Simplify blending nnue complexity with optimism

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 7239fd1eca04d8937d25021f447ece9edfdb316d..bf6dd69a950282588c904d5f60b0305f9eb9b319 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -1070,12 +1070,8 @@ Value Eval::evaluate(const Position& pos) {
 
       Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
 
-      // Blend nnue complexity with (semi)classical complexity
-      nnueComplexity = (  397 * nnueComplexity
-                        + 477 * abs(psq - nnue)
-                        ) / 1024;
-
-      optimism += optimism * nnueComplexity / 256;
+      // Blend optimism with nnue complexity and (semi)classical complexity
+      optimism += 25 * optimism * (nnueComplexity + abs(psq - nnue)) / 16384;
       v = (nnue * (945 + npm) + optimism * (174 + npm)) / 1024;
   }