question on head design - high/low spin

[RickinMA]

sorry if this is a stupid question - just trying to better understand how a particular driver head design could be lower spin or higher spin than another if each is made of similar materials, similar size, same loft, etc

for example,
1) Lyle just got WBL into a 10.3* DCT because it's a lower spinning head and the launch angle seems to be just right for him
2) Geek just released their FS2 which is supposedly like the Failsafe, but lower spin design....
3) other designs seem to be higher spin - the hi-bore for example generally plays like a higher loft - and the new wishon 919 seem to be putting people in lower lofts than "normal"

anyway, i'm not questioning that it exists, but what causes the differences in performance if the shafts are the same, the weights are the same, the materials are the same, etc - I can't see a bulge/roll difference in many of these clubs and most specs look the same

I suppose a change in center of gravity could change the way the club comes through the ball (like the hi-bore) but how is spin rate effected?

[Clugnut]

Certainly not a stupid question. I think I understand how it works, but would love to hear someone with more understanding explain it.

[warbirdlover]

LYLE!!! Where are ya Lyle???