There are obvious ones that I know, like queen and rook (or either) vs lone king, and I also know you can't checkmate with only a bishop or knight, for instance.
But what if you have a rook and bishop vs a knight, is that possible? What if it's vs a knight but with eight pawns? I mean the list is endless. In short, I just want to know when it's a good idea just to say it's a draw vs other times you just keep trying and trying to get a checkmate. Thank you.