Some rules in golf might not make very much sense, but they are still rules. You can't test the conditions of a bunker. No grounding your club in a hazard. If you drop a ball and it hits your ball marker and moves it, you could be penalized.
But they are the rules, and we golfers must abide by them. That's why on Friday, when Rory McIlroy went and swept some sand out of his way on the ninth green, he knew almost instantaneously that a two-shot penalty was heading his way.
You see, removing sand in your line is totally fine if your ball is already on the putting surface, but Rory wasn't, and after brushing some sand away, was told by playing partner Luke Donald that what he did might not be legal.
"I just brushed the sand and Luke was like, 'I don't think you can brush sand off the fringe,'" McIlroy said. "I'm like, 'Oh, yeah, you're right.' Just one of those things."
He went on to make double-bogey on the hole, his second of the day, but managed to make three birdies over his closing nine holes to post an even-par round of 72, keeping him at 5-under for the week and just two shots back of leader Thorbjorn Olesen.
While McIlroy might have struggled with some rules problems, playing partner Tiger Woods was having a fine day, and his 3-under 69 has him at 5-under as well, and in a great position for the weekend.