From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sun, 28 Jun 2020 15:23:29 +0000 (+0200)
Subject: Tweak futility pruning at parent node
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=53faad77071c5112ef12b2086fdea83b440cf55e;p=fairystockfish.git

Tweak futility pruning at parent node

3check STC
LLR: 2.97 (-2.94,2.94) [0.00,10.00]
Total: 3951 W: 1916 L: 1763 D: 272
http://www.variantfishtest.org:6543/tests/view/5eed14286e23db104fb88bee

3check LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 10074 W: 4762 L: 4523 D: 789
http://www.variantfishtest.org:6543/tests/view/5eefa6e56e23db104fb88c44
---

diff --git a/src/search.cpp b/src/search.cpp
index 09d01a9..c88632e 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1100,7 +1100,7 @@ moves_loop: // When in check, search starts from here
                   && !inCheck
                   && !(   pos.extinction_value() == -VALUE_MATE
                        && pos.extinction_piece_types().find(ALL_PIECES) == pos.extinction_piece_types().end())
-                  && ss->staticEval + 235 + 172 * lmrDepth <= alpha
+                  && ss->staticEval + (235 + 172 * lmrDepth) * (1 + pos.check_counting()) <= alpha
                   &&  thisThread->mainHistory[us][from_to(move)]
                     + (*contHist[0])[history_slot(movedPiece)][to_sq(move)]
                     + (*contHist[1])[history_slot(movedPiece)][to_sq(move)]