The grading brief? Rate the world's top-10 players, plus the main contenders.
This weekend? Hasty change in the rules because an unprecedented six of the top 10 flew home on Friday evening.
So we'll deal with the four who made it, add the four men who shared the 36-hole lead, and throw in a few extra selections whose deeds demand a grade.
On Moving Day who went forward? And who went backwards?
It's difficult to back up a really low round. Rickie Fowler opened the week with a 65 and followed it with 73; on Friday, Matsuyama smoothed a 65 of his own and his response was a 71. He actually maintained the pace by turning in 2 under, but three back-nine bogeys might have left him too far back to contend on Sunday, despite a pair of birdie-4s late in the day getting him under-par for the round.
World ranking: No. 4
Score: 74-65-71 (-6)
Completing his third round before the leaders had even teed off must have hurt a guy who thinks only of winning major championships. Spieth couldn't get it going on the front nine (even-par) and then played the back nine like a man whose ambition was thwarted, limping home with one birdie, three bogeys and an ugly double-bogey 7 at the last.
World ranking: No. 5
Score: 73-71-76 (+4)
An exquisite pitch into the final green confirmed a third under-par round of the week, yet it's not quite happened and he's yet to break 70. As a response to his Masters win it's not been a bad effort; an 11th U.S. Open top-25 is in his sights Sunday.
World ranking: No. 7
Score: 70-71-71 (-4)
Despite three front-nine birdies when Fowler made a second bogey of the day at No. 13, he trailed the lead by 4 and all of his week's good work was under threat. Cue four vital putts holed from inside 10 feet. The first three were for a hat-trick of birdies; the last saved par on the final green. Eighteen of the past 20 U.S. Open winners were T-5 or better after 54 holes; the flat stick hauled Fowler back into the picture at solo fifth.
World ranking: No. 9
Score: 65-73-68 (-10)
The last man to make a triple bogey in a U.S. Open and still win? Tiger Woods at Pebble Beach in 2000. The last to make two triple bogeys and win? It's not going to be Casey. As in the second round, Casey's immediate response to the triple was another dropped shot. Unlike Friday, there was no avalanche of birdies to make up for it. A day to forget.
World ranking: No. 14
Score: 66-71-75 (-4)
It's important not to patronize a professional golfer who knows how to win on the PGA Tour and is contending for a major championship, but to compare Harman with those big-hitters around him on the leaderboard is like comparing a race car with a station wagon. Thing is, Harman might not have the gas, but he's deadly with his steering, missing just five fairways through three rounds and when he found the hay on the 17th? He chopped it out and got it up-and-down from 90-yards. He's a golfing craftsman at the top of his game in a week that began with one lefty (Phil Mickelson) making headlines, but might end with another stealing the limelight.
World ranking: No. 50
Score: 67-70-67 (-12)
Exactly 44 years to the day after Johnny Miller thrashed his famous 8-under-par 63 to win the U.S. Open at Oakmont, Reed had a 5-foot putt on the 18th green to tie that score as the lowest in relation to par in the tournament's history. It lipped out, so Reed only earns an A, but his eight birdie-one bogey round gives him an outside shot of claiming a first major championship top-10 on Sunday, and perhaps doing it in style.
World ranking: No. 19
Score: 68-75-65 (-8)
Just one hour after Reed narrowly failed to equal Miller's record, Justin Thomas broke it in sensational style, smashing two 3-woods to 8 feet on the 667-yard par-5 18th hole and draining the eagle putt for his 63, the first 9-under in U.S. Open history. It's the second time this year he's made eagle-3 on the final hole to complete a remarkable scorecard, having done so when posting 59 on his way to winning the Sony Open in January. Like Reed, Thomas heads into the final round having never before recorded a major championship top-10 and he, too, will be eyeing a disruption of that trend with a win.
World ranking: No. 13
Score: 73-68-63 (-11)
The Englishman recently revealed that, had his life taken a different path, he'd have been an actor and, on the biggest stage of his golfing career, he appeared to be relishing every second as he played 17 holes with flawless magnificence. Out of nowhere he forgot his lines on the last, making a bogey-6 which dropped him out of a tie for the lead. If he puts that one hole behind him, he can still star on Sunday at the U.S. Open.
World ranking: No. 33
Score: 67-70-68 (-11)
He's chasing a fourth successive U.S. Open top-20 finish and doing it in style. He's missed just five of 42 fairways all week and landed 45 of 54 greens in regulation. Koepka made just one error Saturday, chalking up a bogey-5 at the third, but otherwise he was long and accurate with his game, whilst relaxed and joking with playing partner Tommy Fleetwood.
World ranking: No. 22
Score: 67-70-68 (-11)
The German started Saturday at 3 under for the tournament with not one major winner ahead of him on the leaderboard (although Sergio Garcia was alongside.) As a two-time major champion himself, a few sage observers suggested there was an opportunity for him to make a move. Well, he moved all right. Trouble is, he went backwards.
World ranking: No. 58
Score: 72-69-75 (Even)