The Rules of Golf are in the spotlight again after Russell Henley was hit with a huge penalty that sent him packing at the Mayakoba Classic

Russell Henley was signing a few golf balls for some wide-eyed fans after the second round of the Mayakoba Golf Classic. Henley was happy – he had just shot a 69 to add to his opening 66 that would take him into the weekend well in contention. The kids were happy – they were getting the autograph of a three-time PGA Tour winner, including his debut win at the 2012 Sony Open. But the Rules of Golf had other ideas.

Happiness quickly turned to confusion when Henley noticed something was wrong. While sorting through his balls, Henley noticed one was different than the Titleist ProV1x with which he normally plays.

“It was a small dash, a different way it was marked that would have been easy to overlook,” PGA Tour rules official Brad Fabel explained. “He came to us and said he didn’t know how it had gotten in his bag.”

So which of the Rules of Golf did Henley break?

Well, it’s not actually one of the Rules of Golf itself, but professional and high-ranking amateur tournaments adopt a “one ball rule”, which says players must use the same type of ball throughout a single round.

Because Henley had used a ball different to his ProV1x with which he had started his round, he was penalised.

Henley admitted he had used the rogue ball on holes 9-12, meaning a two-shot penalty for each hole – eight in total – and that 69 quickly became a 77 and a missed cut.

Within the Rules of Golf, the “one ball rule” falls under Rule 20.3: “Situations not covered by the Rules”.

It explains that “any situations not covered by the Rules should be decided by the committee” as long as it’s “considering all circumstances” and “treating the situation in a way that is reasonable, fair and consistent with how similar situations are treated under the Rules”.