"mating material

In otb chess I understand that the rules are that it is a draw if you lose on time but your opponent does not have mating material.

That rule, however, assumes that you will help you opponent to mate you in every daft way possible.

What are the true combinations of pieces where my opponent can truly be said not to have mating material? e.g. if both sides only have one night then there is mating material as there is a position in which mate may be delived (very obviously not forced)

Originally posted by Habeascorp
In otb chess I understand that the rules are that it is a draw if you lose on time but your opponent does not have mating material.

That rule, however, assumes that you will help you opponent to mate you in every daft way possible.

What are the true combinations of pieces where my opponent can truly be said not to have mating material? e.g. if bo ...[text shortened]... mating material as there is a position in which mate may be delived (very obviously not forced)

http://www.e4ec.org/immr.html

There are different rules applied on different locations, but generally you have mating material if:

1) You have a pawn, Rook or Queen (does not matter what the rest of the board looks like)
2) You have a Knight or Bishop and the opponent has at least one piece left...

But it can be tricky, i.e. you and your opponent might both have a light-square Bishop. Thinking about it, there is no mating possibility for a lone Bishop vs. a lone Rook or lone Queen either! Same goes for N vs. Q...

On the Internet, generally all these possibilities are worked out dramatically badly. In real situations, well, it all comes down to who can argue the best 😉

PP's link shows that you may claim the draw based on structural grounds as well, but again, on an Internet blitz application this rule won't get you far 😀

I remember a bullet game against an FM (?) that had to end by the 50-move rule (not bad 50 premoves in the last 10 seconds), although the pawns made it a structural draw already (but it would not have been detected by the application, naturally, so we had to play on - or we could have just offered a draw of course, but in the heat of the battle we did not consider that possibility.)

edit: something like this

Thanks for that. Much more complex than one would imagine. I can now make a pain of myself done the local club adjudicating blitz matches.

Follow up question. There is a local (or maybe much wider) rule that my opponent may offer a draw and if I refuse I must be trying to win by "normal means". Any practical experience on this one given that in the starting position Black might not be able to force a win without bad moves by white, so is anything other than blatantly shuffling a remaining bishop evidence of not trying to win by normal means?