The leaderboard during the final round of The Open Championship at Carnoustie is making it difficult for anyone to find separation, and it's now possible that the Claret Jug will be handed out after a playoff following Round 4.

With that in mind, let's take a look at playoff rules for The Open should we come to it. 

  • Format: Four-hole aggregate
  • Holes: 15-18

This format was first used in 1989 when Mark Calcavecchia beat Wayne Grady and Greg Norman. More recently, Zach Johnson bested Louis Oosthuizen and Marc Leishman at St. Andrew's in 2015.

In total the four-hole aggregate playoff has been used nine times by The Open to crown its Champion Golfer of the Year.  

At Carnoustie, the four playoff holes will be 15, 16, 17 and 18 with only one par 3 between them. That closing run of 16-17-18 is among the toughest finishes in all of major championship golf, and this week those holes have ranked as three of the four hardest holes on the course.

In other words, to anyone who gets into a playoff at The Open: good luck.