Quote Originally Posted by Chopper
i am just confused as to why we only call the river? if we feel we are ahead, why not raise it up? if villain folds, who cares? we get the $25. if he calls, we maximize this hand.
Maybe it becomes clearer if you would make a distinction between his betting-range and his calling-a-river-raise-range. There are situations were you are ahead of the first and behind the last, then raising is no good, but calling is.

And what drmcboy said.