🐛 Avoid storing the same move duplicated in both killer moves (#458)

lynx-chess · Oct 24, 2023 · 09a9a89 · 09a9a89
1 parent 5ef074f
commit 09a9a89
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/Lynx/Search/NegaMax.cs b/src/Lynx/Search/NegaMax.cs
@@ -254,7 +254,7 @@ private int NegaMax(int depth, int ply, int alpha, int beta, bool isVerifyingNul
                 PrintMessage($"Pruning: {move} is enough");
 
                 // 🔍 Killer moves
-                if (!move.IsCapture() && move.PromotedPiece() == default)
+                if (!move.IsCapture() && move.PromotedPiece() == default && move != _killerMoves[0, ply])
                 {
                     _killerMoves[1, ply] = _killerMoves[0, ply];
                     _killerMoves[0, ply] = move;