"... on the river, I bet and fold to a raise..."

[fretelöo]

This is a comment one hears quite often. The point is, I guess, that you're betting for value every time someone just calls, you're "bluffing" if everyone folds and you "gain information" and "save a bet" when you fold to the raise.

Of course, this is _almost_ pointless to discuss without a few concrete examples, but in all generality, you voluntarily put in a bet on the river, getting 1:x odds and are unwilling to call one more bet getting even better odds.
This can only be optimal, if people just don't c/r you on the river with hands that you beat.

And did anyone actually check whether this is true over a large sample? I.e., compared the return of just c/c or b/c the river instead of b/f?