From: lucasart <lucas.braesch@gmail.com>
Date: Sun, 28 Sep 2014 16:45:49 +0000 (+0100)
Subject: Clean up VALUE_KNOWN_WIN conditions
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=27a187729961fa9ad1910464556471bc7c8ce530;ds=sidebyside

Clean up VALUE_KNOWN_WIN conditions

A patch (+ some extra changes) passed with:

STC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 14575 W: 3101 L: 2967 D: 8507

LTC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 42579 W: 7580 L: 7496 D: 27503

Bench: 6545733

Resolves #52
---

diff --git a/src/search.cpp b/src/search.cpp
index 436b6438..fa92aa6f 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -545,8 +545,7 @@ namespace {
         && !ss->skipNullMove
         &&  depth < 7 * ONE_PLY
         &&  eval - futility_margin(depth) >= beta
-        &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
-        &&  abs(eval) < VALUE_KNOWN_WIN
+        &&  eval < VALUE_KNOWN_WIN  // Do not return unproven wins
         &&  pos.non_pawn_material(pos.side_to_move()))
         return eval - futility_margin(depth);
 
@@ -658,7 +657,6 @@ moves_loop: // When in check and at SpNode search starts from here
     singularExtensionNode =   !RootNode
                            && !SpNode
                            &&  depth >= 8 * ONE_PLY
-                           &&  abs(beta) < VALUE_KNOWN_WIN
                            &&  ttMove != MOVE_NONE
                        /*  &&  ttValue != VALUE_NONE Already implicit in the next condition */
                            &&  abs(ttValue) < VALUE_KNOWN_WIN