From b73ae56ee18fd995b7071745eb3a3a4c2be57916 Mon Sep 17 00:00:00 2001
From: lucasart <lucas.braesch@gmail.com>
Date: Mon, 5 Jan 2015 22:09:12 +0000
Subject: [PATCH] Tune null search reduction

STC

LLR: 2.96 (-2.94,2.94) [-0.50,4.50]
Total: 107289 W: 21851 L: 21325 D: 64113

LTC

LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 83837 W: 14378 L: 13916 D: 55543

Bench: 7604776

Resolves #194
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index 86c572b4..587506ec 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -650,7 +650,7 @@ namespace {
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and value
-        Depth R = (3 + depth / 4 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
+        Depth R = ((823 + 67 * depth) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         pos.do_null_move(st);
         (ss+1)->skipEarlyPruning = true;
-- 
2.39.2