Re-add lack of best move condition

lynx-chess · Oct 23, 2023 · 3f2d9fb · 3f2d9fb
1 parent 805b421
commit 3f2d9fb
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/Lynx/Search/NegaMax.cs b/src/Lynx/Search/NegaMax.cs
@@ -223,7 +223,8 @@ private int NegaMax(int depth, int ply, int alpha, int beta, bool isVerifyingNul
 
                 // 🔍 Principal Variation Search (PVS)
                 if (evaluation > alpha
-                    && reduction > 0)            // LMR failed)
+                    && reduction > 0            // LMR failed
+                    && bestMove is not null)
                 {
                     // Optimistic search, validating that the rest of the moves are worse than bestmove.
                     // It should produce more cutoffs and therefore be faster.