disable reverse futility pruning at PV nodes

brunocodutra · Nov 21, 2024 · a95d545 · a95d545
1 parent c777d95
commit a95d545
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/search/engine.rs b/lib/search/engine.rs
@@ -189,7 +189,7 @@ impl Engine {
 
         if alpha >= beta || ply >= Ply::MAX {
             return Ok(pv);
-        } else if pv.score() - self.rfp(depth, ply) >= beta {
+        } else if !is_pv && pv.score() - self.rfp(depth, ply) >= beta {
             #[cfg(not(test))]
             // The reverse futility pruning heuristic is not exact.
             return Ok(pv);