Use a std::bitset for KPKBitbase

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 035dd40a5c7c17d4b92dd11a2ff35f8d1b709cbb..0eea4127f80a36955d652301d73882f64806eca2 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1115,7 +1115,7 @@ moves_loop: // When in check, search starts from here
       // Step 16. Reduced depth search (LMR, ~200 Elo). If the move fails high it will be
       // re-searched at full depth.
       if (    depth >= 3
-          &&  moveCount > 1 + 2 * rootNode
+          &&  moveCount > 1 + rootNode + (rootNode && bestValue < alpha)
           && (!rootNode || thisThread->best_move_count(move) == 0)
           && (  !captureOrPromotion
               || moveCountPruning
@@ -1186,6 +1186,10 @@ moves_loop: // When in check, search starts from here
               r -= ss->statScore / 16384;
           }
 
+          // Increase reduction for captures/promotions if late move and at low depth
+          else if (depth < 8 && moveCount > 2)
+              r++;
+
           Depth d = clamp(newDepth - r, 1, newDepth);
 
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);