/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2022 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include <sstream>
#include <string>
+#include "benchmark.h"
#include "evaluate.h"
#include "movegen.h"
#include "position.h"
namespace Stockfish {
-extern vector<string> setup_bench(const Position&, istream&);
-
namespace {
// FEN string for the initial position in standard chess
uint64_t num, nodes = 0, cnt = 1;
vector<string> list = setup_bench(pos, args);
- num = count_if(list.begin(), list.end(), [](string s) { return s.find("go ") == 0 || s.find("eval") == 0; });
+ num = count_if(list.begin(), list.end(), [](const string& s) { return s.find("go ") == 0 || s.find("eval") == 0; });
TimePoint elapsed = now();
// The coefficients of a third-order polynomial fit is based on the fishtest data
// for two parameters that need to transform eval to the argument of a logistic
// function.
- double as[] = { 0.50379905, -4.12755858, 18.95487051, 152.00733652};
- double bs[] = {-1.71790378, 10.71543602, -17.05515898, 41.15680404};
+ constexpr double as[] = { 0.33677609, -4.30175627, 33.08810557, 365.60223431};
+ constexpr double bs[] = { -2.50471102, 14.23235405, -14.33066859, 71.42705250 };
+
+ // Enforce that NormalizeToPawnValue corresponds to a 50% win rate at ply 64
+ static_assert(UCI::NormalizeToPawnValue == int(as[0] + as[1] + as[2] + as[3]));
+
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 the eval to centipawns with limited range
- double x = std::clamp(double(100 * v) / PawnValueEg, -2000.0, 2000.0);
+ double x = std::clamp(double(v), -4000.0, 4000.0);
// Return the win rate in per mille units rounded to the nearest value
return int(0.5 + 1000 / (1 + std::exp((a - x) / b)));
stringstream ss;
- if (abs(v) < VALUE_MATE_IN_MAX_PLY)
- ss << "cp " << v * 100 / PawnValueEg;
+ if (abs(v) < VALUE_TB_WIN_IN_MAX_PLY)
+ ss << "cp " << v * 100 / NormalizeToPawnValue;
+ else if (abs(v) < VALUE_MATE_IN_MAX_PLY)
+ {
+ const int ply = VALUE_MATE_IN_MAX_PLY - 1 - std::abs(v); // recompute ss->ply
+ ss << "cp " << (v > 0 ? 20000 - ply : -20000 + ply);
+ }
else
ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;