Ok what is the underlying concept here
So lets say you get to the river on some hand with some board and you decide to overbet twice the pot as a bluff. Now, if you decide to do this, you have to win the hand 2 out of 3 times to break even. Otherwise, you have made a mistake (in a vaccuum)
But looking at the other players perspective, he's faced with a 2 times the pot overbet and he has a bluff catcher. This bluffcatcher always beats a bluff from his opponent Now, he is calling a 2x pot bet to win 5x the pot. This means he has to be right 40% of the time for calling to be a breakeven play.
Now my question is, why isn't it 1/3 of the time? Is it just because when calling your considering a range and with the betting you are considering only with a bluff? What concept fills in this gap?