From b9e3e7921b638109bd19395fd201f87c9110614a Mon Sep 17 00:00:00 2001
From: Taras Vuk <117687515+TarasVuk@users.noreply.github.com>
Date: Tue, 14 Oct 2025 21:16:34 +0200
Subject: [PATCH] Increase NMP reduction when improving

Passed STC:
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 52896 W: 13904 L: 13565 D: 25427
Ptnml(0-2): 186, 6022, 13706, 6335, 199
https://tests.stockfishchess.org/tests/view/68e67d02a017f472e763dfaf

Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 168354 W: 43750 L: 43163 D: 81441
Ptnml(0-2): 81, 18284, 46882, 18827, 103
https://tests.stockfishchess.org/tests/view/68e79d7ba017f472e763e352

closes https://github.com/official-stockfish/Stockfish/pull/6361

bench: 2537382
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index fa2355130..e6ee4274e 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -869,7 +869,7 @@ Value Search::Worker::search(
         assert((ss - 1)->currentMove != Move::null());
 
         // Null move dynamic reduction based on depth
-        Depth R = 6 + depth / 3;
+        Depth R = 6 + depth / 3 + improving;
 
         ss->currentMove                   = Move::null();
         ss->continuationHistory           = &continuationHistory[0][0][NO_PIECE][0];