From a8cb002038bf314764a737077864a961c0e1d145 Mon Sep 17 00:00:00 2001
From: Michael Chaly <Vizvezdenec@gmail.com>
Date: Sat, 7 Sep 2024 18:46:09 +0300
Subject: [PATCH] Simplify ttmove reduction

Remove condition that clamps reductions for tt move.

Passed STC:
https://tests.stockfishchess.org/tests/view/66d5f1239de3e7f9b33d14b0
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 91136 W: 23805 L: 23646 D: 43685
Ptnml(0-2): 334, 10328, 24066, 10525, 315

Passed LTC:
https://tests.stockfishchess.org/tests/view/66d7c5889de3e7f9b33d1721
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 139242 W: 35130 L: 35030 D: 69082
Ptnml(0-2): 78, 15200, 38986, 15258, 99

closes https://github.com/official-stockfish/Stockfish/pull/5574

Bench: 1268715
---
 src/search.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/search.cpp b/src/search.cpp
index aab5c743cc5..1ed849f2a34 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1148,10 +1148,9 @@ Value Search::Worker::search(
         if ((ss + 1)->cutoffCnt > 3)
             r += 1 + allNode;
 
-        // For first picked move (ttMove) reduce reduction, but never allow
-        // reduction to go below 0 (~3 Elo)
+        // For first picked move (ttMove) reduce reduction (~3 Elo)
         else if (move == ttData.move)
-            r = std::max(0, r - 2);
+            r -= 2;
 
         ss->statScore = 2 * thisThread->mainHistory[us][move.from_to()]
                       + (*contHist[0])[movedPiece][move.to_sq()]