I've also been looking for a formula to predict how a ball will play without going to the expense of having to map every ball I try.
I wasn't able to find one so have tried to work one out and have come up with this:
Take the distance rating minus half the spin rating to get a final rating:
For example lvl 81 ball is 5 and 4, take 2 from 5 to get an overall rating of 3.
The 87 ball is 5.6 and 5.2, again take 2.6 from 5.6 to get the same overall rating of 3.
I find these two balls play almost exactly the same with full backspin applied on all irons except my pitching wedge. The 87 plays a couple of yards shorter on the pitching wedge.
I'm reasoning that the extra distance of the 87 ball when playing a fullbackspin PW goes into height but spin remains high so it lands shorter.
I've tried the formula out on a couple of other balls. Srixon lvl 13 ball, distance 2.5 and spin 2..that comes out at 1.5, and the free ball which obviously has overall value of 0.
All fullbackspin shots.
Free ball..rating 0 PW 117, - 3i rated 225yds goes about 214
Lvl 13 ball..rating 1.5 PW 116, -3i 218
Lvl 81 ball..rating 3 PW 113, -3i 222/223
Lvl 87 ball...rating 3 PW 110/111, 3i 222/223
I can't get the lvl 93 ball yet but it's also comes out at 3 using this formula. If I'm right the PW should go 112 and the 3i 222/223.
I'd be interested if someone who uses that ball could tell me if I'm right or just talking rubbish lol.