Divide piece score by 2 for drop variants

STC
LLR: 2.97 (-2.94,2.94) [0.00,10.00]
Total: 302 W: 202 L: 96 D: 4

LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 262 W: 182 L: 77 D: 3

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 84b0aab..9ce95de 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -903,7 +903,8 @@ namespace {
     // Initialize score by reading the incrementally updated scores included in
     // the position object (material + piece square tables) and the material
     // imbalance. Score is computed internally from the white point of view.
-    Score score = pos.psq_score() + me->imbalance() + pos.this_thread()->contempt;
+    Score score = pos.captures_to_hand() ? pos.psq_score() / 2 : pos.psq_score();
+    score += me->imbalance() + pos.this_thread()->contempt;
 
     // Probe the pawn hash table
     pe = Pawns::probe(pos);