From: Marco Costalba <mcostalba@gmail.com>
Date: Tue, 15 Sep 2009 05:47:27 +0000 (+0100)
Subject: Evaluation drift
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=c81010a8780d998d0d9a8bd28fd83402736f563b

Evaluation drift

Increase evaluation score with ply.

After 940 games at 1+0

Mod vs Orig +247 =487 -206  +15 ELO

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

diff --git a/src/search.cpp b/src/search.cpp
index b4c08373..39ed624c 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1543,7 +1543,11 @@ namespace {
         staticValue = tte->value();
     }
     else
+    {
         staticValue = evaluate(pos, ei, threadID);
+        if (!value_is_mate(staticValue + Value(ply)))
+            staticValue += Value(ply);
+    }
 
     if (ply == PLY_MAX - 1)
         return evaluate(pos, ei, threadID);