Lane Inspection Procedures

Three-unit Lane Dressing Rule is Suspended By USBC Equipment Specifications Committee

ARLINGTON, Texas – After reviewing recent research on lane dressing and examining the current rules about how lane oil is applied, the United States Bowling Congress Equipment Specifications Committee determined the three-unit rule, required at the time oil is applied to a lane, no longer is applicable and will be suspended.

The USBC Equipment Specifications and Certifications team’s research has shown advancements in technology, including how today’s bowling balls drastically alter any oil pattern applied to a lane surface, have made the rule

Instituted by the American Bowling Congress in 1992, the three-unit rule states lane dressing could be applied in any amount and any distance, as long as there was a minimum of three units, and it became the only standard oil
pattern regulation.

The review of the three-unit rule is a continuation of the USBC’s commitment to continually explore all facets in bowling while thinking about the future of the sport.

“At this time, it makes sense to suspend the rule but continue to monitor leagues and competitions as the equipment we use, and the lanes on which we compete, continue to evolve,” USBC Equipment Specifications chair Andrew Cain said. “A review of the current lane-dressing regulation was simply the next logical phase of research and one within which the applicability of the three-unit rule itself was called into question. This process of constant inquiry and ensuing research is central to maintaining the integrity of our sport.”
With the suspension of the three-unit rule, local associations no longer will be required to submit an annual Lane Dressing Inspection Report (LDIR) for its centers.

The research performed at the International Training and Research Center in Arlington showed lane patterns are drastically altered by the use of today’s bowling balls, and most patterns likely do not comply with the three-unit
rule by the end of a league session.

USBC will continue to run Sport-compliant patterns for its national events, such as the USBC Open and Women’s Championships, the Junior Gold Championships and its major short-duration events. USBC also will maintain the Standard, Challenge and Sport lane conditions average conversion charts, for those who wish to compete in leagues and tournaments on challenging lane conditions.

The Equipment Specifications Committee also set the specification for any hole drilled in a bowling ball.

Effective Aug. 1, 2020, drilled holes cannot exceed a diameter of 1-9/16 inches and a hole cannot have a depth of more than 4-1/2 inches. The specification includes holes in which removable devices are used, though the holes size specifically was set to allow all existing removeable devises to remain.

Also, because any gripping hole that does not have the thumb or fingers inserted into it throughout the approach would be classified as a balance hole, which is not allowed as of Aug. 1, 2020, any secondary hole drilled inside of a gripping hole that is not intended for gripping purpose is considered a void and not allowed, except for vent holes. Visit for the drilling rule.

Go to for the report on the three-unit rule.