Golf's four major men's championships -- the Masters, US Open, British Open Championship and PGA Championship -- all now have modern playoff formats designed to make sure a champion is crowned on Sunday (or, God forbid, Monday).
The USGA, which runs the US Open, in 2018 changed the US Open playoff format to a two-hole, aggregate-score playoff, ending the practice of 18- or 36-hole playoffs for the prior 33 playoffs in the 117-year history of the national championship.
Now the US Open joins the British Open Championship and PGA Championship in going to multi-hole, aggregate-score playoff formats.
The R&A went to a four-hole, aggregate-score playoff which was first used in 1989 when Mark Calcavecchia won the claret jug.
The PGA Championship has a three-hole, aggregate-score playoff, which it first employed in 2000, when Tiger Woods beat Bob May by a shot at Valhalla in Kentucky.
The Masters playoff format remains sudden death, typically beginning on the 18th hole before eventually going to the 10th hole in a mini-loop.