From 303fe9a1643b40a667923cba122e36beffde288c Mon Sep 17 00:00:00 2001
From: Stockfisher69 <stockfisher69@gmail.com>
Date: Sat, 2 Aug 2025 23:01:50 +0200
Subject: [PATCH] Simplification: Futility pruning for captures

tested in final form as simplication

passed LTC:
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 113682 W: 29199 L: 29074 D: 55409
Ptnml(0-2): 68, 12359, 31859, 12490, 65
https://tests.stockfishchess.org/tests/view/688e85a17d68fe4f7f130e24

earlier test, equivalent:
passed STC:
LLR: 2.96 (-2.94,2.94) <0.00,2.00>
Total: 120224 W: 31621 L: 31176 D: 57427
Ptnml(0-2): 415, 14167, 30567, 14484, 479
https://tests.stockfishchess.org/tests/view/68888bdd7b562f5f7b732643

closes https://github.com/official-stockfish/Stockfish/pull/6209

Bench: 2661621
---
 AUTHORS        | 1 +
 src/search.cpp | 7 ++++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/AUTHORS b/AUTHORS
index 6bf0745ad..e606e5a8d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -233,6 +233,7 @@ Stefano Di Martino (StefanoD)
 Steinar Gunderson (sesse)
 Stéphane Nicolet (snicolet)
 Stephen Touset (stouset)
+Stockfisher69
 Styx (styxdoto)
 Syine Mineta (MinetaS)
 Taras Vuk (TarasVuk)
diff --git a/src/search.cpp b/src/search.cpp
index 39d9862be..b807ae7d1 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1039,9 +1039,10 @@ moves_loop:  // When in check, search starts here
                 // Futility pruning for captures
                 if (!givesCheck && lmrDepth < 7 && !ss->inCheck)
                 {
-                    Value futilityValue = ss->staticEval + 225 + 220 * lmrDepth
-                                        + 275 * (move.to_sq() == prevSq) + PieceValue[capturedPiece]
-                                        + 131 * captHist / 1024;
+
+                    Value futilityValue = ss->staticEval + 232 + 224 * lmrDepth
+                                        + PieceValue[capturedPiece] + 131 * captHist / 1024;
+
                     if (futilityValue <= alpha)
                         continue;
                 }