Remove optimism multiplier in nnue eval calculation

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 40c43d230434a910e9451b926d4f5fba5ae39ca3..35d054270ee7120e1f0438f58867248146053edc 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -1070,11 +1070,9 @@ Value Eval::evaluate(const Position& pos) {
 
       Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
 
-      // Blend nnue complexity with (semi)classical complexity
-      nnueComplexity = 25 * (nnueComplexity + abs(psq - nnue)) / 64;
-
-      optimism += optimism * nnueComplexity / 256;
-      v = (nnue * (945 + npm) + optimism * (174 + npm)) / 1024;
+      // Blend optimism with nnue complexity and (semi)classical complexity
+      optimism += optimism * (nnueComplexity + abs(psq - nnue)) / 512;
+      v = (nnue * (945 + npm) + optimism * (150 + npm)) / 1024;
   }
 
   // Damp down the evaluation linearly when shuffling