From: Marco Costalba <mcostalba@gmail.com>
Date: Wed, 18 Nov 2009 08:30:02 +0000 (+0100)
Subject: In razor qsearch use corrected beta
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=989833205fb63de094c1f28e1c5f803bc8a917e4

In razor qsearch use corrected beta

Correct beta by razor margin when callin qsearch

After 1019 games on Joona's QUAD

Mod - Orig: 524 - 495 (+10 elo)

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---

diff --git a/src/search.cpp b/src/search.cpp
index e0252932..76a88643 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1360,8 +1360,9 @@ namespace {
              && ttMove == MOVE_NONE
              && !pos.has_pawn_on_7th(pos.side_to_move()))
     {
-        Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
-        if (v < beta - RazorMargins[int(depth) - 2])
+        Value rbeta = beta - RazorMargins[int(depth) - 2];
+        Value v = qsearch(pos, ss, rbeta-1, rbeta, Depth(0), ply, threadID);
+        if (v < rbeta)
           return v;
     }