From: VoyagerOne <excelgeek@gmail.com>
Date: Sun, 12 Jun 2016 04:40:10 +0000 (-0400)
Subject: Simplify Check Extension
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=1c0c4db6775fae5a8b785630f4fd406c235880d9

Simplify Check Extension

STC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 32704 W: 6146 L: 6045 D: 20513

LTC:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 146622 W: 19967 L: 20017 D: 106638

Bench: 8245662
---

diff --git a/src/search.cpp b/src/search.cpp
index 0b4125fc..1db84c7e 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -873,9 +873,9 @@ moves_loop: // When in check search starts from here
                         && moveCount >= FutilityMoveCounts[improving][depth];
 
       // Step 12. Extend checks
-      if (   givesCheck
-          && (    moveCount == 1
-              || (!moveCountPruning && pos.see_sign(move) >= VALUE_ZERO)))
+      if (    givesCheck
+          && !moveCountPruning
+          &&  pos.see_sign(move) >= VALUE_ZERO)
           extension = ONE_PLY;
 
       // Singular extension search. If all moves but one fail low on a search of