From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sat, 30 Jan 2021 22:45:01 +0000 (+0100)
Subject: Tweak probcut margin for extinction variants
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=7c94376bbae3f051daa5fc42bfb0f1a2ae533536;p=fairystockfish.git

Tweak probcut margin for extinction variants

shatranj STC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 1753 W: 212 L: 146 D: 1395
http://www.variantfishtest.org:6543/tests/view/601473246e23db669974e64a

shatranj LTC
LLR: 2.97 (-2.94,2.94) [-10.00,5.00]
Total: 2653 W: 205 L: 173 D: 2275
http://www.variantfishtest.org:6543/tests/view/60148af66e23db669974e65e

horde LTC
LLR: 2.96 (-2.94,2.94) [-10.00,5.00]
Total: 1249 W: 648 L: 589 D: 12
http://www.variantfishtest.org:6543/tests/view/60148b226e23db669974e660
---

diff --git a/src/search.cpp b/src/search.cpp
index 7dd9a69..943baf9 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -977,7 +977,7 @@ namespace {
         }
     }
 
-    probCutBeta = beta + (183 + 20 * !!pos.capture_the_flag_piece() + 50 * pos.captures_to_hand()) * (1 + pos.check_counting() + (pos.extinction_value() != VALUE_NONE)) - 49 * improving;
+    probCutBeta = beta + (183 + 20 * !!pos.capture_the_flag_piece() + 50 * pos.captures_to_hand()) * (1 + pos.check_counting() + pos.extinction_single_piece()) - 49 * improving;
 
     // Step 10. ProbCut (~10 Elo)
     // If we have a good enough capture and a reduced search returns a value