From fc41f64dfd8a61d0e275ddbecec292833458b86a Mon Sep 17 00:00:00 2001
From: cj5716 <125858804+cj5716@users.noreply.github.com>
Date: Tue, 13 Feb 2024 17:46:37 +0800
Subject: [PATCH] Simplify PV node reduction

Reduce less on PV nodes even with an upperbound TT entry.

Passed STC:
https://tests.stockfishchess.org/tests/view/65cb3a861d8e83c78bfd0497
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 118752 W: 30441 L: 30307 D: 58004
Ptnml(0-2): 476, 14179, 29921, 14335, 465

Passed LTC:
https://tests.stockfishchess.org/tests/view/65cd3b951d8e83c78bfd2b0d
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 155058 W: 38549 L: 38464 D: 78045
Ptnml(0-2): 85, 17521, 42219, 17632, 72

closes https://github.com/official-stockfish/Stockfish/pull/5057

Bench: 1303971
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index c407ae6ba6e..55a92947d32 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1111,7 +1111,7 @@ Value Search::Worker::search(
             r++;
 
         // Decrease reduction for PvNodes (~3 Elo)
-        if (PvNode && tte->bound() != BOUND_UPPER)
+        if (PvNode)
             r--;
 
         // Increase reduction on repetition (~1 Elo)