From 2054add23cf234f302c67709efc0d265c5a98eae Mon Sep 17 00:00:00 2001
From: "Robert Nurnberg @ elitebook" <robert.nurnberg@gmx.de>
Date: Tue, 3 Sep 2024 08:20:06 +0200
Subject: [PATCH] Update the WDL model

updates the internal WDL model, using data from 2.6M games played by the revisions since 9fb5832.

https://github.com/official-stockfish/Stockfish/pull/5565

No functional change
---
 src/uci.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/uci.cpp b/src/uci.cpp
index 9b60680d..c94f8b91 100644
--- a/src/uci.cpp
+++ b/src/uci.cpp
@@ -339,8 +339,8 @@ WinRateParams win_rate_params(const Position& pos) {
     double m = std::clamp(material, 17, 78) / 58.0;
 
     // Return a = p_a(material) and b = p_b(material), see github.com/official-stockfish/WDL_model
-    constexpr double as[] = {-41.25712052, 121.47473115, -124.46958843, 411.84490997};
-    constexpr double bs[] = {84.92998051, -143.66658718, 80.09988253, 49.80869370};
+    constexpr double as[] = {-37.45051876, 121.19101539, -132.78783573, 420.70576692};
+    constexpr double bs[] = {90.26261072, -137.26549898, 71.10130540, 51.35259597};
 
     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];