This is a link to a website that discusses it

http://www.notedpokerauthority.com/q...frequency.html

& I copied and pasted this from my blog below that sort of explains it.

"At the start of the day I read up on Sklansky's optimal bluffing frequency. He says if your bluff % in a particular spot is the same as the pot odds you are laying your opponent to call your bluff then even if your opponent adjusts perfectly is at worst 0ev.

I'll try explain,

If I bet $10 into a $20 pot on the river when a flush card hits, I am giving my opponent 3-1 on his call. Now if I really have the hand 3/4 times but the 4th time I am bluffing my opponent is in a no win situation. If he calls each time he loses $10 the 3x I have the hand and makes $30 the one time I was bluffing (O). If he folds all the time he loses a $20 pot every 4th time where I was bluffing. "