From 88a524c55244b3827747c0cb7c8de490b6119d23 Mon Sep 17 00:00:00 2001
From: Daniel Monroe <github.com@danielmonroe.net>
Date: Sun, 20 Apr 2025 14:29:29 -0700
Subject: [PATCH] Tweak futility formula

Passed STC
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 248448 W: 64344 L: 63718 D: 120386
Ptnml(0-2): 750, 29172, 63783, 29740, 779
https://tests.stockfishchess.org/tests/view/68056f5598cd372e3aea2901

Passed LTC
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 118824 W: 30358 L: 29874 D: 58592
Ptnml(0-2): 59, 12797, 33228, 13257, 71
https://tests.stockfishchess.org/tests/view/6805675698cd372e3aea20d0

closes https://github.com/official-stockfish/Stockfish/pull/6004

bench 1839796
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index 54d220cd1..b8a4b32a6 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1099,7 +1099,7 @@ moves_loop:  // When in check, search starts here
                 lmrDepth += history / 3593;
 
                 Value futilityValue = ss->staticEval + (bestMove ? 48 : 146) + 116 * lmrDepth
-                                    + 103 * (bestValue < ss->staticEval - 128);
+                                    + 103 * (bestValue < ss->staticEval - 128 && ss->staticEval > alpha - 50);
 
                 // Futility pruning: parent node
                 // (*Scaler): Generally, more frequent futility pruning