diff --git a/src/search.cpp b/src/search.cpp index 693bea94..a97d3e02 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1237,7 +1237,7 @@ namespace { // Step 9. Internal iterative deepening if ( depth >= IIDDepth[PvNode] - && (ttMove == MOVE_NONE || (PvNode && tte->depth() <= depth - 4 * OnePly)) + && ttMove == MOVE_NONE && (PvNode || (!isCheck && ss->eval >= beta - IIDMargin))) { Depth d = (PvNode ? depth - 2 * OnePly : depth / 2);