Tweak history initialization

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 46463b327e12ea3f43bfbeb0de9eef5604fc4130..3c2ae3e52df8b0c43f8cc05a132c2adb801bef81 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -787,9 +787,9 @@ namespace {
     // The depth condition is important for mate finding.
     if (   !ss->ttPv
         &&  depth < 8
-        &&  eval - futility_margin(depth, improving) - (ss-1)->statScore / 301 >= beta
+        &&  eval - futility_margin(depth, improving) - (ss-1)->statScore / 303 >= beta
         &&  eval >= beta
-        &&  eval < 28692) // larger than VALUE_KNOWN_WIN, but smaller than TB wins
+        &&  eval < 28031) // larger than VALUE_KNOWN_WIN, but smaller than TB wins
         return eval;
 
     // Step 9. Null move search with verification search (~22 Elo)
@@ -1002,8 +1002,7 @@ moves_loop: // When in check, search starts here
               || givesCheck)
           {
               // Futility pruning for captures (~0 Elo)
-              if (   !pos.empty(to_sq(move))
-                  && !givesCheck
+              if (   !givesCheck
                   && !PvNode
                   && lmrDepth < 7
                   && !ss->inCheck
@@ -1179,7 +1178,7 @@ moves_loop: // When in check, search starts here
                          - 4433;
 
           // Decrease/increase reduction for moves with a good/bad history (~30 Elo)
-          r -= (ss->statScore + 5 * alpha) / 15448;
+          r -= ss->statScore / 13628;
 
           // In general we want to cap the LMR depth search at newDepth, but when
           // reduction is negative, we allow this move a limited search extension
@@ -1550,8 +1549,8 @@ moves_loop: // When in check, search starts here
       // Continuation history based pruning (~2 Elo)
       if (   !capture
           && bestValue > VALUE_TB_LOSS_IN_MAX_PLY
-          && (*contHist[0])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold
-          && (*contHist[1])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold)
+          && (*contHist[0])[pos.moved_piece(move)][to_sq(move)] < 0
+          && (*contHist[1])[pos.moved_piece(move)][to_sq(move)] < 0)
           continue;
 
       // movecount pruning for quiet check evasions