From 36c381154bcfb23b1ba9f1178c9eb9232099b821 Mon Sep 17 00:00:00 2001
From: Mysseno <jonoface@live.com.au>
Date: Fri, 14 Mar 2014 21:00:50 +1100
Subject: [PATCH] Depth dependant aspiration window delta

Split delta value in aspiration window so that when
search depth is less than 24 a smaller delta value
is used. The idea is that the search is likely to
be more accurate at lower depths and so we can exclude
more possibilities, 25% to be exact.

Passed STC
LLR: 2.96 (-2.94, 2.94) [-1.50, 4.50]
Total: 20430 W: 3775 L: 3618 D: 13037

And LTC
LLR: 2.96 (-2.94, 2.94) [0.00, 6.00]
Total: 5032 W: 839 L: 715 D: 3478

Bench: 7451319
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index d7a8379a..421d95fe 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -327,7 +327,7 @@ namespace {
             // Reset aspiration window starting size
             if (depth >= 5)
             {
-                delta = Value(16);
+                delta = Value(depth > 23 ? 16 : 12);
                 alpha = std::max(RootMoves[PVIdx].prevScore - delta,-VALUE_INFINITE);
                 beta  = std::min(RootMoves[PVIdx].prevScore + delta, VALUE_INFINITE);
             }
-- 
2.39.2