U.S. Open forecaddie: Running analysis of Round 1 at Oakmont

Stay tuned throughout the day as theScore keeps you updated with insights and analysis from Round 1 of the U.S. Open.

Welcome!

We tracked all the action from Oakmont Country Club during Round 1. We focused on the leaders, marquee players, and any surprises throughout the day. (All times ET.)

8:45 p.m. - Here's how the top of the oddsboard looks after Day 1:

Jon Rahm is the favorite at theScore Bet/ESPN Bet after his opening-round 69. He led the field in strokes gained: off the tee in Round 1, which usually translates to success at Oakmont.

Scottie Scheffler struggled big time relative to his standards. His 3-over start puts him seven shots off the lead. He was still 1.63 shots better than the field average.

Brooks Koepka shot 68 and gained 6.72 strokes on the field, his best round in a major since winning the 2023 PGA Championship. His odds shifted the most Thursday, moving from +7000 to +900.

Rory McIlroy started the day with two birdies in his first three holes, but a back-nine 41 ruined his round. He shot 74 to end the day in a tie for 62nd. The cut will likely be either 6-over or 7-over, according to DataGolf, so McIlroy will need to be careful on Day 2.

7:20 p.m. - Sungjae Im fell off the pace with three bogeys in his last seven holes after touching 5-under for the day. He finishes Round 1 in a tie for third, two back of J.J. Spaun. Im's last top-10 finish came at the Masters in a down year where he's struggled with his approach play. He's lost strokes with his irons in 10 consecutive events.

6:55 p.m. - Scheffler cards a 3-over 73, a round that contained an uncharacteristic six bogeys. His score is still better than the field average, but he only hit seven of 14 fairways and 11 of 18 greens in regulation. He will have to clean up all aspects of his game if he's going to climb back into contention.

6:30 p.m. - Koepka posts a 2-under 68, a round capped by back-to-back birdies. He gained nearly three strokes around the greens in Round 1, something he will need to continue to do to stay in the hunt. The two-time U.S. Open champ, who has missed the cut in both majors contested this season, was +7000 before the tournament but has seen his odds shrink to +1000.

6:05 p.m. - Oakmont has knocked Scheffler off his game. The world No. 1 is rattled and is 3-over through 15 after missing a very short putt for par.

5:35 p.m. - Here comes Rahm. The Spaniard eagles the par-5 fourth to jump to 2-under for the tournament. He moves atop the oddsboard ahead of Scheffler at theScore Bet/ESPN Bet.

5:15 p.m. - There's no one specific skill that's currently elevating players to the top of the leaderboard. Im has only hit six of 10 fairways, but is being saved by his chipping. Spaun gained four strokes putting, and the only real long hitter near the top of the board is Sam Burns. So far, the players with the best all-around game are finding success at Oakmont.

5:05 p.m. - Only Nos. 4 and 17 are playing under par today at 0.08 and 0.07 strokes, respectively. The remainder of the course is brutal, with a current scoring average of 4.83 over.

4:45 p.m. - Im gets to 4-under to sit tied with Spaun atop the Day 1 leaderboard. Jordan Spieth, Collin Morikawa, Patrick Reed, Koepka, and Burns are all 1-under and off to nice starts to their tournaments. Justin Thomas, on the other hand, is 5-over through 11 and heading toward another disappointing major result.

4:10 p.m. - Oakmont is keeping the world No. 1 in check. Scheffler makes the turn at 2-over par after carding four front-nine bogeys. His live odds have drifted to +425 at theScore Bet/ESPN Bet, nearly double his pre-tournament odds of +250.

3:05 p.m. - The scoring average at Oakmont is approaching 5-over. While some players are finding ways to make birdies, the majority of the field is getting beaten up. The cut is trending toward 7-over, with 8-over a possibility, according to DataGolf.

2:50 p.m. - A few players in the afternoon wave are making noise early into their rounds. Sam Burns is 3-under through 5, carrying his strong finish at the Canadian Open to Oakmont. Koepka drained a lengthy eagle on No. 6 to sit at 2-under for the day. Patrick Reed made a rare albatross on No. 4 from 286 yards to jump to 2-under par.

2:15 p.m. - Scheffler is three holes into his first round, with a birdie on the second and a bogey on the third to sit at level par. He's the heavy tournament favorite at +200.

1:35 p.m. - Xander Schauffele finishes birdie-birdie to post a 2-over 72, the same score Ludvig Aberg turned in. Rory McIlroy stumbles home to an opening-round 74. Bryson DeChambeau cards a 73, where he lost all of his strokes on and around the green.

1:05 p.m. - McIlroy's round is unravelling. He's five over in his last five holes, capped by a double-bogey on the lengthy par-3 eighth. He continues to find himself in horrible spots at Oakmont, hacking his ball out of thick rough far too often.

12:40 p.m. - Spaun cards a bogey-free 66 - a truly incredible round at Oakmont - to take the early first-round lead of the U.S. Open.

12:25 p.m. - Notable players struggling in Round 1: Shane Lowry (+6), Cam Smith (+5), Patrick Cantlay (+4), Justin Rose (+4), Schauffele (+4), Tommy Fleetwood (+4), and Hideki Matsuyama (+4). The extremely early look at a potential cut line is 6-over and is trending toward 7-over, according to DataGolf.

12:10 p.m. - Oakmont is starting to punish the field. The scoring average is 4.76 strokes over par, and only two players are at 2-under or better. Spaun continues to lead at 4-under. He's bogey-free and is gaining nearly four shots on the field with his putter.

11:45 a.m. - Rory McIlroy avoids utter disaster on the par-5 fourth. His drive ended up in the right rough, and it took three shots to get back to the fairway. His approach from 178 yards settled 30 feet from the cup, and he drains the lengthy bogey effort to fall back to even for the tournament. He easily could have walked off the fourth green with an eight.

11:30 a.m. - It's been an interesting 12 holes for DeChambeau. He's hitting the ball well, ranking seventh in strokes gained: off the tee and ninth in strokes gained: approach. However, the defending champ has lost nearly 1.5 strokes around the green, most of those coming on the par-5 12th, where he was over the back of the green in two shots and walked away with a bogey.

10:30 a.m. - The level of concern was high for Rory McIlroy this week after an ugly showing at the Canadian Open, but that worry has vanished after nine holes. He's 2-under, has gained over a stroke off the tee and nearly two shots on the greens. McIlroy is down to +700 on the oddsboard after getting as long as +1600 before the tournament started.

10:05 a.m. - The scoring average is currently 4.46 strokes over par. The front nine is playing over 1.5 strokes tougher than the back.

9:40 a.m. - Oakmont is conceding birdies early. Spaun is 4-under through nine, and there are nine players in red numbers already. It's also showing its teeth, with 15 players 3-over or worse.

8:45 a.m. - Dare we say McIlroy looks ... back? After he couldn't find a fairway last week in Canada, McIlroy launched his first beauty of the day, a 392-yard drive on the par-5 12th, leading to his second birdie.

8:30 a.m. - The morning's featured groups are on the course, with defending champion DeChambeau and McIlroy among them. It's extremely early into this tournament, but Spaun has the lead at 2-under through four holes. Aberg and McIlroy are also under par early in Round 1.