X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftimeman.cpp;h=035fe33511db8669f5a2b4634bd92af5fb5ecc22;hp=ea1e92d2aca5ca57ef0c6c2a6942ea2717d65753;hb=aa88261a8f509fdabfe235042de1c1ea7a39a399;hpb=e10255339fc7cb54bb0466945f759646f442f4f0 diff --git a/src/timeman.cpp b/src/timeman.cpp index ea1e92d2..035fe335 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) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2018 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 @@ -19,6 +19,8 @@ */ #include +#include +#include #include "search.h" #include "timeman.h" @@ -30,46 +32,41 @@ namespace { enum TimeType { OptimumTime, MaxTime }; - int remaining(int myTime, int myInc, int moveOverhead, int movesToGo, - int moveNum, bool ponder, TimeType type) { + 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 - if (myTime <= 0) - return 0; - double ratio; // Which ratio of myTime we are going to use + // 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. - // Usage of increment follows quadratic distribution with the maximum at move 25 - double inc = myInc * std::max(55.0, 120 - 0.12 * (moveNum - 25) * (moveNum - 25)); + double move_importance(int ply) { - // 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); + const double XScale = 7.64; + const double XShift = 58.4; + const double Skew = 0.183; - if (moveNum <= 40) - ratio *= 1.1 - 0.001 * (moveNum - 20) * (moveNum - 20); - else - ratio *= 1.5; + return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero + } + + template + int remaining(int myTime, int movesToGo, int ply, int slowMover) { - ratio *= 1 + inc / (myTime * 8.5); - } - // Otherwise we increase usage of remaining time as the game goes on - else - { - double k = 1 + 20 * moveNum / (500.0 + moveNum); - ratio = (type == OptimumTime ? 0.017 : 0.07) * (k + inc / myTime); - } + const double TMaxRatio = (T == OptimumTime ? 1 : MaxRatio); + const double TStealRatio = (T == OptimumTime ? 0 : StealRatio); - int time = int(std::min(1.0, ratio) * std::max(0, myTime - moveOverhead)); + double moveImportance = (move_importance(ply) * slowMover) / 100; + double otherMovesImportance = 0; - if (type == OptimumTime && ponder) - time *= 1.25; + for (int i = 1; i < movesToGo; ++i) + otherMovesImportance += move_importance(ply + 2 * i); - if (type == MaxTime) - time -= 10; // Keep always at least 10 millisecs on the clock + double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance); + double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance); - return std::max(0, time); + return int(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast } } // namespace @@ -84,11 +81,12 @@ namespace { /// inc > 0 && movestogo == 0 means: x basetime + z increment /// inc > 0 && movestogo != 0 means: x moves in y minutes + z increment -void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) -{ - int moveOverhead = Options["Move Overhead"]; - int npmsec = Options["nodestime"]; - bool ponder = Options["Ponder"]; +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"]; // If we have to play in 'nodes as time' mode, then convert from time // to nodes, and use resulting values in time management formulas. @@ -105,11 +103,30 @@ void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) limits.npmsec = npmsec; } - int moveNum = (ply + 1) / 2; - startTime = limits.startTime; - optimumTime = remaining(limits.time[us], limits.inc[us], moveOverhead, - limits.movestogo, moveNum, ponder, OptimumTime); - maximumTime = remaining(limits.time[us], limits.inc[us], moveOverhead, - limits.movestogo, moveNum, ponder, MaxTime); + 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; }