Maximum aspiration delta of 64

After 9242 games
Mod vs Orig: 1483 - 1373 - 6386  ELO +4 (+- 2.9)

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

diff --git a/src/search.cpp b/src/search.cpp
index 19e6c14b78e33ff34df72386999b92da27ff7a54..5196e86277880817d623b6c94645874d0ebe744e 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -657,7 +657,7 @@ namespace {
             int prevDelta1 = bestValues[iteration - 1] - bestValues[iteration - 2];
             int prevDelta2 = bestValues[iteration - 2] - bestValues[iteration - 3];
 
             int prevDelta1 = bestValues[iteration - 1] - bestValues[iteration - 2];
             int prevDelta2 = bestValues[iteration - 2] - bestValues[iteration - 3];
 

-            aspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16);
+            aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 64);

             aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize
 
             alpha = Max(bestValues[iteration - 1] - aspirationDelta, -VALUE_INFINITE);
             aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize
 
             alpha = Max(bestValues[iteration - 1] - aspirationDelta, -VALUE_INFINITE);