From 9fa258ee1d36d5a432a7a3e857e0723d439528b0 Mon Sep 17 00:00:00 2001
From: Dubslow <bunslow@gmail.com>
Date: Fri, 19 Aug 2022 22:49:29 -0500
Subject: [PATCH] Razor also on PV nodes

Simplification introduced by xoto10

blue LTC vs new master:
https://tests.stockfishchess.org/tests/view/631ad4ef9cfa5e9b648d1b4e
LLR: 2.93 (-2.94,2.94) <-1.75,0.25>
Total: 59184 W: 16002 L: 15828 D: 27354
Ptnml(0-2): 65, 5777, 17747, 5925, 78

blue STC vs old master:
https://tests.stockfishchess.org/tests/view/6306b87b902a848543334c25
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 213944 W: 57184 L: 57159 D: 99601
Ptnml(0-2): 877, 23448, 58331, 23405, 911

blue LTC vs old master:
https://tests.stockfishchess.org/tests/view/63070e6b902a8485433357e7
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 192080 W: 52050 L: 52006 D: 88024
Ptnml(0-2): 232, 18981, 57611, 18943, 273

closes https://github.com/official-stockfish/Stockfish/pull/4147

bench 4208975
---
 src/search.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/search.cpp b/src/search.cpp
index 162a0994..12576378 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -776,8 +776,7 @@ namespace {
     // Step 7. Razoring.
     // If eval is really low check with qsearch if it can exceed alpha, if it can't,
     // return a fail low.
-    if (   !PvNode
-        && depth <= 7
+    if (   depth <= 7
         && eval < alpha - 369 - 254 * depth * depth)
     {
         value = qsearch<NonPV>(pos, ss, alpha - 1, alpha);
-- 
2.39.2