Commonly Asked Questions – Rule 118b.
118b/3 A bowler is using the two-handed approach. The bowler’s dominate hand is the right hand. Can the bowler use the right hand for spares?
Yes, since both deliveries are with the same dominate hand, the bowler did not change delivery and, therefore, is not in violation of any USBC rules.
118b/4 A player started league bowling right-handed, but later decided to use a two-handed approach. Is this a change of delivery and in violation of Rule 118b?
No, as long as all deliveries are made with the right hand, this would not be a
violation of Rule 118b.
118b/5 What are the requirements of a delivery for a two-handed approach?
A two-handed bowler is required to use the same dominant hand during their delivery on both their first and second shots (this refers to the hand in which the bowling ball rests). They also have the option of utilizing a thumb hole or not—both are acceptable. However, only one set of gripping holes is allowed.