spmcgivern there is a circumference rule, check it out!

In regard to the circumference rule, it doesn't apply to the bowlers drilled ball.

This was brought up and discussed long ago and the question posed to the USBC.

Question:

Does the rule for minimum ball size (8.500”) in the "Ball Manufacturing Specifications" (page:6 of the equip./Spec manual) and states "At time of manufacture, all balls must meet the following technical specifications"

Does it apply to a bowlers drilled ball?

Example:

Bowler has a older ball that do to shrinkage or resurfacing is below the min. of 8.5", Is it still legal for use?

or is there a rule regarding minimum size for a bowlers drilled ball?

(If so where do I find it in the rulebook/manual?)

If not, was there ever a rule? (I remember at one time they used min/max rings at the Nationals tournament to check ball size at check in)

Answer:

Thank you for your question.  Specifications for diameter (circumference) and roundness are manufacturing specifications only, they are not for the end user or the drilled ball.  In the example you provided, the smaller ball would still be allowed for use during USBC certified competition as long as it still had the required markings (Brand Name/Logo, Ball Name, Serial Number) so the ball can be identified.  For a long time there was size and roundness requirement on the drilled bowling balls at tournaments, but those specifications have since been removed.

Thank you,

Jason Milligan

Research Technician

Equipment Specifications & Certifications / Sport Bowling