From ae9e55cf530081afea34216b86b6eb5d9b2b5661 Mon Sep 17 00:00:00 2001
From: Shawn Xu <xu107288696@gmail.com>
Date: Mon, 29 Jul 2024 00:04:03 -0700
Subject: [PATCH] Simplify Cutnode Reduction

Passed Non-regression STC:
LR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 143968 W: 37439 L: 37333 D: 69196
Ptnml(0-2): 521, 17228, 36456, 17182, 597
https://tests.stockfishchess.org/tests/view/66a73f9f4ff211be9d4ed27f

Passed Non-regression LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 198954 W: 50384 L: 50345 D: 98225
Ptnml(0-2): 201, 22360, 54347, 22337, 232
https://tests.stockfishchess.org/tests/view/66a906e94ff211be9d4ed423

closes https://github.com/official-stockfish/Stockfish/pull/5526

bench 1277466
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index beafd87dd5c..5f87f28fded 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1133,7 +1133,7 @@ Value Search::Worker::search(
 
         // Increase reduction for cut nodes (~4 Elo)
         if (cutNode)
-            r += 2 - (ttData.depth >= depth && ss->ttPv) + (!ss->ttPv && move != ttData.move);
+            r += 2 - (ttData.depth >= depth && ss->ttPv) + !ss->ttPv;
 
         // Increase reduction if ttMove is a capture (~3 Elo)
         if (ttCapture)