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Merge remote-tracking branch 'remotes/nodchip/master' into trainer

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noobpwnftw
2020-09-09 23:35:41 +08:00
parent b3a0ded37a 9dcadfa642
commit a47a3bfc7c
15 changed files with 257 additions and 180 deletions
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48
src/uci.cpp
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@@ -70,7 +70,7 @@ void test_cmd(Position& pos, istringstream& is)
if (param == "nnue") Eval::NNUE::TestCommand(pos, is);
}
namespace {
namespace UCI {
// position() is called when engine receives the "position" UCI command.
// The function sets up the position described in the given FEN string ("fen")
@@ -229,33 +229,33 @@ namespace {
// and a game-ply. The model fits rather accurately the LTC fishtest statistics.
int win_rate_model(Value v, int ply) {
// Return win rate in per mille (rounded to nearest)
return int(0.5 + UCI::win_rate_model_double(v, ply));
return int(0.5 + win_rate_model_double(v, ply));
}
// The win rate model returns the probability (per mille) of winning given an eval
// and a game-ply. The model fits rather accurately the LTC fishtest statistics.
double win_rate_model_double(double v, int ply) {
// The model captures only up to 240 plies, so limit input (and rescale)
double m = std::min(240, ply) / 64.0;
// Coefficients of a 3rd order polynomial fit based on fishtest data
// for two parameters needed to transform eval to the argument of a
// logistic function.
double as[] = {-8.24404295, 64.23892342, -95.73056462, 153.86478679};
double bs[] = {-3.37154371, 28.44489198, -56.67657741, 72.05858751};
double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
// Transform eval to centipawns with limited range
double x = std::clamp(double(100 * v) / PawnValueEg, -1000.0, 1000.0);
// Return win rate in per mille
return 1000.0 / (1 + std::exp((a - x) / b));
}
} // namespace
// The win rate model returns the probability (per mille) of winning given an eval
// and a game-ply. The model fits rather accurately the LTC fishtest statistics.
double UCI::win_rate_model_double(double v, int ply) {
// The model captures only up to 240 plies, so limit input (and rescale)
double m = std::min(240, ply) / 64.0;
// Coefficients of a 3rd order polynomial fit based on fishtest data
// for two parameters needed to transform eval to the argument of a
// logistic function.
double as[] = {-8.24404295, 64.23892342, -95.73056462, 153.86478679};
double bs[] = {-3.37154371, 28.44489198, -56.67657741, 72.05858751};
double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
// Transform eval to centipawns with limited range
double x = std::clamp(double(100 * v) / PawnValueEg, -1000.0, 1000.0);
// Return win rate in per mille
return 1000.0 / (1 + std::exp((a - x) / b));
}
// --------------------
// Call qsearch(),search() directly for testing
// --------------------