2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
29 #include "ucioption.h"
32 //// Local definitions
39 const int MoveHorizon = 50; // Plan time management at most this many moves ahead
40 const float MaxRatio = 3.0f; // When in trouble, we can step over reserved time with this ratio
41 const float StealRatio = 0.33f; // However we must not steal time from remaining moves over this ratio
44 // MoveImportance[] is based on naive statistical analysis of "how many games are still undecided
45 // after n half-moves". Game is considered "undecided" as long as neither side has >275cp advantage.
46 // Data was extracted from CCRL game database with some simple filtering criteria.
47 const int MoveImportance[512] = {
48 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780, 7780,
49 7780, 7780, 7780, 7780, 7778, 7778, 7776, 7776, 7776, 7773, 7770, 7768, 7766, 7763, 7757, 7751,
50 7743, 7735, 7724, 7713, 7696, 7689, 7670, 7656, 7627, 7605, 7571, 7549, 7522, 7493, 7462, 7425,
51 7385, 7350, 7308, 7272, 7230, 7180, 7139, 7094, 7055, 7010, 6959, 6902, 6841, 6778, 6705, 6651,
52 6569, 6508, 6435, 6378, 6323, 6253, 6152, 6085, 5995, 5931, 5859, 5794, 5717, 5646, 5544, 5462,
53 5364, 5282, 5172, 5078, 4988, 4901, 4831, 4764, 4688, 4609, 4536, 4443, 4365, 4293, 4225, 4155,
54 4085, 4005, 3927, 3844, 3765, 3693, 3634, 3560, 3479, 3404, 3331, 3268, 3207, 3146, 3077, 3011,
55 2947, 2894, 2828, 2776, 2727, 2676, 2626, 2589, 2538, 2490, 2442, 2394, 2345, 2302, 2243, 2192,
56 2156, 2115, 2078, 2043, 2004, 1967, 1922, 1893, 1845, 1809, 1772, 1736, 1702, 1674, 1640, 1605,
57 1566, 1536, 1509, 1479, 1452, 1423, 1388, 1362, 1332, 1304, 1289, 1266, 1250, 1228, 1206, 1180,
58 1160, 1134, 1118, 1100, 1080, 1068, 1051, 1034, 1012, 1001, 980, 960, 945, 934, 916, 900, 888,
59 878, 865, 852, 828, 807, 787, 770, 753, 744, 731, 722, 706, 700, 683, 676, 671, 664, 652, 641,
60 634, 627, 613, 604, 591, 582, 568, 560, 552, 540, 534, 529, 519, 509, 495, 484, 474, 467, 460,
61 450, 438, 427, 419, 410, 406, 399, 394, 387, 382, 377, 372, 366, 359, 353, 348, 343, 337, 333,
62 328, 321, 315, 309, 303, 298, 293, 287, 284, 281, 277, 273, 265, 261, 255, 251, 247, 241, 240,
63 235, 229, 218, 217, 213, 212, 208, 206, 197, 193, 191, 189, 185, 184, 180, 177, 172, 170, 170,
64 170, 166, 163, 159, 158, 156, 155, 151, 146, 141, 138, 136, 132, 130, 128, 125, 123, 122, 118,
65 118, 118, 117, 115, 114, 108, 107, 105, 105, 105, 102, 97, 97, 95, 94, 93, 91, 88, 86, 83, 80,
66 80, 79, 79, 79, 78, 76, 75, 72, 72, 71, 70, 68, 65, 63, 61, 61, 59, 59, 59, 58, 56, 55, 54, 54,
67 52, 49, 48, 48, 48, 48, 45, 45, 45, 44, 43, 41, 41, 41, 41, 40, 40, 38, 37, 36, 34, 34, 34, 33,
68 31, 29, 29, 29, 28, 28, 28, 28, 28, 28, 28, 27, 27, 27, 27, 27, 24, 24, 23, 23, 22, 21, 20, 20,
69 19, 19, 19, 19, 19, 18, 18, 18, 18, 17, 17, 17, 17, 17, 16, 16, 15, 15, 14, 14, 14, 12, 12, 11,
70 9, 9, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
71 8, 8, 8, 8, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
72 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2,
73 2, 1, 1, 1, 1, 1, 1, 1 };
75 int move_importance(int ply) { return MoveImportance[Min(ply, 511)]; }
78 /// Function Prototypes
80 enum TimeType { OptimumTime, MaxTime };
83 int remaining(int myTime, int movesToGo, int currentPly);
91 void TimeManager::pv_instability(int curChanges, int prevChanges) {
93 unstablePVExtraTime = curChanges * (optimumSearchTime / 2)
94 + prevChanges * (optimumSearchTime / 3);
97 void TimeManager::init(int myTime, int myInc, int movesToGo, int currentPly)
99 /* We support four different kind of time controls:
101 Inc == 0 && movesToGo == 0 means: x basetime [sudden death!]
102 Inc == 0 && movesToGo != 0 means: (x moves) / (y minutes)
103 Inc > 0 && movesToGo == 0 means: x basetime + z inc.
104 Inc > 0 && movesToGo != 0 means: (x moves) / (y minutes) + z inc
106 Time management is adjusted by following UCI parameters:
108 emergencyMoveHorizon :Be prepared to always play at least this many moves
109 emergencyBaseTime :Always attempt to keep at least this much time (in ms) at clock
110 emergencyMoveTime :Plus attempt to keep at least this much time for each remaining emergency move
111 minThinkingTime :No matter what, use at least this much thinking before doing the move
114 int hypMTG, hypMyTime, t1, t2;
116 // Read uci parameters
117 int emergencyMoveHorizon = Options["Emergency Move Horizon"].value<int>();
118 int emergencyBaseTime = Options["Emergency Base Time"].value<int>();
119 int emergencyMoveTime = Options["Emergency Move Time"].value<int>();
120 int minThinkingTime = Options["Minimum Thinking Time"].value<int>();
122 // Initialize to maximum values but unstablePVExtraTime that is reset
123 unstablePVExtraTime = 0;
124 optimumSearchTime = maximumSearchTime = myTime;
126 // We calculate optimum time usage for different hypothetic "moves to go"-values and choose the
127 // minimum of calculated search time values. Usually the greatest hypMTG gives the minimum values.
128 for (hypMTG = 1; hypMTG <= (movesToGo ? Min(movesToGo, MoveHorizon) : MoveHorizon); hypMTG++)
130 // Calculate thinking time for hypothetic "moves to go"-value
131 hypMyTime = Max(myTime + (hypMTG - 1) * myInc - emergencyBaseTime - Min(hypMTG, emergencyMoveHorizon) * emergencyMoveTime, 0);
133 t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, currentPly);
134 t2 = minThinkingTime + remaining<MaxTime>(hypMyTime, hypMTG, currentPly);
136 optimumSearchTime = Min(optimumSearchTime, t1);
137 maximumSearchTime = Min(maximumSearchTime, t2);
140 if (Options["Ponder"].value<bool>())
141 optimumSearchTime += optimumSearchTime / 4;
143 // Make sure that maxSearchTime is not over absoluteMaxSearchTime
144 optimumSearchTime = Min(optimumSearchTime, maximumSearchTime);
154 int remaining(int myTime, int movesToGo, int currentPly)
156 const float TMaxRatio = (T == OptimumTime ? 1 : MaxRatio);
157 const float TStealRatio = (T == OptimumTime ? 0 : StealRatio);
159 int thisMoveImportance = move_importance(currentPly);
160 int otherMovesImportance = 0;
162 for (int i = 1; i < movesToGo; i++)
163 otherMovesImportance += move_importance(currentPly + 2 * i);
165 float ratio1 = (TMaxRatio * thisMoveImportance) / float(TMaxRatio * thisMoveImportance + otherMovesImportance);
166 float ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / float(thisMoveImportance + otherMovesImportance);
168 return int(floor(myTime * Min(ratio1, ratio2)));