Standardize stat penalty

STC:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 90631 W: 16325 L: 16323 D: 57983

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 97679 W: 12779 L: 12759 D: 72141

Bench: 6340591

Closes #1053

diff --git a/src/search.cpp b/src/search.cpp
index d555b62ee6289d534e822ace5e6f295602702eee..85817cd16f36c98183e57503a685215ded87feab 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -97,8 +97,8 @@ namespace {
     Move best = MOVE_NONE;
   };
 
-  // EasyMoveManager structure is used to detect an 'easy move'. When the PV is
-  // stable across multiple search iterations, we can quickly return the best move.
+  // EasyMoveManager structure is used to detect an 'easy move'. When the PV is stable
+  // across multiple search iterations, we can quickly return the best move.
   struct EasyMoveManager {
 
     void clear() {
@@ -635,7 +635,7 @@ namespace {
             // Penalty for a quiet ttMove that fails low
             else if (!pos.capture_or_promotion(ttMove))
             {
-                Value penalty = -stat_bonus(depth + ONE_PLY);
+                Value penalty = -stat_bonus(depth);
                 thisThread->history.update(pos.side_to_move(), ttMove, penalty);
                 update_cm_stats(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty);
             }