If a playoff is needed to determine the winner of the 150th Open Championship in St. Andrews, the first, second, 17th and 18th holes will be used.
The Open is employing a four-hole aggregate playoff on the Old Course, if there is a tie at the top following regulation. If players are still deadlocked after those four extra holes, they will repeatedly play the 18th hole in sudden death.
Officials used a three-hole system in 2019 and '21 (the championship was canceled in 2020 because of the pandemic), but said the aggregate number depends on the venue.