Ric,
You and I have talked about this a bit in the past.
I have found that the heavy rolling low rg balls, work great on league heavy oil(where there is dry to the outside of the shot). The reason they work great is because the low rg and heavily loaded coverstock give the ball a tendancy to work and start hooking even in the heads and midlane. This allows the ball to be swung from the inside oil out to the dry and then the dry kicks the ball back to the pocket. Balls like the Mayhem, Reaction Roll, AMF Evo Tour, Phenom and Throttle all fit this bill great!
However on tournament oil. ie long deep and OB outside of 10. I have found higher rg, whether sanded or not works great. One of my best balls was a polished Demolition Zone. I've also done well on shots like this with a shiny pearl Brunswick Battle Zone Bullet!
As you and I discussed this different oil shot, any swing(which low rg balls force one to do, does not allow the recovery on this shot once one aims even the least bit away from the pocket!!! As there is no dry to the sides but only at the end of the pattern. Therefore the key to this shot is to find a ball that allows one to point at the pocket. I often find a 8 at the arrows to 11 line at the breakpoint works real nice for me on this really tough shot!
After I find the ball that allows me to point, balls I've very successfully used have been my Demo Zone, BZ Bullet and also like you the trusty Track Spell(mine is at 1000 grit sheen). All medium to high rg. I then just fit the backend to the shot. If I can pick a correct backend for the condition and point(all high rg balls lead to a point more easily) plus slow my speed down to about 12 mph while still acceleratingsmoothly thru release. Then many are in trouble.
REgards,
Luckylefty