From ade3bb9a4e774aa9b760235f3b0ee42e0a0420d9 Mon Sep 17 00:00:00 2001
From: ajithcj <achajo@yahoo.co.in>
Date: Fri, 24 Jun 2016 17:10:25 +0000
Subject: [PATCH 1/1] Use staticEval in null prune condition

Don't null prune at depth < 12 if staticEval < beta

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 62858 W: 12035 L: 11632 D: 39191

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 49784 W: 7009 L: 6720 D: 36055

bench: 8054611
---
 src/search.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/search.cpp b/src/search.cpp
index 064df0ca..97ab5918 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -731,6 +731,7 @@ namespace {
     if (   !PvNode
         &&  depth >= 2 * ONE_PLY
         &&  eval >= beta
+        && (ss->staticEval >= beta || depth >= 12 * ONE_PLY)
         &&  pos.non_pawn_material(pos.side_to_move()))
     {
         ss->currentMove = MOVE_NULL;
-- 
2.39.2