Pot size on river?

If you´re heads-up on river but think your beaten, do you sometimes bet pot-sized?
I figure that if there is more than 50 % chance that your opp will fold, it´s a correct bet. Added to that your chance of winning if he calls.
So if you have a somewhat good read on what hand he has and how likely he is to call and you decide that he will fold or you will win a showdown in >50 % time - that is a correct bet, right? It would also probably mean that people would be afraid to call you to the river.

Am I right? Or is there a better way to bet?
This strategy is of course for the times when you think you are beaten but you think that your opponent thinks he´s beaten too.

Just a thought.

Very situation dependent.

For instance, can your hand only beat a bluff if called? This such situation would arise when you have AK unimproved on the river and think your opponent has you beat but won't call a pot-sized bet. In this case, it may be correct to make that bet if he will fold more than 1/2 the time, but this is complicated by the fact that sometimes when he folds your ace-king high was good.

On the other hand, if you have top pair with a rotten kicker on the river and suspect you're outkicked, it's quite different. In this case, there are hands that you have beat that could reasonably call your bet. Your read on your opponent (i.e. whether he will fold many hands that he could have that have you beat) and your betting position (i.e. if he checked into you or you're first to act) are criticial in this case.