The U.S. Open playoff format will look much different in 2018 and beyond.
While the national championship used to boast a 18-hole Monday playoff that was the longest of any of the sport's four majors, those days are over. It was announced earlier this year that the U.S. Open will now use a two-hole aggregate playoff. If competitors are still tied after two holes, they will move to sudden death. The new format is more in line with the PGA Championship (three-hole aggregate) and British Open (four-hole aggregate). The Masters uses a sudden death playoff.
The last U.S. Open playoff was in 2008 at Torrey Pines, when Tiger Woods beat Rocco Mediate on the first sudden-death playoff hole after they tied after their 18-hole playoff. It was only the third time the U.S. Open needed sudden death to decide its winner since a format change in the 1950s.