FARMNINGDALE, NY -- Remember when PGA Championships were easy? Don't let Brooks Koepka's 63 in Round 1 fool you: Thursday's average score ballooned to 73.1 as Bethpage Black bared her teeth even without any inclement weather in play. The end result is a loaded leaderboard topped by Mr. Muscles himself, who dropped that bogey-free number Tiger Woods said, "was probably the highest score he could have shot today. He left a few out there with a couple putts that he missed. But it could have easily been a couple better."

As for everyone else, it wasn't as pretty. Only 16 players broke par, and only three shot 67 or better. Thursday was certainly not a traditional PGA Championship first round (to wit: in last year's Round 1 at Bellerive, 61 golfers broke par and 15 shot 67 or better). Even though this isn't a U.S. Open, Bethpage Black played nasty amid stunningly good weather on Long Island. It looked like a fun day to tackle the People's Country Club, even if it was not.

"This doesn't feel like totally different golf course to how we've played it in Barclays Championships in the past," said Justin Rose, who shot even-par 70. "It's just tougher, and I think it's a bit more demanding."

I thought it was perfect for a major: perfect conditions, perfect setup and a perfect Round 1. I'm not sure everybody dropping those 74s and 77s would agree, but that's OK. The PGA Championship has done a great job letting the course dictate how its tournament plays out instead of forcing the issue. That's a good thing, even if it means the man out front looks like he's going to win the next 15 of these in a row.

Here are a few notes and thoughts on Round 1 from Bethpage Black.

1. Koepka by the numbers: There are innumerable remarkable records and historic figures that came out of Koepka's 63 on Thursday, but the most remarkable to me -- the one I keep coming back to -- is the 10.1 strokes gained on the rest of the field. If history is any indication, that will go down as one of the great rounds of 2019 when everything is said and done. Again, among the best players in the world in one of the strongest fields of the year, Koepka was five strokes better than all but two players.

2. Will it hold? The biggest question now is how sustainable this big lead is for Koepka. The only real precedent we have on this course is Mike Weir in 2009 when he shot 64 to lead Peter Hanson by two and another group by three. He finished 70-74-74 to end T10 for the week. Given Koepka's recent history at major championships, I'm guessing he's not going to finish 70-74-74, which means somebody is going to have to run him down. He putted out of his mind on Thursday with just two of his seven birdie putts at less than 12 feet, which is definitely not sustainable. But his lead might also be big enough that it doesn't much matter. Regardless, if somebody does catch him, it won't be done in a day but rather one bite at a time.

3. Jordan Spieth's opportunity: It looked for a while like Spieth might make a late run at Koepka, but he was upended in the same place Tiger Woods was upended earlier in the day: the 10th hole. Spieth pulled his drive -- the club that he said has been holding him back -- so badly that he had to hit another ball and ended up making a six. That double erased all the work he'd done on the front side, and though he recovered to shoot 69 (see below), he whiffed on an opportunity to really put himself in a good spot for Round 2.

4. Let's check in on John Daly: Well, OK then.

5. Rory McIlroy can't find the cup: It was a tough day for one of the pre-tournament favorites, who doubles as the best golfer in the world in 2019. He finished 120th around the greens, 115th in putting and took 35 putts on the day. Now he's nine back and pretty much out of it.

6. Poor Danny Lee: Imagine gaining nine strokes on the field, being three up on Tommy Fleetwood and four on everyone else ... and looking up at Koepka flexing all over you. Such is life in a major championship world in 2019. Also, I'm still not exactly sure how Lee shot a 64 on Thursday after finishing 135th in driving.

7. (More!) Koepka: This round was great, sure, but it also fits in nicely with all the work Koepka has been doing lately at majors. Here's a look at his last 10 major rounds. All 10 rounds under par with seven of them in the 60s. His combined score in these 10 major rounds is -36. Those are astonishing numbers.

  • Eagles: 2 
  • Birdies: 53 
  • Pars: 107 
  • Bogeys: 15 
  • Doubles: 3 

8. Big names at 1 under: Look at the crew that shot 69 on Thursday. It includes Phil Mickelson, Jason Day, Jordan Spieth, Dustin Johnson, Patrick Cantlay and Rickie Fowler. If somebody not named Koepka wins this tournament, I bet it comes out of this group. Spieth is the most fascinating, but Johnson and Day probably have the most staying power.

9. Let's talk about Tommy Fleetwood: It was Shinnecock redux for a day at Bethpage with Koepka and Fleetwood cruising around in a combined 10 under (they combined to shoot 9 under in the final round at last year's U.S. Open). Fleetwood may have also shot the quietest third-best first round by a top-20 player in the world in major championship history. Zero surprises this ball-striking stud crushed at a course that once hosted two U.S. Opens.