Constructed case: In a tournament (LoC Tournament Rules apply, no rapid, no blitz) White plays d7-d8Q by placing the new Queen on d8 with the right hand and removing the pawn d7 with the left. White did not press the clock but claimed a checkmate.

Relevant rules:

• 4.1 Each move must be played with one hand only.
• 5.1.1 The game is won by the player who has checkmated his opponent’s king. This immediately ends the game, provided that the move producing the checkmate position was in accordance with Article 3 and Articles 4.2 – 4.7.
• 6.2.1 During the game each player, having made his move on the chessboard, shall stop his own clock and start his opponent’s clock (that is to say, he shall press his clock). This “completes” the move. A move is also completed if:
  • 6.2.1.1 the move ends the game (see Articles 5.1.1, 5.2.1, 5.2.2, 9.6.1 and 9.6.2), or
  • 6.2.1.2 the player has made his next move, when his previous move was not completed.
• 7.5.4 If a player uses two hands to make a single move (for example in case of castling, capturing or promotion) and pressed the clock, it shall be considered and penalized as if an illegal move.

I discussed the case with some IA and FA. In our opinion, the checkmate and the result 1-0 stands. White did not press the clock, so 7.5.4 does not apply. To complete the move, it is not necessary to press the clock because the move ends the game (6.2.1.1). 5.1.1 allows a violation of 4.1 by not mentioning it.

We further think that that is not what was intended. We think that what was intended is

7.5.4 If a player uses two hands to make a single move (for example in case of castling, capturing or promotion) and completes the move, it shall be considered and penalized as if an illegal move.

Are we wrong with our decision? Is there a case illustrating that the formulation of 7.5.4 is according to it’s intention? Any other opinions?