From: Marco Costalba <mcostalba@gmail.com>
Date: Mon, 5 Jan 2009 11:41:27 +0000 (+0100)
Subject: Take in account odd depths in razoring formula
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=dc4e2d8184f916e245a887a188fa0ccc6831c3d1;hp=e828753a3ad85c53cdeda61df428a6c73b715ff5

Take in account odd depths in razoring formula

This is somewhat taken from Stockfish 1.2 Default,
only the razoring thresold are updated, not the
razoring depth.

At the end razoring is a bit more aggressive. Results
seems slightly positive.

After 999 games +239 =536 -224 Elo +5

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

diff --git a/src/search.cpp b/src/search.cpp
index f7f62b23..45e0888d 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1247,8 +1247,8 @@ namespace {
     {
         Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
         if (   (v < beta - RazorMargin - RazorMargin / 4)
-            || (depth <= 2*OnePly && v < beta - RazorMargin)
-            || (depth <=   OnePly && v < beta - RazorMargin / 2))
+            || (depth < 3*OnePly && v < beta - RazorMargin)
+            || (depth < 2*OnePly && v < beta - RazorMargin / 2))
             return v;
     }