Golf’s governing bodies announced a new local rule Tuesday that will reduce the maximum length of driver shafts from 48 to 46 inches.

The rule, which goes into effect Jan. 1, will allow the various tours the option to implement a local rule (MLR G-10) that will cap driver length at 46 inches.

This proposal was first announced in February and widely seen as a response to Bryson DeChambeau’s recent distance gains, though the USGA and R&A said that research into the topic first began in 2014. A proposal to limit the length of driver shafts was put forward in 2016 but shelved a year later once the governing bodies dove into the Distance Insights Project.

Though DeChambeau experimented with a 48-inch driver in the run-up to the 2020 Masters, he opted not to put the club in play and typically uses a 45 ¾-inch model.

Few pros, in fact, use a driver that exceeds 46 inches in length. One of the exceptions is Phil Mickelson, the reigning PGA champion, who recently railed against the governing bodies’ decision:

“We have taken time to consult fully with the golf industry, including players, the main professional tours and equipment manufacturers, and have considered their feedback carefully,” said R&A chief executive Martin Slumbers. “We believe this is the right thing for the game at this time and it will provide tournament organizers with the flexibility to choose for themselves within the framework of the rules.”

Added USGA CEO Mike Whan: “Admittedly, this is not the ‘answer’ to the overall distance debate/issue but rather a simple option for competitive events. It’s important to note that it is not a ‘Rule of Golf,’ and as such, it is not mandated for the average, recreational golfer. Rather, this is an available tool for those running competitive events.”

At the end of its release, the governing bodies said that research into golf-ball testing and tolerance of the spring-like effect is still under consideration.