Bryson DeChambeau caught the attention of lots of golf fans at the 2018 Travelers Championship when CBS cameras showed the two-time winner using a compass on his green book. Eventually, DeChambeau explained why he was using a compass, doing so to accurately map the PGA Tour's hole locations on to his green book to help him read the greens and chip shots.
However, DeChambeau also finally caught the attention of PGA Tour rules officials, curious if what the SMU product has been doing throughout the season is, in fact, illegal and against the Rules of Golf.
The PGA Tour is working with the USGA to investigate the matter, in part, because the Rules of Golf aren't clear on the subject.
Rule 14-3 of the Rules of Golf say a player may not "use any artificial device or unusual equipment, or use any equipment in an abnormal manner." However, players have been able to use the other kind of compass -- the one which shows direction -- in competition. That's because it doesn't tell the wind velocity or direction. A player still has to discern that.
The Rules of Golf, though, do prohibit golfers from using unapproved distance-measuring devices, and a compass could be construed as such.
The Rule is more explicit in the explanation of what is or isn't allowed, saying an object or device is illegal if used in such a way:
a. That might assist him in making a stroke or in his play;
or b. For the purpose of gauging or measuring distance or conditions that might affect his play;
or c. That might assist him in gripping the club, except that:
(i) gloves may be worn provided that they are plain gloves;
(ii) resin, powder and drying or moisturizing agents may be used;
and (iii) a towel or handkerchief may be wrapped around the grip
Under a pretty basic interpretation, a compass is used to measure distance (in addition to drawing perfect circles). Appendix IV of the Rules also seems to suggest DeChambeau is violating the rules. But, DeChambeau is using his compass to work at scale to understand data already made available to players through pin sheets and green books, both of which are legal. So, DeChambeau isn't acquiring information from the use of the compass so much as synthesizing it.
The USGA will come out with a ruling on the matter, but DeChambeau has a reasonable case to continue using the compass.