From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Fri, 22 Feb 2019 20:05:59 +0000 (+0100)
Subject: Tweak NMP depth for racing kings
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=86b6b9ebccc41748d698370519c978b21667fef5;p=fairystockfish.git

Tweak NMP depth for racing kings

racingkings STC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 2269 W: 812 L: 706 D: 751
http://35.161.250.236:6543/tests/view/5c6daf426e23db07348e86e3

racingkings LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 3534 W: 1201 L: 1081 D: 1252
http://35.161.250.236:6543/tests/view/5c6dce286e23db07348e86ec
---

diff --git a/src/search.cpp b/src/search.cpp
index ac7eddf..9019f37 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -765,7 +765,7 @@ namespace {
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and value
-        Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
+        Depth R = ((823 - 150 * !pos.checking_permitted() + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         ss->currentMove = MOVE_NULL;
         ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();