Widen the aspiration window for larger evals

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 36329f8fe4205066f168f04c7e88cb084d36923d..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);