Mine is the Intense Inferno. I'm on my 3rd redrill. When I got it, I had read that the recommended drill was pin under ring finger, but having really slow ball speed, I thought I would be O.K. with my usual pin above. I couldn't carry--I'd leave a 10-pin, adjust and leave a 7-pin. Had I been bowling 9-pin no-tap, I would have had several 300's. So, I thought, maybe they were right and I had it re-drilled pin under ring finger. It hit like a marshmallow. So, it's back getting redrilled, 3 3/8 x 3 3/8. Usually, if I don't get along well with a ball, I just give it to my husband, but I really want this one to work.