Differential does not create a set amount of hook or type of hook. Differential lead to core instability which leads to more flare, those rings you get around your ball. The higher the differential, the higher the flare. The higher the flare, the earlier the ball will roll in general, because it has a fresh surface to roll over. When it has low flare, it rolls over the same oil rings or "nicks" the oil rings, getting the ball down the lane more. This is just in general, as their are so many more variables to put into consideration (i.e. mostly bowler related, the difference with a high flare peice in the hands of a 35* rotation slow stroker, 75 degree medium speed medium revs, and a high speed high revs 90 degree release is huge)
Remember, the order of importance for the variables that a ball possesses in terms of hookability is in my opinion:
1. bowler
2. coverstock prep (imo, try taking a 320 grit plastic on heavy oil, it will move)
3. coverstock composition
4. core numbers/shape
5. pin position from pap
6. mass bias (depending on the strength could be 6 or 7)
7. weight holes
8. pin height from grip center (some might argue this, but moving a pin up without changing distance from pap seems to make a difference for me)
9. Finger holes and thumb holes clipping the core, changing dynamics
10. Static weights
11. position of cg
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stanski
