Try to match relative magnitude of NNUE eval to classical

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 00fd2005ed7445008263db7f71c547c72a3ef997..a453fa0f7f4cd871a821fbe38827695f05bfc694 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -941,11 +941,14 @@ Value Eval::evaluate(const Position& pos) {
   bool classical = !Eval::useNNUE
                 ||  abs(eg_value(pos.psq_score())) >= NNUEThreshold;
   Value v = classical ? Evaluation<NO_TRACE>(pos).value()
-                      : NNUE::evaluate(pos) + Tempo;
+                      : NNUE::evaluate(pos) * 5 / 4 + Tempo;
 
   // Damp down the evaluation linearly when shuffling
   v = v * (100 - pos.rule50_count()) / 100;
 
+  // Guarantee evalution outside of TB range
+  v = Utility::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
+
   return v;
 }