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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 |
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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 |