Widen the aspiration window for larger evals

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 8becdd3f827195cf4b44bea3ab6b01020b94a8fd..14de2377b142c06ead3aa642683f9de583586be2 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -380,7 +380,7 @@ void Thread::search() {
           if (rootDepth >= 4)
           {
               Value prev = rootMoves[pvIdx].previousScore;
-              delta = Value(17);
+              delta = Value(17) + int(prev) * prev / 16384;
               alpha = std::max(prev - delta,-VALUE_INFINITE);
               beta  = std::min(prev + delta, VALUE_INFINITE);
 
@@ -1210,8 +1210,7 @@ moves_loop: // When in check, search starts here
           // are really negative and movecount is low, we allow this move to be searched
           // deeper than the first move (this may lead to hidden double extensions).
           int deeper =   r >= -1             ? 0
-                       : moveCount <= 3      ? 2
-                       : moveCount <= 5      ? 1
+                       : moveCount <= 5      ? 2
                        : PvNode && depth > 6 ? 1
                        :                       0;