From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sun, 7 Feb 2021 15:58:17 +0000 (+0100)
Subject: Reduce futility pruning depth for atomic
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=b73b2d3808f91a0469fda3f566b717fb22935c9e;p=fairystockfish.git

Reduce futility pruning depth for atomic

atomic STC
LLR: 2.98 (-2.94,2.94) [0.00,10.00]
Total: 6107 W: 2232 L: 2072 D: 1803
http://www.variantfishtest.org:6543/tests/view/601c7c016e23db669974e7da

atomic LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 2860 W: 987 L: 875 D: 998
http://www.variantfishtest.org:6543/tests/view/601e6e5a6e23db669974e803
---

diff --git a/src/search.cpp b/src/search.cpp
index 8b67407..5b581ef 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -909,7 +909,7 @@ namespace {
 
     // Step 7. Futility pruning: child node (~50 Elo)
     if (   !PvNode
-        &&  depth < 9
+        &&  depth < 9 - 3 * pos.blast_on_capture()
         &&  eval - futility_margin(depth, improving) * (1 + pos.check_counting() + 2 * pos.must_capture() + pos.extinction_single_piece() + !pos.checking_permitted()) >= beta
         &&  eval < VALUE_KNOWN_WIN) // Do not return unproven wins
         return eval;