From: VoyagerOne <excelgeek@gmail.com>
Date: Sun, 9 Jun 2019 22:26:47 +0000 (-0400)
Subject: No DC prune in QS (#2185)
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=a9cca5c953e6ccec865102b13b47b9f45d98a0fc;p=stockfish

No DC prune in QS (#2185)

Don't prune discover checks in qSearch

STC:
LLR: 2.96 (-2.94,2.94) [0.50,4.50]
Total: 23176 W: 5320 L: 5039 D: 12817
http://tests.stockfishchess.org/tests/view/5cfbc9350ebc5925cf094ab3

LTC:
LLR: 2.95 (-2.94,2.94) [0.00,3.50]
Total: 128428 W: 22222 L: 21679 D: 84527
http://tests.stockfishchess.org/tests/view/5cfbf0b70ebc5925cf094ebc

Bench: 3883245
---

diff --git a/src/search.cpp b/src/search.cpp
index 0e10f44f..50bce13c 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1363,6 +1363,7 @@ moves_loop: // When in check, search starts from here
 
       // Don't search moves with negative SEE values
       if (  (!inCheck || evasionPrunable)
+          && (!givesCheck || !(pos.blockers_for_king(~pos.side_to_move()) & from_sq(move)))
           && !pos.see_ge(move))
           continue;