From: VoyagerOne <excelgeek@gmail.com>
Date: Sun, 9 Jun 2019 12:27:50 +0000 (-0400)
Subject: SEE Pruning Tweak (#2183)
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=6ed81f09ffa513f0938c1a16fa4edd55e552c178

SEE Pruning Tweak (#2183)

Don't SEE prune any check extensions

STC (yellow):
LLR: -2.96 (-2.94,2.94) [0.50,4.50]
Total: 129934 W: 29390 L: 28905 D: 71639
http://tests.stockfishchess.org/tests/view/5cf6b1a70ebc5925cf08dedb

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 102115 W: 17692 L: 17224 D: 67199
http://tests.stockfishchess.org/tests/view/5cf830710ebc5925cf090331
---

diff --git a/src/search.cpp b/src/search.cpp
index 11586787..f26ab959 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -984,7 +984,8 @@ moves_loop: // When in check, search starts from here
               if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth)))
                   continue;
           }
-          else if (!pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo)
+          else if ((!givesCheck || !(pos.blockers_for_king(~us) & from_sq(move)))
+                  && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo)
                   continue;
       }