From 2ea323aec6a2c18f97c574efe2073a4ae185c7bd Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sat, 29 May 2010 10:01:25 +0100 Subject: [PATCH] Do IID also when we already have a ttMove In case tte->depth() is far lower the current depth and we are in a PV node. Almost 45% of researches give a different ttMove ! After 999 games at 1+0 Mod vs Orig +174 =694 -131 +15 ELO !!!!!!! Signed-off-by: Marco Costalba --- src/search.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index a76ff2ca..ba0a4f0c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1207,8 +1207,8 @@ namespace { } // Step 9. Internal iterative deepening - if ( depth >= IIDDepth[PvNode] - && ttMove == MOVE_NONE + if ( depth >= IIDDepth[PvNode] + && (ttMove == MOVE_NONE || (PvNode && tte->depth() <= depth - 4 * OnePly)) && (PvNode || (!isCheck && ss[ply].eval >= beta - IIDMargin))) { Depth d = (PvNode ? depth - 2 * OnePly : depth / 2); -- 2.39.2