How much the ball wants to hook, 1 (straight, a spare ball) to 10 (the strongest oil-eaters). The maker publishes no number for this ball, so this is estimated from the coverstock, core, finish, and differential.
500/2000 Abralon Polished w/Powerhouse Factory Finish Polish. Skims the oil and saves its energy for the dry part of the lane: longer skid, later and sharper hook. Polished and pearl balls. Surface changes over games, and a pro shop can take any ball either way with a pad.