# In chess, if a player ran out of time, how to determine if his/her opponent has the 'possibility of checkmating'?

From English Wikipedia, article 'Rules of chess':

If a player delivers a checkmate, the game is over and that player wins, no matter what is subsequently noticed about the time on the clock.

If player A calls attention to player B being out of time while player A is not out of time and some sequence of legal moves leads to B being checkmated then player A wins automatically.

If player A does not have the possibility of checkmating B then the game is a draw.

Can anyone provide a more detailed explanation what is 'possibility of checkmating' and who or what governs it? For example, I know that a king and a knight can checkmate a king with a rook. However, I don't think a king and a knight can checkmate a king with a queen. I didn't find a single checkmate position for that case (for weakest side, of course).

So, after exactly one of players had run out of time, who or what determines if his or her opponent has the possibility of giving a checkmate? I think it's quite essential because it means difference between a win and a draw.

• is this really rules for chess everywhere? or FIDE specifically? afaik USCF and FIDE have different rules
– BCLC
Commented Jan 5, 2022 at 14:30

If in doubt of being able to by player B, player A now plays both sides towards a checkmate of his choice.

In your example, player A would be able to prove it if he comes to the said checkmate somehow.

I think checkmating against King-Queen with King-Knight is impossible. The shown position (with the rook being switched to a queen) is no checkmate because the queen can just capture the knight.

• This sounds reasonable, but do you have any citation or other kinds of proof? When reading the question, I specifically wondered about whether "possible" meant "possible in any way", or "actually feasible", seeing as a player having only a Knight and King could feasibly win against an opponent with a full set of pieces only if that player suicided every single one (or placed them suboptimally). A player controlling both sides would mean "possible in any way", in which case it comes down to pretty much only the leftover pieces on the board in name, as well as the position of pawns, if any. Commented Dec 1, 2017 at 12:01
• Just look at the "rewritten" part one paragraph above: "and some sequence of legal moves leads to B being checkmated" Commented Dec 1, 2017 at 14:31
• Also "possible" in a rules set means "possible in any legal way" and as far as I know never "feasible". Rules have to be precise and if "feasible" is needed to be expressed...why write "possible" if you could just write "feasible"? Commented Dec 1, 2017 at 14:36
• is this really rules for chess everywhere? or FIDE specifically? afaik USCF and FIDE have different rules
– BCLC
Commented Jan 5, 2022 at 14:30

The current USCF rules specifically state (section 14E) that the following combinations are an enforceable draw (if not already in a win position) even when time runs out for the opponent, because the player has "insufficient material to win on time": Lone king; King and bishop; King and knight; King and two knights