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

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;
     }