can someone please explain to me what the advantages are if u have a 9 tooth driver or a 10 tooth driver. which is better for acceleration, which is better for top end.

10 tooth drivers provide less rolling resistance for the track. But, you also usually need to do a D&R to net the full advantage of 10 tooth drivers. If not, your track to bulkhead clearance becomes smaller and may do more harm than good (snow clearance)

Puppy just like NorthernRMK touched on the 10 tooth drivers allow the track to bend around the driver more efficiently. Just like oversized rear idlers. Same principal. This does however change your overall gear ratio. Generally one would have to change the gearing in the chaincase to match the 10 tooth drivers. On top of that the chaincase should be rolled if track to tunnel clearance is an issue.