Does Chess.com use USCF or FIDE rules?

I'm asking this because there's a different rule for timeout vs. insufficient material on Chess.com and another site.

If memory serves, I believe Chess.com went with the USCF rule there because it is easier to implement.

Chess.com went with USCF because it is a United States site while lichess went for FIDE rules because it is French.

Oh ok, thanks.

Thanks.

This is the first thing I thought of, but since more than just people from the US play here I thought that probably wasn't it. But I guess it might be.

Just to confirm with other people, this is the position I was talking about:

Black flagged here. Would this be a draw by USCF rules by insufficient material, but a win for white by FIDE rules (due to a smothered mate)?

Under FIDE rules, you just have to be able to construct a mate (even if it is not forced) with the given pieces, so yes, Black flagging here would be a win for White under FIDE rules.  This is much more difficult to implement in software (and LiChess often has bugs related to this implementation), which is why chess.com went with USCF's rule which requires there to be a forcing line to get to mate (which White does not have, so it would be a draw).

I don't see the mating position here for white I don't think it is possible, right?

Well it's possible to happen but would never happen in a game picture like black pawn on h2 queen on h1 and king on h1 and if white king is on kf2 and bishop on d5 it would be mate

Oh yea you're right my bad

Yup np 

Another thing -- iirc, chess.com only considers sufficient material, so if it's forced mate with a king and knight vs king and pawn consider timing out, you will get the draw if my memory is correct