From: Marco Costalba <mcostalba@gmail.com>
Date: Wed, 24 Dec 2008 08:34:09 +0000 (+0100)
Subject: Futility pruning till ply 6 included
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=2feb9d5100038038b371c91562bbf5342a815c39

Futility pruning till ply 6 included

Seems good:

After 796 games: +211 = 393 -192 +8 elo

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

diff --git a/src/search.cpp b/src/search.cpp
index a4ce7eff..768a22a4 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1314,12 +1314,14 @@ namespace {
               continue;
 
           // Value based pruning
-          if (depth < 6 * OnePly && approximateEval < beta)
+          if (depth < 7 * OnePly && approximateEval < beta)
           {
               if (futilityValue == VALUE_NONE)
                   futilityValue =  evaluate(pos, ei, threadID)
-                                + (depth < 2 * OnePly ? FutilityMargin1
-                                                      : FutilityMargin2 + (depth - 2*OnePly) * 32);
+                                + (depth < 2 * OnePly ? FutilityMargin1 :
+                                + (depth < 6 * OnePly ? FutilityMargin2 + (depth - 2*OnePly) * 32
+                                                      : FutilityMargin2 + (depth - 2*OnePly) * 64));
+
               if (futilityValue < beta)
               {
                   if (futilityValue > bestValue)