Skip to content

Commit dc49833

Browse files
committed
Update WDL model for NNUE
This updates the WDL model based on the LTC statistics in June this year (10M games), so from pre-NNUE to NNUE based results. (for old results see, official-stockfish#2778) As before the fit by the model to the data is quite good. closes official-stockfish#3582 No functional change
1 parent e47b744 commit dc49833

File tree

1 file changed

+3
-3
lines changed

1 file changed

+3
-3
lines changed

src/uci.cpp

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -207,13 +207,13 @@ namespace {
207207
// Coefficients of a 3rd order polynomial fit based on fishtest data
208208
// for two parameters needed to transform eval to the argument of a
209209
// logistic function.
210-
double as[] = {-8.24404295, 64.23892342, -95.73056462, 153.86478679};
211-
double bs[] = {-3.37154371, 28.44489198, -56.67657741, 72.05858751};
210+
double as[] = {-3.68389304, 30.07065921, -60.52878723, 149.53378557};
211+
double bs[] = {-2.0181857, 15.85685038, -29.83452023, 47.59078827};
212212
double a = (((as[0] * m + as[1]) * m + as[2]) * m) + as[3];
213213
double b = (((bs[0] * m + bs[1]) * m + bs[2]) * m) + bs[3];
214214

215215
// Transform eval to centipawns with limited range
216-
double x = std::clamp(double(100 * v) / PawnValueEg, -1000.0, 1000.0);
216+
double x = std::clamp(double(100 * v) / PawnValueEg, -2000.0, 2000.0);
217217

218218
// Return win rate in per mille (rounded to nearest)
219219
return int(0.5 + 1000 / (1 + std::exp((a - x) / b)));

0 commit comments

Comments
 (0)