I use 1/2 reverse both fingers and feel i could upto 3/4 reverse in ring finger but shorted my span another 1/16 instead to keep nail from hitting front of grip. I also went to 1 1/4 clt drill and found with these changes it is alomost impossible to hang in the ball now at all. I have a much cleaner release and a ton of forward roll which for my game more up the boards is perfect. I also went 1/8 reverse and 1/8 left lateral with the thumb and again the feel for me is greater but ball comes off hand faster so i have to remember the open hand release or will grab at the bottom of swing and actually kill off the extra revs i gained from being cleaner.

Bill does not say much about finger pitches except that the should be adjusted shorter for more forward than 0 and longer for more reverse.

it is acknowledged that finger pitches were often used on the pro tour to decrease lift ane revs(reverse) and increase revs and lift(forward).
Now that many people are finding themselves somewhat inflexible they are using more pitches to get there fingers flat on the pad of the grip.

REcently I have tried a different set of thumb pitches, more forward with more reverse pitch.  I have seen a slight decrease in revs and lift and also a smoother breakpoint(something I need).  I have also tried this new thumb pitch with my old 0 to 1/32 forward finger pitch and am still assessing.

Flexibility is really the issue.  Customizing around your midpoint also changes reaction.  ie Mo Pinel will often add more forward in middle and some reverse in ring to increase axis tilt or the opposite to decrease axis tilt.

REgards,

Luckylefty