The cut at the U.S. Open golf tournament takes place following two rounds (36 holes) of the four-round (72-hole) tournament. What is the cut rule, the formula the USGA uses to determine which golfers go home and which continue playing beyond 36 holes?
The U.S. Open cut rule is that all golfers in the top 60 plus ties make the cut. Golfers outside of the top 60 plus ties are cut from the field and fail to advance to the final two rounds of play.
The current cut rule went into effect beginning in 2012; for many years prior to that, the U.S. Open cut rule included the common "and all golfers within 10 strokes of the lead" provision. That provision meant that if a golfer was outside the Top 60 - say, in 68th place - but was within 10 strokes of the leader's score, he still made the cut. However, that 10-strokes rule was eliminated beginning in 2012.
So to repeat: The U.S. Open cut rule is Top 60 plus ties. The "plus ties" provision means that there are no playoffs for the final spots in the Top 60. Say 58 players are at +5 or better, and another seven players are at +6. All seven of those golfers at +6 make the cut because of the "plus ties" provision, so in that example 65 golfers would make the cut. There is no limit on the number of golfers who can make the cut by virtue of the "plus ties" provision. If, for example, 18 golfers are tied for 60th place, then all 18 make the cut.
The U.S. Open first used a 36-hole cut in 1904.