diff --git a/src/search.cpp b/src/search.cpp index 8da12118..97ed196a 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1148,7 +1148,8 @@ namespace { UndoInfo u; pos.do_null_move(u); - Value nullValue = -search(pos, ss, -(beta-1), depth-4*OnePly, ply+1, false, threadID); + int R = (depth > 7 ? 4 : 3); + Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID); pos.undo_null_move(u); if (nullValue >= beta)