kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-29 16:23:09 +00:00
Code Issues Releases Wiki Activity

Update the WDL model

Browse source 
Based on 130M positions from 2.1M games.

```
Look recursively in directory pgns for games from SPRT tests using books
matching "UHO_4060_v..epd|UHO_Lichess_4852_v1.epd" for SF revisions
between 8e75548f2a (from 2024-02-17
17:11:46 +0100) and HEAD (from 2024-02-17 17:13:07 +0100). Based on
127920843 positions from 2109240 games, NormalizeToPawnValue should
change from 345 to 356.
```

The patch only affects the UCI-reported cp and wdl values.

closes https://github.com/official-stockfish/Stockfish/pull/5070

No functional change
This commit is contained in:
Robert Nurnberg @ elitebook 2024-02-24 17:55:08 +01:00 • committed by Disservin
parent bec83a1869
commit 5c2b385957
1 changed files with 3 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
src/uci.cpp
View file

@ -45,7 +45,7 @@
namespace Stockfish {
constexpr auto StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
constexpr int NormalizeToPawnValue = 345;
constexpr int NormalizeToPawnValue = 356;
constexpr int MaxHashMB = Is64Bit ? 33554432 : 2048;
UCI::UCI(int argc, char** argv) :
@ -380,8 +380,8 @@ int win_rate_model(Value v, int ply) {
// 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.
constexpr double as[] = {-2.00568292, 10.45906746, 1.67438883, 334.45864705};
constexpr double bs[] = {-4.97134419, 36.15096345, -82.25513499, 117.35186805};
constexpr double as[] = {-1.06249702, 7.42016937, 0.89425629, 348.60356174};
constexpr double bs[] = {-5.33122190, 39.57831533, -90.84473771, 123.40620748};
// Enforce that NormalizeToPawnValue corresponds to a 50% win rate at move 32.
static_assert(NormalizeToPawnValue == int(0.5 + as[0] + as[1] + as[2] + as[3]));