On the eve of the 2017 Open Championship, The R&A made a bizarre change to the course in which one of the fairways is now considered out of bounds.

The unusual decision came after at least one golfer decided that the ninth hole would be easier if they didn't actually play the ninth fairway.

According to NBC broadcasters, Jason Day’s caddie, Colin Swatton, inquired about playing the ninth hole down the tenth fairway. As this graphic from NBC shows, an approach shot from the tenth fairway could be considerably shorter than a typical approach from the ninth fairway.

While it is not unheard of for players to play on other fairways — intentionally or not — this situation had one big problem, literally.

There is a big grandstand that sits just to the right and in front of the ninth tee box.

Players teeing off on No. 9 have a big grandstand off to the right. NBC Sports

Geoff Shackelford of Golfweek noted that the chief referee of the tournament announced just before the start of the tournament that the tenth fairway would be considered "out of bounds" for players playing the ninth hole.

NBC also noted that there would be concern for the safety of players on the tenth hole approaching the ninth tee box.

Here is the view from the tenth tee.

As Sheckelford noted, it is not just the shorter length that enticed the players, it was also the difficulty of the tee shot at No. 9.

"The ninth hole fairway is so hard to see that the club has built a permanent viewing platform to determine when the landing area is clear. Couple that with narrowness, strong undulations and it’s little wonder why a clever caddie such as Swatton would suggest his player drive to a wider, flatter and more direct path to the green."