From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Mon, 23 Dec 2019 12:10:14 +0000 (+0100)
Subject: Increase aspiration window for drop variants
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=1f1dd40eb1bea190749ee4921851ddbc9192a78b;p=fairystockfish.git

Increase aspiration window for drop variants

crazyhouse STC (failed)
LLR: -2.97 (-2.94,2.94) [0.00,10.00]
Total: 3614 W: 1727 L: 1775 D: 112
http://www.variantfishtest.org:6543/tests/view/5deec1876e23db1ffe4a28be

crazyhouse LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 3726 W: 1863 L: 1711 D: 152
http://www.variantfishtest.org:6543/tests/view/5deeca6e6e23db1ffe4a28ca

crazyhouse VLTC
LLR: 2.96 (-2.94,2.94) [0.00,10.00]
Total: 11893 W: 5810 L: 5541 D: 542
http://www.variantfishtest.org:6543/tests/view/5df095f66e23db1ffe4a28d8
---

diff --git a/src/search.cpp b/src/search.cpp
index 1e8fc72..c49e4d8 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -432,7 +432,7 @@ void Thread::search() {
           if (rootDepth >= 4)
           {
               Value previousScore = rootMoves[pvIdx].previousScore;
-              delta = Value(21 + abs(previousScore) / 128);
+              delta = Value(21 * (1 + rootPos.captures_to_hand()) + abs(previousScore) / 128);
               alpha = std::max(previousScore - delta,-VALUE_INFINITE);
               beta  = std::min(previousScore + delta, VALUE_INFINITE);