I used to bowl with a bent elbow, and my ball speed was slow as crap. I straightened out and got a lot more leverage. keep as straight as you can, yes it matters. You can't be 100% free with a bent arm. On your downswing your bicep always has to catch up. If you have a high backswing, bring down a tad, it won't hurt your ball speed.
BMM
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June 3, 2003 First 600 Series(208,258,170)!!!!!!