You would think after 20 moves he would have accepted a draw. He must be waiting for you to resign so he can get a victory. That's taking the term die hard well beyond the limit.
game ending - 20 moves with no captures - and no victory in sight

If it truly is a draw, after 50 moves without a pawn move or a capture you should be able to claim a draw.
hi
i'm having a game with a guy rated just a 100 point more than me
in the game he still have both his bishops and i still have only one bishop
i offered him draw a long time ago, and i'm still trying to convince him it's a drawn game.
but still after 20 useless move he haven't admited it,
maybe if he was playing someone with a rating of 800 or a 1000 he could get a win , but not someone almost the same rating as him !!!
anyway i don't see an end to this game , i immobalised the king in a strategic position and now just moving the bishop, hopefully he'll see soon that there's nothing he can do !!
here's the game (warning : the last 20 moves are boring):
http://www.chess.com/echess/game.html?id=29417264