From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sat, 29 Sep 2018 22:33:18 +0000 (+0200)
Subject: Skip razoring for antichess variants
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=f69cc1c6d51ddca77eb0998caceec06a0ba4af22;p=fairystockfish.git

Skip razoring for antichess variants

STC giveaway
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 6849 W: 2738 L: 2561 D: 1550
http://35.161.250.236:6543/tests/view/5b9bedb66e23db0fbab0dd7a

STC losers
LLR: -2.98 (-2.94,2.94) [-10.00,5.00]
Total: 1882 W: 805 L: 881 D: 196
http://35.161.250.236:6543/tests/view/5babd6496e23db0fbab0dddf

LTC losers
LLR: 2.98 (-2.94,2.94) [-10.00,5.00]
Total: 1095 W: 510 L: 456 D: 129
http://35.161.250.236:6543/tests/view/5bad0b6f6e23db0fbab0dde2
---

diff --git a/src/search.cpp b/src/search.cpp
index 278e296..acc23ca 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -723,6 +723,7 @@ namespace {
     // Step 7. Razoring (~2 Elo)
     if (  !PvNode
         && depth < 3 * ONE_PLY
+        && !pos.must_capture()
         && !pos.capture_the_flag_piece()
         && !pos.max_check_count()
         && eval <= alpha - RazorMargin[depth / ONE_PLY])