Have an span of 5 and 5 1/8 using 1/8 rev 1/8 lat just not releasing as clean as I like 3/8 and 1/4 seems too much thinking about 0 and 0 to take some grab at the bottom of the swing need some in-put please.

Tried 0 and 0 two games last night felt ok will bowl at least 3 games today to get an better idea.

With that long of a span, you probably need more reverse rather than less . . but every hand is different so I can't say for sure.  Are you perchance double jointed?  If your span is the correct length, less pitch may actually work better, if you're stretched at all it will make it worse. 

Have an span of 5 and 5 1/8 using 1/8 rev 1/8 lat just not releasing as clean as I like 3/8 and 1/4 seems too much thinking about 0 and 0 to take some grab at the bottom of the swing need some in-put please.

Historical rule was longer spans need more reverse.  That is not entirely wrong, but many bowlers don't need reverse at all on a thumb.  I went from 1/4 reverse to 1/4 forward with a 4 7/8 span but also went from 1/4 tuck to 1/2 away on my fingers to foster a softer open handed release.  It didn't change my ability to clear the ball at all. 

There is a relationship between finger pitches and thumb pitches.  Historically, nobody went away on their fingers unless they had physical limitations. 

Bowled two games cleared the thumb well stayed with the shot longer with less grip pressure, that's with 0/0. Also used ball with 1/8 and 1/8 cleared a little sooner just a bit more rotation need more games to be sure which is best.  Also considering trying about an 1/8 forward later this summer.

I will agree that every hand is different. The reason I must bevel the front of the thumb hole is so my thumb PAD can clear properly. I have scar tissue on it that makes it thicker than the base of my thumb. It grabs enough to slam thumb nail against back of hole. I don't have to bevel nearly as much with more reverse pitch. And I never would have tried that much reverse without it being suggested by a Regional level bowler. He uses 1/2" reverse with similar span.

No not really!
 
I can't imagine anyone with a 5 inch span using 0 reverse!  I have not seen a thumb flexible enough for that....OH wait yes I have!  One!  And the fella's thumb calls for a later under and reverse but he went to lateral out, one of the few I have seen to bowl well where his anatomy does not call for this setup for his anatomy.

Re: Gizmo's comments I agree with many of them!  I know he has drilled a lot more balls than I have and creates great releases with his attention to detail.  I have watched his videos.

But on these two points I would like to file should I say exceptions.

1.  No bevel in a thumbhole.  There is some debate on this.  Many drillers say bevel is dependent on the amount of fatty skin between the index finger and thumb.  I am a big believer in this.  Knowing a driller that had none (no fatty tissue between his index finger and thumb) he drilled virtually no bevel for himself.   But added bevel to most of his clients balls.  I having a lot of tissue there use a medium to moderate amount of bevel.  I am a big proponent of the just right amount of bevel using the Mo Pinel bevel tips outlined in the Ballreviews reference section.  I rlayed this information in that particular section from Mo to the Compiler of this reference guide.  This amount of bevel can vary for a person based on how they set up their balls ie if they used a different thumb pitch and span to adjust their roll.  In addition the amount of bevel can be different on the front of the thumb versus the side using the Mo bevel tips.  A change in thumb pitch will often change the amounts of bevel added and where in order to continue to facilitate a butter feeling thumb release.

2.  As to the thumb straight under the thumb joint for a perfect fit when put on top of the ball fingers in the fingerholes.

I believe there are bowlers(I am one of them with a very flexible hand and fingers(still at my age).  Many ball drillers are surprised at my span but I have mentioned to some that when it looks correct (perfect really) as I go to throw the ball and the ball weight tranfers to my fingers my hand seems to lentghen or stretch even more making the back of my thumb catch against the back of my thumbhole.

Bottom line.

1.  I couldn't bowl without thumb bevel and neither do some of the best pro bowlers you've ever seen.
2.  Thumb bevel is a funttion of thumb anatomy and pitches in the ball and can be resolved through the Mo Pinel bevel tips in our reference section.
3.  Total span is a function of size of hand AND flexibility of the hand pad and fingers and may have to adjusted after watching the throw and release.

Regards,

Luckylefty

All I can tell you guy's is that last week I bowled horrible with an ball that had 3/8 rev and shot 570+ , had it slugged changed to 0/0 shot 215-242-220 same shot same house. But Gizmo is correct about the fact that 4 years ago I had at least 1/2 rev just have weak grip right now.