USBC 2020-2021 Rule Change
- Bowling Ball Altering Surface
- Effective August 1, 2019
While bowling in USBC competition, a bowling ball cannot:
a. Have the surface altered by the use of an abrasive.
b. Be cleaned with any liquid substance or cleaning agent.
c. Have any foreign material on it including, but not limited to, powder, rosin, marker or paint. All bowling balls so altered or cleaned must be removed from the competition.
Note: Should a foreign substance appear on the outer surface of a bowling ball which cannot be removed with a dry towel, an approved cleaner may be used with consent from a league or tournament officer.
Commonly Asked Questions
Rule 18. 18/1 When may I alter the surface of my bowling ball?
You are permitted to sand, polish, or clean the surface of your bowling ball prior to the start of competition. However, once tournament or league play begins, altering the surface of a bowling ball is strictly prohibited. This includes balls that have not yet been introduced into play.
18/2 When does competition start?
Competition starts once any bowler throws a ball for score in a league or tournament.
18/3 Can I pat my ball with rosin or powder if I wipe the ball before it is delivered?
No. Wiping the ball with a towel does not make the ball compliant to the rule. Patting a ball with a product is adding a foreign substance to the ball and cannot be done during competition. A product can only be applied to a bowler's hand and not leave residue on the surface of the ball.
18/4 Can I clean my ball with an approved cleaner during practice?
You can clean your ball with an approved cleaner during practice, unless otherwise specified by league or tournament rules.
18/5 If I take a ball out of my bag that I have not bowled with, can I clean it with an approved cleaner?
No, approved cleaners cannot be used once competition has begun. This rule applies to balls from a bowler's bowling bag, locker or car, etc. We suggest you clean all your bowling balls prior to the start of competition.
18/6 A tournament consists of doubles and singles events. The singles event is bowled first immediately followed by the doubles. Can I "alter the surface of" my bowling ball between events?
No. Rule 18 does not allow the outer surface of any bowling ball to be altered after the start of competition. Since the tournament is conducting singles and doubles concurrently, you cannot alter the surface of the bowling ball between events.
18/7 Can a bowler use an abrasive, cleaner or polish on just the track or only just a portion of the track of the ball?
No. USBC specifications require that the entire surface of the ball be prepared in a uniform manner. Preparing the surface of a ball in any other manner would be a violation of Rule 17a, Item 1. The penalty for a violation of this rule can include disqualification, forfeiture, removal from the league, and/or suspension of USBC membership.
18/8 What happens if a bowler uses a cleaner, abrasive, or puts a foreign substance on the ball? If the bowler was not aware of the rule, the ball is removed from competition. The bowler also should be given an explanation of the rule. Conversely, if the bowler knows a ball cannot be cleaned, patted with rosin or powder or use an abrasive, the ball must be removed from competition and the games are subject to forfeiture. If there is a question as to whether a bowler knew the rule or not, the league board of directors makes the determination. If the bowler refuses to remove the ball from competition, the games are subject to forfeiture.
18/9 If my ball comes back with residue on it and I cannot clean it with my dry towel, rag or shammy, can I use an approved cleaner?
Yes, provided you get permission from a league officer or tournament official. If you clean your ball without prior permission, you may be asked to remove the ball from competition, and/or the games may be subject to forfeiture.
18/10 When I have permission to clean my ball, may I clean the entire ball?
Yes, you may clean the entire surface of a bowling ball.
- Bowling Ball Weight Hole
- Effective August 1, 2020
Chapter 8: Equipment Specifications
7. Drilling Requirements.
All balls used in USBC certified competition must meet the following
1)Holes or indentations for gripping purposes
- i) Shall not exceed five and shall be limited to one for each finger and one for the thumb, all for the same hand.
- ii) Shall not exceed 1-9/16 inch diameter and 4-1/2 inch deep, including holes required to install removeable devices.
2) Any secondary hole drilled inside of a gripping hole that is not intended for gripping
purpose is considered a void and not allowed.
- iii) Must be used on every delivery.
3) No balance holes are allowed.
4) Balls without a thumbhole must have a scribed or engraved cross-hair lines ("+") near the
center of the palm to indicate the grip orientation. The ball must be delivered in the marked
orientation (i.e. palm must cover the "+").
5) One vent hole for each finger and/or thumb hole, not to exceed 1/4 inch in diameter is
6) One mill hole for inspection purposes not to exceed 5 .8 inch in diameter and 1.8 inch in
depth is permitted.
b. Balance. For balls weighing more than 10.00 pounds (all measurements are to be taken with
respect to the center of grip):
1) No more than 3 ounces of top/bottom weight, left/right weight and finger/thumb weight.
2) A ball used without any holes or indentations may not have more than three-ounce
difference between any two halves of the ball.
Commonly Asked Questions
Is a bowling ball with a thumb hole thrown by a no-thumb or two-handed bowler legal?
A bowler who doesn't use the thumb during a delivery cannot have a thumb hole, as it is considered a balance hole. If the ball does, it is illegal and games are subject to forfeiture. All holes drilled must be used for gripping purposes on every delivery.
Is a bowler allowed to not use the thumb hole on a first delivery but uses the thumb on
the second delivery with the same ball?
If a bowler uses a ball with a thumb hole that is not not used when making a delivery, the ball is illegal and games are subject to forfeiture. All holes drilled must be used for gripping
purposes on every delivery.
If the bowler covers the thumb hole with their palm, would that count as gripping?
No, the bowler is not gripping the ball if they are just covering the hole with their palm.
8. House Balls. House balls are exempt from item 7. House balls are defined as:
a. Being supplied by the center in which the certified competition is being used.
b. Having a polyester or basic urethane coverstock.
c. Having a differential RG less than 0.025 inches.
d. The ball is not drilled to fit the bowler specifically.
NOTE: A ball left in a bowling center by a bowler to be used as a house ball is not considered a house
9. Out of Specification.
If it is found that a bowling ball is or is suspected of being out of
specification, the bowler must be told by the tournament or league official to remove the ball from competition until it can be measured. If the ball is not removed or the bowler had prior knowledge of such, games are subject to forfeiture or disqualification. If the bowler had no prior knowledge,
the games would not be subject to forfeiture, but the ball would not be able to be used until it meets specifications.
Commonly Asked Question
Bowling Ball - Out of Specification
How is this rule enforced and what is the penalty for those who don't comply?
Once it is discovered that a bowler is using equipment which is not within specifications, the ball must be removed from competition and corrected before it can be used during certified competition. If the bowler uses a ball that is non-conforming with knowledge that it is out of specification, the scores are subject to forfeiture.