List of Illegal Golf Club Drivers
The U.S. Golf Association (USGA) publishes a list every week of drivers that can be used for legal play. This list features clubs that do not violate established rules for flexibility in the driver head. The USGA refers to these drivers as conforming--they do meet testing standards established by the USGA in 1998 and revised in 2004. Any driver that does not meet these standards are referred to as nonconforming and are inelligible for use in any competition that conforms to USGA rules.
Imagine swinging a driver that gives your swing an added kick with a flexible head. The pop gives you greater distance with a shot, much like a hollow bat gives a baseball player the ability to hit a home run. Drivers that are not legal allow a spring action when hitting the ball. The USGA calls this spring measurement the coefficient of restitution (COR). The USGA measures COR with a test that measures the amount of bounce off the clubhead.
Not Legal for Official Play
Non-conforming drivers cannot be used during any sanctioned event on the PGA, LPGA, Nationwide or Champions Tour. In addition, the American Junior Golf Association follows guidelines and rules identical to the USGA regarding non-legal golf clubs. Rules prevent the use of these drivers at any USGA-governed event--the penalty for using a non-conforming club is disqualification. The USGA only evaluates clubs for tournaments in the United States. The Royal and Ancient Golf Club of St. Andrews has been following the same procedures for conformity as the USGA since the revamping of the Rules of Gulf in 2008.
The USGA publishes a list updated every Monday. It contains club names and manufacturers as well as identifying marks on the club itself and contains pictures of each to help users identify non-conforming clubs. Please note this list applies only to clubs used in events played by USGA rules. See additional resources for the USGA listing of legal golf clubs.