I throw a plastic ball at all of my ten pins, and if you watch the pros, they use a plastic ball on most spares. The left side, 4 & 7 pins, are my weakness in using my plastic ball, so for now I've been using my strike ball, but I plan on working om my problem over the summer. To each his own, what ever works for you, & is comfortable to you.
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I Absolutely LOVE my Ultimate Inferno, but Ultimately I LOVE my Absolute Inferno!
Bowling is more fun when you only have to throw 1 ball..........F*#k the 10 pin!!