Past Research, Articles and Presentations

Research conducted by the United States Bowling Congress (USBC) Equipment Specifications staff showed environmental factors, especially temperature, can change the hardness measurement of bowling balls. Urethane shell balls are the most prone to variance, although reactive shell balls had variance as well.

USBC conducted a series of tests after a question was raised in the field related to approved urethane balls allegedly measuring below specification.

Click HERE for the Hardness Research Report published in 2019.

USBC took an additional step in February, testing the hardness of urethane balls being used at the 2020 U.S. Open. The goal of testing at the U.S. Open was to ensure all balls used in the competition met USBC specifications and to collect valid data.

Click HERE for the report of the bowling balls tested at the 2020 U.S. Open.

USBC continued its research of bowling ball hardness at the 2020 World Series of Bowling in advance of the 2020 USBC Masters. USBC felt it appropriate to not only continue to check the hardness of urethane balls, but also to investigate the hardness of used reactive balls.

USBC staff analyzed the research in order for the Equipment Specifications Committee to consider next steps.

Click HERE for the 2020 Hardness Research Report.

Since completion of the Ball Motion Study in 2008, USBC has stated that if factors were determined to have a high impact on ball motion, a specification would be developed if one was not in place. Conversely, if factors were determined to have a lesser impact on ball motion, further studies would be conducted to investigate if modifying or removing specifications relating to those elements needed to occur.     
Bowlers, pro shop operators, some manufacturers and much of the industry has expressed concerns that static weights are no longer relevant in today's world of high-performance bowling balls that are affected more by ball dynamics and cover stock chemistry. Many called for an increase in the maximum static weight allowance or an outright elimination of the USBC static weight specification altogether.

In response, the USBC began studying the degree to which static weights affect ball motion. This study - partially completed this past May 2011 - illustrated that if the current USBC static weight limits were eliminated or increased, the typical three-phase motion of bowling balls as they travel down a lane (skid, hook, then roll) would be significantly altered. A fourth phase of unpredictable motion begins to occur that would cause problems for bowlers and pro shop operators leading to an undesirable effect on the lanes.   

Click here to read about the results of the study. (PDF)   
Click here to view PowerPoint.  
The Equipment & Specifications Department within the United States Bowling Congress is responsible for setting and governing the specification limits of all equipment and machinery used in the sport. 
Recently, one of the department's objectives was defined as understanding which bowling ball properties affect ball motion and whether current or new specifications for bowling equipment need to be modified or developed. The full report of this research can be found by clicking on the link below.  

Ball Motion Study  (PDF)    
Critical Factors of Ball Motion (PDF)  

USBC clarifies intent on gripping layouts interpretation
May 26, 2016
USBC explains modification to new gripping layouts
May 10, 2016
USBC modifies rule on ball gripping holes
May 7, 2014
USBC retains static weight specification for bowling balls
July 6, 2011
USBC announces new verification requirements for pin manufacturers
March 2, 2010
Red, White and Blue Open results affirm equity of new oil patterns
December 17, 2009
USBC raises the allowable lower-limit radius of gyration (RG) measurement
August 30, 2009
New form will lead to accurate evaluation of arsenals, better understanding of ball motion
June 23, 2009
Understanding the USBC approval process
May 5, 2009
Communicating the Phases of Ball Motion | Video
April 1, 2009

New bowling ball specification will affect manufacturers, not bowlers
December 7, 2008
USBC begins research on bowling ball entry, exit angles
October 15, 2008
USBC's bowling ball research demonstrates world-class innovation
September 18, 2008
Bowling ball science on National Public Radio
May 17, 2008
USBC bowling ball motion study chosen for International Technical Conference
May 5, 2008
USBC bowling ball motion study concludes
April 1, 2008
USBC develops new biomechanics technology for bowling
March 13, 2008
USBC technology contest champion crowned
February 28, 2008
USBC proactive in facility, equipment standards group
January 11, 2008
Research complete on USBC bowling ball motion study
December 17, 2007
Lane Surface Task Force lays foundation for future research
December 1, 2007
USBC sets specification for lane oil viscosity
November 21, 2007
USBC forming Lane Conditioner/Cleaner Task Force
October 2, 2007
A statistical approach to lane center certification
August 30, 2007
USBC research uncovers new facts about bowling ball movement
August 22, 2007
Marketing vs Physics: The truth about axis migration and core dynamics
August 5, 2007
Center of Gravity (CG) placement on a symmetrical bowling ball: How critical is it?
July 31, 2007
USBC modifies lane dressing inspection requirements
July 13, 2007
USBC adopts lane hardness specification
June 5, 2007
Bowling ball performance and resulting ball life
May 22, 2007
High-tech device helps USBC advance pin testing
May 3, 2007
Understanding the relationship between core and cover stock properties
April 22, 2007
Core Properties
April 22, 2007
Calling all inventors: USBC seeks device measuring friction on bowling lanes
April 18, 2007
USBC leads the way in bowling technology
March 28, 2007
USBC chooses Ford engineer as technical advisor
February 28, 2007
USBC refocuses on System of Bowling research
June 23, 2006
USBC to revisit testing of bowling pins
January 27, 2006
USBC forms task force to address bowling ball issues
September 22, 2005
USBC changes CoR specification
February 24, 2005
USBC sets new new bowling ball specification
January 8, 2005


The science of bowling is one which, like any science, has its share of technical jargon—terms like "Coefficient of Friction," "Intermediate Differential," or "Symmetrical Core." Below we provide a comprehensive glossary of terms along with additional resources that will make the more technical side of bowling more accessible to you.

Updated Terminology
Static Weight Removal Chart
RG Differential Increase Chart