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| 4 | Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad |
4 | Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad |
| 5 | Copyright (C) 2015- |
5 | Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad |
| 6 | 6 | ||
| 7 | Stockfish is free software: you can redistribute it and/or modify |
7 | Stockfish is free software: you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation, either version 3 of the License, or |
9 | the Free Software Foundation, either version 3 of the License, or |
| 10 | (at your option) any later version. |
10 | (at your option) any later version. |
| Line 30... | Line 30... | ||
| 30 | 30 | ||
| 31 | namespace { |
31 | namespace { |
| 32 | 32 | ||
| 33 | enum TimeType { OptimumTime, MaxTime }; |
33 | enum TimeType { OptimumTime, MaxTime }; |
| 34 | 34 | ||
| 35 |
|
35 | constexpr int MoveHorizon = 50; // Plan time management at most this many moves ahead |
| 36 |
|
36 | constexpr double MaxRatio = 7.3; // When in trouble, we can step over reserved time with this ratio |
| 37 |
|
37 | constexpr double StealRatio = 0.34; // However we must not steal time from remaining moves over this ratio |
| 38 | 38 | ||
| 39 | 39 | ||
| 40 | // move_importance() is a skew-logistic function based on naive statistical |
40 | // move_importance() is a skew-logistic function based on naive statistical |
| 41 | // analysis of "how many games are still undecided after n half-moves". Game |
41 | // analysis of "how many games are still undecided after n half-moves". Game |
| 42 | // is considered "undecided" as long as neither side has >275cp advantage. |
42 | // is considered "undecided" as long as neither side has >275cp advantage. |
| 43 | // Data was extracted from the CCRL game database with some simple filtering criteria. |
43 | // Data was extracted from the CCRL game database with some simple filtering criteria. |
| 44 | 44 | ||
| 45 | double move_importance(int ply) { |
45 | double move_importance(int ply) { |
| 46 | 46 | ||
| 47 |
|
47 | constexpr double XScale = 6.85; |
| 48 |
|
48 | constexpr double XShift = 64.5; |
| 49 |
|
49 | constexpr double Skew = 0.171; |
| 50 | 50 | ||
| 51 | return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero |
51 | return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero |
| 52 | } |
52 | } |
| 53 | 53 | ||
| 54 | template<TimeType T> |
54 | template<TimeType T> |
| 55 |
|
55 | TimePoint remaining(TimePoint myTime, int movesToGo, int ply, TimePoint slowMover) { |
| 56 | 56 | ||
| 57 |
|
57 | constexpr double TMaxRatio = (T == OptimumTime ? 1.0 : MaxRatio); |
| 58 |
|
58 | constexpr double TStealRatio = (T == OptimumTime ? 0.0 : StealRatio); |
| 59 | 59 | ||
| 60 | double moveImportance = (move_importance(ply) * slowMover) / |
60 | double moveImportance = (move_importance(ply) * slowMover) / 100.0; |
| 61 | double otherMovesImportance = |
61 | double otherMovesImportance = 0.0; |
| 62 | 62 | ||
| 63 | for (int i = 1; i < movesToGo; ++i) |
63 | for (int i = 1; i < movesToGo; ++i) |
| 64 | otherMovesImportance += move_importance(ply + 2 * i); |
64 | otherMovesImportance += move_importance(ply + 2 * i); |
| 65 | 65 | ||
| 66 | double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance); |
66 | double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance); |
| 67 | double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance); |
67 | double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance); |
| 68 | 68 | ||
| 69 | return |
69 | return TimePoint(myTime * std::min(ratio1, ratio2)); // Intel C++ asks for an explicit cast |
| 70 | } |
70 | } |
| 71 | 71 | ||
| 72 | } // namespace |
72 | } // namespace |
| 73 | 73 | ||
| 74 | 74 | ||
| Line 81... | Line 81... | ||
| 81 | /// inc > 0 && movestogo == 0 means: x basetime + z increment |
81 | /// inc > 0 && movestogo == 0 means: x basetime + z increment |
| 82 | /// inc > 0 && movestogo != 0 means: x moves in y minutes + z increment |
82 | /// inc > 0 && movestogo != 0 means: x moves in y minutes + z increment |
| 83 | 83 | ||
| 84 | void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { |
84 | void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) { |
| 85 | 85 | ||
| 86 |
|
86 | TimePoint minThinkingTime = Options["Minimum Thinking Time"]; |
| 87 |
|
87 | TimePoint moveOverhead = Options["Move Overhead"]; |
| 88 |
|
88 | TimePoint slowMover = Options["Slow Mover"]; |
| 89 |
|
89 | TimePoint npmsec = Options["nodestime"]; |
| - | 90 | TimePoint hypMyTime; |
|
| 90 | 91 | ||
| 91 | // If we have to play in 'nodes as time' mode, then convert from time |
92 | // If we have to play in 'nodes as time' mode, then convert from time |
| 92 | // to nodes, and use resulting values in time management formulas. |
93 | // to nodes, and use resulting values in time management formulas. |
| 93 | // WARNING: |
94 | // WARNING: to avoid time losses, the given npmsec (nodes per millisecond) |
| 94 | // |
95 | // must be much lower than the real engine speed. |
| 95 | if (npmsec) |
96 | if (npmsec) |
| 96 | { |
97 | { |
| 97 | if (!availableNodes) // Only once at game start |
98 | if (!availableNodes) // Only once at game start |
| 98 | availableNodes = npmsec * limits.time[us]; // Time is in msec |
99 | availableNodes = npmsec * limits.time[us]; // Time is in msec |
| 99 | 100 | ||
| 100 | // Convert from |
101 | // Convert from milliseconds to nodes |
| 101 | limits.time[us] = ( |
102 | limits.time[us] = TimePoint(availableNodes); |
| 102 | limits.inc[us] *= npmsec; |
103 | limits.inc[us] *= npmsec; |
| 103 | limits.npmsec = npmsec; |
104 | limits.npmsec = npmsec; |
| 104 | } |
105 | } |
| 105 | 106 | ||
| 106 | startTime = limits.startTime; |
107 | startTime = limits.startTime; |
| 107 | optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime); |
108 | optimumTime = maximumTime = std::max(limits.time[us], minThinkingTime); |
| 108 | 109 | ||
| 109 | const int |
110 | const int maxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon; |
| 110 | 111 | ||
| 111 | // We calculate optimum time usage for different hypothetical "moves to go" |
112 | // We calculate optimum time usage for different hypothetical "moves to go" values |
| 112 | // and choose the minimum of calculated search time values. Usually the greatest |
113 | // and choose the minimum of calculated search time values. Usually the greatest |
| 113 | // hypMTG gives the minimum values. |
114 | // hypMTG gives the minimum values. |
| 114 | for (int hypMTG = 1; hypMTG <= |
115 | for (int hypMTG = 1; hypMTG <= maxMTG; ++hypMTG) |
| 115 | { |
116 | { |
| 116 | // Calculate thinking time for hypothetical "moves to go"-value |
117 | // Calculate thinking time for hypothetical "moves to go"-value |
| 117 |
|
118 | hypMyTime = limits.time[us] |
| 118 |
|
119 | + limits.inc[us] * (hypMTG - 1) |
| 119 |
|
120 | - moveOverhead * (2 + std::min(hypMTG, 40)); |
| 120 | 121 | ||
| 121 | hypMyTime = std::max(hypMyTime, 0); |
122 | hypMyTime = std::max(hypMyTime, TimePoint(0)); |
| 122 | 123 | ||
| 123 |
|
124 | TimePoint t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover); |
| 124 |
|
125 | TimePoint t2 = minThinkingTime + remaining<MaxTime >(hypMyTime, hypMTG, ply, slowMover); |
| 125 | 126 | ||
| 126 | optimumTime = std::min(t1, optimumTime); |
127 | optimumTime = std::min(t1, optimumTime); |
| 127 | maximumTime = std::min(t2, maximumTime); |
128 | maximumTime = std::min(t2, maximumTime); |
| 128 | } |
129 | } |
| 129 | 130 | ||