef0868b20417;hpb=d5ba8e827d840995e79435986a8a7a2a45626eca diff --git a/src/timeman.cpp b/src/timeman.cpp index bc9c2e5b..b5d1a66c 100644 --- a/src/timeman.cpp +++ b/src/timeman.cpp @@ -2,7 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -19,8 +19,6 @@ */ #include -#include -#include #include "search.h" #include "timeman.h" @@ -32,41 +30,50 @@ namespace { enum TimeType { OptimumTime, MaxTime }; - const int MoveHorizon = 50; // Plan time management at most this many moves ahead - const double MaxRatio = 7.09; // When in trouble, we can step over reserved time with this ratio - const double StealRatio = 0.35; // However we must not steal time from remaining moves over this ratio + int remaining(int myTime, int myInc, int moveOverhead, int movesToGo, + int ply, bool ponder, TimeType type) { + if (myTime <= 0) + return 0; - // move_importance() is a skew-logistic function based on naive statistical - // analysis of "how many games are still undecided after n half-moves". Game - // is considered "undecided" as long as neither side has >275cp advantage. - // Data was extracted from the CCRL game database with some simple filtering criteria. + int moveNumber = (ply + 1) / 2; + double ratio; // Which ratio of myTime we are going to use. It's <= 1 if not ponder + double sd = 8.5; - double move_importance(int ply) { + // Usage of increment follows quadratic distribution with the maximum at move 25 + double inc = myInc * std::max(55.0, 120.0 - 0.12 * (moveNumber - 25) * (moveNumber - 25)); - const double XScale = 7.64; - const double XShift = 58.4; - const double Skew = 0.183; + // In moves-to-go we distribute time according to a quadratic function with + // the maximum around move 20 for 40 moves in y time case. + if (movesToGo) + { + ratio = (type == OptimumTime ? 1.0 : 6.0) / std::min(50, movesToGo); - return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero - } + if (moveNumber <= 40) + ratio *= 1.1 - 0.001 * (moveNumber - 20) * (moveNumber - 20); + else + ratio *= 1.5; + } + // Otherwise we increase usage of remaining time as the game goes on + else + { + sd = 1 + 20 * moveNumber / (500.0 + moveNumber); + ratio = (type == OptimumTime ? 0.017 : 0.07) * sd; + } - template - int remaining(int myTime, int movesToGo, int ply, int slowMover) - { - const double TMaxRatio = (T == OptimumTime ? 1 : MaxRatio); - const double TStealRatio = (T == OptimumTime ? 0 : StealRatio); + ratio = std::min(1.0, ratio * (1 + inc / (myTime * sd))); + + assert(ratio <= 1); - double moveImportance = (move_importance(ply) * slowMover) / 100; - double otherMovesImportance = 0; + if (ponder && type == OptimumTime) + ratio *= 1.25; - for (int i = 1; i < movesToGo; ++i) - otherMovesImportance += move_importance(ply + 2 * i); + int time = int(ratio * (myTime - moveOverhead)); - double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance); - double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance); + if (type == OptimumTime) + time -= 10; // Keep always at least 10 millisecs on the clock - return int(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast + return std::max(0, time); } } // namespace @@ -83,10 +90,9 @@ namespace { void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { - int minThinkingTime = Options["Minimum Thinking Time"]; - int moveOverhead = Options["Move Overhead"]; - int slowMover = Options["Slow Mover"]; - int npmsec = Options["nodestime"]; + int moveOverhead = Options["Move Overhead"]; + int npmsec = Options["nodestime"]; + bool ponder = Options["Ponder"]; // If we have to play in 'nodes as time' mode, then convert from time // to nodes, and use resulting values in time management formulas. @@ -104,29 +110,8 @@ void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) } startTime = limits.startTime; - optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime); - - const int MaxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon; - - // We calculate optimum time usage for different hypothetical "moves to go"-values - // and choose the minimum of calculated search time values. Usually the greatest - // hypMTG gives the minimum values. - for (int hypMTG = 1; hypMTG <= MaxMTG; ++hypMTG) - { - // Calculate thinking time for hypothetical "moves to go"-value - int hypMyTime = limits.time[us] - + limits.inc[us] * (hypMTG - 1) - - moveOverhead * (2 + std::min(hypMTG, 40)); - - hypMyTime = std::max(hypMyTime, 0); - - int t1 = minThinkingTime + remaining(hypMyTime, hypMTG, ply, slowMover); - int t2 = minThinkingTime + remaining(hypMyTime, hypMTG, ply, slowMover); - - optimumTime = std::min(t1, optimumTime); - maximumTime = std::min(t2, maximumTime); - } - - if (Options["Ponder"]) - optimumTime += optimumTime / 4; + optimumTime = remaining(limits.time[us], limits.inc[us], moveOverhead, + limits.movestogo, ply, ponder, OptimumTime); + maximumTime = remaining(limits.time[us], limits.inc[us], moveOverhead, + limits.movestogo, ply, ponder, MaxTime); }