Sunday is proving, as usual, to be a hellish experience for the golfers at the US Open. Merion Golf Club -- after initial expectations by some to be an easier-than-usual 18 -- has turned up in typical US Open style to be strenuous on the scoreboard.
So with the top of the leaderboard thinning out, what's the protocol for a playoff at the US Open? Remember, playoff formats for golf tournaments vary. Here's how Merion will play out, should it need a playoff.
If the weather holds off and two or more players finish 72 holes with the same score, they will play a full 18 holes on Monday. The US Open is the only major golf championship to implement a full round as means to a playoff. The leader after those 18 playoff holes on Monday is the champion.
However, if scores of two or more players are still even after a fifth round/90 holes, the 91st hole becomes sudden-death format, with the lowest score winning on the first possible hole. Those holes would also be played Monday, weather permitting. Only four times has the US Open needed to play to sudden death after 90 holes: 1990, 1994 and 2008 (the famous Tiger-Woods-over-Rocco-Mediate Monday face-off).
The sudden-death playoff format for the 91st hole and beyond was instituted in the '50s. In total, there have been seven playoffs in US Open history, coming in 1925, 1931, 1939 and 1946, in addition to three mentioned above. The 18-hole playoff format was initially used by all major golf championships, but only the US Open still keeps it in place today.