The PGA Championship has the biggest logjam at a major in 24 years.

NEWTOWN SQUARE, Pa. (AP) — Not many players imagined Aronimink Golf Club and its wild, wavy greens would be so tough on scoring at the PGA Championship. Even fewer would have predicted Alex Smalley and Maverick McNealy to be atop the leaderboard Friday. What to expect the rest of the weekend? Pretty much anything. "Anyone who makes the cut, they've got to feel they have a shot in the tournament," said Rory McIlroy, who found himself only five shots behind with 29 players — including Scottie Scheffler and six other major champions — ahead of him. Two long days at Aronimink produced the highest 36-hole score to par to lead the PGA Championship in 14 years. The 15 players separated by two shots made it the biggest logjam going into a weekend at a major since 2002. There's more traffic at Aronimink than Philadelphia's Schuylkill Expressway at rush hour. The difference between first and worst among 82 players who made the cut was only eight shots, unusually tight for any tournament, much less a major. Smalley, in only his fifth major championship, overcame three straight bogeys after making the turn and closed with a birdie for a 1-under 69. McNealy, who has never been among the top 25 in any major through 36 holes, fell back with a pair of late bogeys in his round of 67. They were at 4-under 136, the highest 36-hole score to par for co-leaders in the PGA since 2012 at Kiawah Island. Chasing them? It's a long list. Hideki Matsuyama, the 2021 Masters champion, and world No. 10 Chris Gotterup were among those one shot behind. They were followed by Scheffler, two-time PGA champion Justin Thomas and Cameron Young, who has won The Players Championship and at Doral the last two months. Jon Rahm and Ludvig Aberg. Patrick Reed and Patrick Cantlay. And on it goes. "A bunched leaderboard like this, I think it's a sign of not a great setup," McIlroy said after a 67. "It's easy to make a ton of pars, hard to make birdies, and ... it feels like bogey is the worst score you're going to shoot on any one hole." It was tough to hit shots close. And then it was tough to get long putts close. "This is the hardest set of pin locations that I've seen since I've been on tour," Scheffler said after salvaging a 71. "And that includes U.S. Opens. That includes Oakmont." McNealy became the only player to reach 6 under at any point this week. He holed a bunker shot for eagle on the par-5 16th and remarked to his brother and caddie, Scout, that he was amazed and how well he was playing. And then he added three birdies over his next five holes until some mistakes caught up with him, as they did just about everyone. "This is unfamiliar territory for me," McNealy said. Gotterup and Matsuyama had the toughest time by playing in the morning, when the temperatures barely cracked 50 degrees (10 Celsius) and the wind was ripping. Gotterup, who played college golf at just up the New Jersey Turnpike at Rutgers, played had enough Jersey toughness to handle it just fine, and he poured it on at the end with three straight birdies for a 65, the low round of his championship. "Today would definitely be one of those days where I would be on the couch and I would be like, 'How did he hit it there?' and 'How did he do this?' And then you're out there, and it just feels like it's impossible," Gotterup said. Scheffler had a share of the 18-hole lead for the first time in a major, and then looked like anything but someone with consummate control of his game. He didn't hit a fairway until his ninth hole (No. 18), and dropped three shots in four holes after driving into the thick grass. He might have saved his round on the par-3 14th when he hit a beautiful lag putt from 80 feet for a two-putt par. That settled him, and he closed with an up-and-down birdie on the par-5 ninth. Scheffler was joined by Thomas and Young at 2-under 138, and Aberg, the polished Swede who had four birdies in a five-hole stretch on the tougher back nine for a 66. The cut was at 4-over 144. Among those headed home was Bryson DeChambeau who was 10 over at one point. He closed with three straight birdies, far too late for the two-time U.S. Open champion. Garrick Higgo's two-shot penalty for being late to the first tee on Thursday cost him a share of the lead on Thursday, and it cost him the cut on Friday. He shot 76 and missed by one. McIlroy and Jordan Spieth (73) were tied for 30th, both with the Grand Slam on their minds. Spieth needs the PGA for the career slam, McIlroy as the Masters champion is the only one with a shot at the calendar slam, which has never been done. But they still had a chance. So many of the pin positions were hard to reach — from the fairway and at times from the putting surface — that no one was safe. McIlroy, who opened with a 74, played bogey-free with one goal in mind — stay in the mix and see what the weekend presents. He feels the PGA of America already used up several of the toughest pin positions. With slightly calmer conditions, the race could just be starting. "Yes, it's bunched," he said. "But you get on a run with wedges on that front nine and you shoot 4, 5 under and all of a sudden you're right in the thick of things."