Rules of Golf
Rules Review: I accidentally hit my ball while making a practice swing. Does that count?
If you're like us, you're probably ready to fling your headcover at the next person who says "one" when you accidentally knock your ball off the tee. Not sure on the origin of this "tradition," but if you're guilty of doing it, you need new material.
Worse than just being lame, it's also wrong. If you accidentally knock your ball off the tee while making a practice swing, it doesn't count as an actual stroke and it's not a penalty. Simply re-tee and play on, as Rule 6.2b in the Rules of Golf explains. Just ask Zach Johnson, who did it very publicly on the 13th tee at the 2019 Masters (below) and, unbelievably, again at the 2022 WM Phoenix Open. More good news: You also can replace your ball without penalty on the putting green if you accidentally move it in any way, including while making a practice swing (Rule 13.1d).
OK, now the bad news: After you’ve teed off and your ball is in play, there are times when moving it while making a practice swing will cost you. With one exception we’ll cover in a moment, the Rules says if your ball is in the fairway, rough, bunker, etc., and you cause it to move with your practice swing, you’ll need to add a penalty stroke to your score and the ball must be replaced. Thankfully, the practice swing itself does not count as a stroke, too. (Remember, the definition of a stroke is the "forward movement of a club made to strike the ball." A practice swing does not qualify.)
The exception when the ball is in play is that you're not penalized for accidentally moving it if it’s still in the teeing area, which is the zone two club-lengths behind the markers. This is important to remember should you decide to re-tee the ball after hitting your drive out-of-bounds. If it falls off again, there is no penalty. Also, if for some reason your drive doesn't leave the teeing area—maybe you nearly whiffed and it fell off the tee—you're still OK if you make a practice swing and it moves again. You might need to get your contact-lens prescription adjusted, but there's no penalty.
In each case, put the ball back where it was an play on. If for some reason you forget to move the ball back and play it from its new location, it's a two-stroke penalty or loss of hole in match play.