Successful bluffing is so incredibly situational it is probably not wise to try to assign mathematical ratios to it. It is much more on the psychology side of the game than on the numbers side. While we can say you should be raising about 15% of your hands preflop, we are able to say that because the math and combinatorics supports it - in other words the shuffled cards will present each player "raise worthy" hands about 15% of the time because over the long run that's just what happens with a 52 card deck. Same as we know you will get dealt AA every 221 hands, or .45% of the time. We can work that out because there are 4 aces in a 52 card deck and their are 6 different combinations in which to get those aces. In the long run the math will prevail.
Bluffing just doesn't work that way. It's all about your ability to convince your opponent that you have him beat based on the actions (line) you took leading up to the bluff. There can of course be math involved in leading up to your bluff attempt as you decipher what he might be holding (busted draw? has an ace? etc), but in the long run this is the psychology of the game.
Of course there is the old adage, if you aren't getting caught bluffing then you aren't doing it as often as you should.
__________________ "Most of the money you'll win at poker comes not from the brilliance of your own play, but from the ineptitude of your opponents. "
A good bluff is a good story told, if u set it up good the chance to bluff the guy/girl are good also, but if u check all the way to the river, and then decide to bluff at it, ull fail miserably, ouuu and u should not do it very often, coz no1 is that lucky in poker, sooner or later ull get caught, remember the bluff only works if u sell it good