From 6b3eccea07c83110ec6c74fa5a9cc511b9637c5e Mon Sep 17 00:00:00 2001
From: PikaCat <Pika-Cat@qq.com>
Date: Tue, 23 Jul 2024 09:55:58 +0800
Subject: [PATCH] Revert "Allow ttValue in qsearch"

This reverts commit 3f8aa4a8bf770d8debb186802133855e161bc29f.

Since the clamping with probcutbeta, the position can now be found as a mate.
---
 src/search.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/search.cpp b/src/search.cpp
index a44b9ab0..af4c393a 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1401,7 +1401,7 @@ Value Search::Worker::qsearch(Position& pos, Stack* ss, Value alpha, Value beta,
               to_corrected_static_eval(unadjustedStaticEval, *thisThread, pos);
 
             // ttValue can be used as a better position evaluation (~13 Elo)
-            if (ttData.value != VALUE_NONE
+            if (std::abs(ttData.value) < VALUE_MATE_IN_MAX_PLY
                 && (ttData.bound & (ttData.value > bestValue ? BOUND_LOWER : BOUND_UPPER)))
                 bestValue = ttData.value;
         }