Simplify a depth condition

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 457580316694f238e42eb4b4763039dbbf1cef45..03d72b95373b412a543cf72641893817c5351348 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1037,7 +1037,7 @@ moves_loop: // When in check, search starts here
               lmrDepth = std::max(lmrDepth, 0);
 
               // Prune moves with negative SEE (~4 Elo)
-              if (!pos.see_ge(move, Value(-27 * lmrDepth * lmrDepth - 16 * lmrDepth)))
+              if (!pos.see_ge(move, Value(-31 * lmrDepth * lmrDepth)))
                   continue;
           }
       }
@@ -1099,7 +1099,7 @@ moves_loop: // When in check, search starts here
 
               // If we are on a cutNode, reduce it based on depth (negative extension) (~1 Elo)
               else if (cutNode)
-                  extension = depth > 8 && depth < 17 ? -3 : -1;
+                  extension = depth < 17 ? -3 : -1;
 
               // If the eval of ttMove is less than value, we reduce it (negative extension) (~1 Elo)
               else if (ttValue <= value)
@@ -1373,6 +1373,7 @@ moves_loop: // When in check, search starts here
     {
         int bonus = (depth > 5) + (PvNode || cutNode) + (bestValue < alpha - 113 * depth) + ((ss-1)->moveCount > 12);
         update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth) * bonus);
+        thisThread->mainHistory[~us][from_to((ss-1)->currentMove)] << stat_bonus(depth) * bonus / 2;
     }
 
     if (PvNode)
@@ -1495,7 +1496,7 @@ moves_loop: // When in check, search starts here
         if (bestValue > alpha)
             alpha = bestValue;
 
-        futilityBase = bestValue + 200;
+        futilityBase = std::min(ss->staticEval, bestValue) + 200;
     }
 
     const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory,