A tougher-than-expected Aronimink Golf Club generated an historically bunched leaderboard Thursday at the PGA Championship.

Here are the top numbers and notes to know from Round 1 of the season’s second men’s major.

1. Seven players are tied for the lead, the most after any round of a men’s major championship since the 1977 U.S. Open’s first round at Southern Hills. There are a staggering 48 players at or within three of the lead, the most after any round in the modern era of major championships.

While Aronimink caught some pre-Championship flak as potentially being defenseless against this field, the old Donald Ross design must have been quietly cackling to itself. At 3 under, this is the highest score to par to lead after Round 1 of a PGA Championship in 18 years. At the 2008 PGA at Oakland Hills, Robert Karlson and Jeev Milkha Singh shared the first-round lead at 2 under.

2. One of the most interesting storylines entering the week was seeing how differently Aronimink would play in a major championship setting compared to the torching it took in the 2018 FedExCup Playoffs. At the ’18 BMW, five holes played over par for the week. Eleven did Thursday. The 2018 BMW yielded the easiest green in regulation rate of any course on the PGA Tour that season (77.4 percent). That number dipped to 63.2 percent in Round 1.

The penalty for hitting a drive in the rough was significant. Players hitting approach shots from the rough in Round 1 had an average proximity to the hole 13 feet farther away than from the fairway. For context, that differential on the PGA Tour this season averages just under nine feet.

How about around the green? The field had an average proximity to the hole of 11 feet on chips, pitches and greenside bunker shots in Round 1. That’s 33 percent farther away than the PGA Tour average. Tightly tucked hole locations, plus chilly temperatures and wind, also assisted in making Aronimink the biggest star of Round 1.

3. World number one and defending champion Scottie Scheffler is part of that seven-man jumble at the top. He is just the third defending PGA champ to hold at least a share of the 18-hole lead. In the previous two instances – Tiger Woods in 2000 and Brooks Koepka in 2019 – the player won back-to-back Wanamaker Trophies. While Scheffler has more rounds led in majors than anyone since 2022 (13 and counting), this is the first time in his career he’s had a piece of the lead after Round 1.

Scheffler rolled in more than 120 feet of putts in Round 1, the sixth-highest sum of any player in the field Thursday. Scheffler picked up more than three strokes on the field on the greens, just the third time he has done that in his last 67 major rounds. He was also precise off the tee, taking less than driver on several occasions on Thursday. It resulted in hitting the first 12 fairways of the round, by far his most in a row to begin a major championship.

From the beginning of 2024 through this year’s Masters, Scheffler was 60 under par in the majors. In that same time span, the other six players who shot 67 on Thursday had a combined score to par of 152 over par. Scheffler had more major rounds in the 60s in that stretch (16) than the other six combined (12).

4. Former world number one and two-time major champion Martin Kaymer is among the group at 3 under after shooting his lowest round in a major championship in more than 2,100 days. Now 41, Kaymer had just one bogey on his card on Thursday. He’s the oldest player to hold a share of the first-round lead at the PGA since Jim Furyk in 2013.

Kaymer is one of a dozen major champions at or within two strokes of the lead after Round 1. Per the Elias Sports Bureau, that’s the most after any round in men’s major history, breaking the old record of 11 after Round 1 of the 1999 Masters Tournament.

5. None of the other five men at 3 under – Aldrich Potgieter, Stephan Jaeger, Min Woo Lee, Ryo Hisatsune and Alex Smalley – have previously held the lead after any round of a major championship. Potgieter, the reigning PGA Tour Rookie of the Year, is just 21 years old, making him the youngest man to hold a share of the lead after any round of the PGA since Sergio Garcia did it at age 19 in 1999.

Smalley entered the week in good form, finishing in the top 20 in each of his last four PGA Tour starts. Playing in just his fifth career major championship, the 29-year-old Duke product is seeking his first-ever PGA Tour victory.

The popular Lee, brother of multiple-LPGA-major-champion Minjee, is the most accomplished of the group, with a PGA Tour win and three on the DP World Tour. Lee led all players on Thursday in strokes gained tee to green, picking up nearly five and a half strokes on the field in that metric.

Aldrich Potgieter is the 2025 PGA Tour Rookie of the Year. (Richard Heathcote / Getty Images)

6. Seven more players are just one shot back after opening with 68s. Shane Lowry, Xander Schauffele and Patrick Reed are part of that group, each a major champion in their own right. Reed recorded the lone bogey-free round by the field on Thursday, the third time he has gone without a dropped shot in his major championship career.

Lowry was 1 over through eight holes before a pitch-in eagle from about 40 yards out at the ninth. The 68 is his best start to a major since the 2024 Open, when he shot a first-round 66 before ultimately finishing in sixth place. Schauffele made five birdies and had positive strokes gained in every category in Round 1. Since 2017, only Scheffler has a better first-round scoring average in majors than Schauffele does.

7. Two-time major winner Jon Rahm is under par after Day 1 despite not making a single putt of six feet or longer. Rahm holed out from 98 yards away on the second hole (his 11th) for eagle, the biggest highlight of his first day. He picked up 4.3 strokes gained tee-to-green, his best in a major round since Sunday at Oakmont last summer.

8. Reigning Masters champion Rory McIlroy raised some eyebrows earlier this week when he said Aronimink didn’t require much strategy off the tee. After an opening 74, he won’t be the only player reassessing this course after a tough Round 1.

Like the first round of last month’s Masters, McIlroy hit just five fairways on Thursday at Aronimink. At Augusta National, McIlroy was able to play the par 4s and 5s in which he missed the fairway in 3 under on Day 1. Today, he played those nine holes in 5 over. Rory needed 34 putts on the day, his most in any PGA Championship round in seven years.

McIlroy staggered into the clubhouse, making bogey on each of his last four holes in the round. In the nearly 1,000 official rounds of his PGA Tour and major championship career, he had never made bogey or worse on the last four holes in any round. No player has opened a PGA Championship with 74 or higher and gone on to win since Payne Stewart at Kemper Lakes in 1989.

9. It was another difficult start to a major championship for Bryson DeChambeau, who made just one birdie in an opening round 76. DeChambeau is now a combined 20 over in Round 1 of his last four major starts. His short game has been a primary culprit in those struggles: he was just 1-of-7 scrambling Thursday, and in his last four first rounds of majors, he’s lost more than 10 strokes to the field on shots around the green.

DeChambeau will have work to do on Friday to qualify for the weekend. Should he miss the cut, it would mark the first time in his career he’s missed the cut in each of the season’s first two majors, and the first time he’s missed consecutive major cuts since 2017.

10. Forty-five of the last 50 major winners in the men’s game have been within five of the lead after Round 1. That casts a gigantic net, as a preposterous 92 players fit that restriction entering Round 2. Per Elias, that’s seven more than after any other round in modern major championship history.