If you want to get rid of that late game sticking, open the thumb hole up a little more, 1/64" - 1/32", and use a Magic Carpet, as I mentioned earlier. The website is
www.bowl4fun.com
Contact Ron Clifton at the phone number on the website or by e-mail and he'll probably send you one for free, that's how he gets us hooked. Don't open the thumb hole up until you have the Magic Carpet in hand. While you're on the site look at the great information in his hints section. -- JohnP
1. I have same span, well, my cut is at 4 3/8 as the OP.
2. I have forward/side left thumb, reverse fingers
3. I switch from traditional thumb slug to Vise IT. (glad I did)
4. I use Magic Carpet for almost 10 years and I love it....but...
Right now, I'm trying to get used to not using magic carpet, I'm trying different tape combinations and it's not the same. Magic Carpet just allows for good timing and a more relaxed hand. Dan, give MC a try. Hopefully your PSO sells them, it's $2 each.
It sells for $20 for 10 and they go a long way. Now that I have the IT system, I'll have enough for a long while.