Calling on the river in Hold'em

[Shandrax]

Ok, same old topic...110th repetition.

We all know that there is an optimal bluffing and a corresponding calling frequency in poker.

It all started with 5 card Draw jacks or better. If a guy opened the pot with jacks or better you call with kings or better and if he keeps betting you call with a certain percentage of your hands. Obviously such a call on the river is rather easy, because you have at least kings = a made hand. So if game theory tells you to call 8 out of 9 times, you can simply lean back do it, because you know your kings will beat any busted hand.

Now how does this transform into Hold'em? You start with two hole cards and you only make a hand about 45% of the time. If you don't pair up you have at best a high card 55% of the time. If you are supposed to call 8 out of 9 times now, about 4 times you got pretty much nothing either, especially if you consider that a rather common "busted" hand is A-K.

What now?