From 731ad9bbc3332cb7c73ef9aa8797e38c9deee452 Mon Sep 17 00:00:00 2001
From: Arseniy Surkov <93079612+codedeliveryservice@users.noreply.github.com>
Date: Fri, 29 Aug 2025 04:12:23 +0300
Subject: [PATCH] Simplify `adjust_key50` template

Remove the AfterMove template from the adjust_key50 function, which is only ever called with false.

closes https://github.com/official-stockfish/Stockfish/pull/6278

No functional change
---
 AUTHORS        | 1 +
 src/position.h | 8 +++-----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/AUTHORS b/AUTHORS
index 804824d8c..6bd323d2c 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -32,6 +32,7 @@ Antoine Champion (antoinechampion)
 Aram Tumanian (atumanian)
 Arjun Temurnikar
 Aron Petkovski (fury)
+Arseniy Surkov (codedeliveryservice)
 Artem Solopiy (EntityFX)
 Auguste Pop
 Balazs Szilagyi
diff --git a/src/position.h b/src/position.h
index 56bb7b5a4..dde496fe0 100644
--- a/src/position.h
+++ b/src/position.h
@@ -183,8 +183,7 @@ class Position {
                      Square&           rfrom,
                      Square&           rto,
                      DirtyPiece* const dp = nullptr);
-    template<bool AfterMove>
-    Key adjust_key50(Key k) const;
+    Key  adjust_key50(Key k) const;
 
     // Data members
     Piece      board[SQUARE_NB];
@@ -283,11 +282,10 @@ inline Bitboard Position::pinners(Color c) const { return st->pinners[c]; }
 
 inline Bitboard Position::check_squares(PieceType pt) const { return st->checkSquares[pt]; }
 
-inline Key Position::key() const { return adjust_key50<false>(st->key); }
+inline Key Position::key() const { return adjust_key50(st->key); }
 
-template<bool AfterMove>
 inline Key Position::adjust_key50(Key k) const {
-    return st->rule50 < 14 - AfterMove ? k : k ^ make_key((st->rule50 - (14 - AfterMove)) / 8);
+    return st->rule50 < 14 ? k : k ^ make_key((st->rule50 - 14) / 8);
 }
 
 inline Key Position::pawn_key() const { return st->pawnKey; }