There were a lot of strong opinions voiced on Golf Twitter about Valhalla Golf Club last week. One common criticism was that the vanilla layout and soft conditions did not allow for skilled players to separate, and that, in general, scores were bunched. However, it turns out the data tells a different story:

The skill separation values (y-axis) tell us how much a 1-stroke skill advantage was worth at each course; the average value across all courses will be 1. At Valhalla last week, the skill separation was 1.25, which means that high-skilled players beat low-skilled players by more than we would expect at a typical PGA Tour course. (For interested readers: these values come from a simple regression of SG on skill for each course.)

The score separation values (x-axis) tell us how spread out scores were. We’ve used the standard deviation of skill-adjusted scores as our measure of dispersion, which has an average value of just under 2.8 at PGA Tour courses. Last week’s value was 2.74. We don’t include players with raw skills below -2 (e.g. club pros) when calculating either of these metrics. Most of the outliers on the plot are courses that have only been played 1-2 times.

The PGA Championship has historically been the major that separates on skill more than any other (which we wrote about in 2020). This shouldn’t be surprising, as PGA setups are typically just longer and more difficult versions of PGA Tour setups. Last week at Valhalla was no different, with a skill separation value well above 1. It is important to remember that “skill” is based on a players’ past performances, so a course that appears to separate less on skill may actually just be testing a different style of play than what players normally face.

In a blog post from 2 years ago we looked into what drives differences in scoring variance across courses. There were 6 meaningful course characteristics: course difficulty, course par, number of penalty strokes, penalty for a missed-fairway, and GIR (lower GIR=more variance). It makes sense that harder courses tend to have more variance: the more shots that players have to hit, the more chances there are for separation to occur. The variance in scoring was slightly lower than tour average at Valhalla last week, but pretty in line with recent PGAs.

It’s understandable why lots of people disliked how Valhalla played last week. The soft conditions turned the event into a shootout which seemed out of place at a major championship. However, easy conditions should not be equated with a leveling of the playing field: good shots were still rewarded and bad shots punished, it’s simply that the punishment was mostly a lower likelihood of making birdie, rather than a higher likelihood of making bogey like we are used to at the majors.

Here are a few other interesting takeaways from last week’s data:

1) Valhalla played easy, but not that easy: the skill-adjusted scoring average was -0.2 strokes/round, which is the 10th-easiest of the 20 PGA Tour courses played so far in 2024.

2) Breaking things down by SG category, OTT and APP shots at Valhalla were both among the 5 easiest courses of 2024, ARG shots were about average, and putts were slightly easier than average. In other words, if Valhalla wasn’t 7500+ yards, it would have been one of the easier courses on the PGA Tour this year. Not very major-like.

3) The penalty for a missed-fairway at Valhalla was pretty steep: the 4th-highest among 2024 courses. However, not that many fairways were missed (4th-easiest fairways to hit).

You can dig into the full set of stats for Valhalla and other PGA Tour courses here.

Long Weeks

By all accounts (I unfortunately wouldn't know), playing and sleeping with the lead at major championships is mentally and physically exhausting. Staying focused on the present, doing media, and conserving energy all become a little more difficult with a lead. Xander Schauffele dealt with this from Thursday to Sunday last week, ultimately emerging as a very deserving major winner.

Most major winners don't have to deal with this pressure from day 1. Here are the win probability evolutions of the last 21 majors champions, sorted by the winner's average win probability during the week:

Schauffele's win probability jumped up to 35% after round 1, which he was able to maintain until pulling away late on Sunday afternoon. Among major winners since 2019, only Scheffler had a higher win probability after round 1 (2024 Masters). Brooks Koepka's win at the 2019 PGA Championship is the most dominant performance from a win probability perspective—although he only ended up winning by 2 strokes over DJ.

Justin Thomas holds the current title for biggest back-door major win. JT was T9 and 7 shots back through 3 rounds at the 2022 PGA, and our model gave him a mere 1.2% chance of winning prior to the final round. But it's Collin Morikawa who had the lowest average win probability en route to his win at the 2020 PGA. Morikawa jumped into the mix thanks to a Saturday 65 and was only 2 shots back heading into Sunday. His win probability was just 8.3% due to a stacked leaderboard that included Dustin Johnson, Brooks Koepka, and a young Scottie Scheffler! (Paul "The Closer" Casey was also in the mix.)

Unfortunately, being around the lead all week doesn't always result in a W. Here are the highest average win probabilities during major weeks by non-winners since 2019:

I think all golf fans felt like the 2022 Open Championship at St. Andrews was Rory's major. He hovered around the lead all week, eventually grabbing a share of it on Saturday night alongside Viktor Hovland—4 shots clear of eventual champion Cameron Smith.

The fact that two players from the 2022 PGA Championship are on this list further proves that JT stole that tournament.

Honestly, if you told me that Justin Rose didn't play in the 2019 U.S. Open (at Pebble), I would believe you. Turns out he was the first round leader and only one back heading into Sunday.

Rankings Update

With his PGA Championship win last week Xander Schauffele cemented himself as the second-best golfer in the world behind Scottie Scheffler. His DG Index (our measure of skill, in strokes-gained per round) is at a career high of +2.55 and puts him 12th on our all-time list. While he's still half a stroke worse than Scottie by our estimates, an index of +2.55 would be good enough to top the DG Rankings 91% of the time in the post-Tiger era (2011—present).

Xander and Scottie's average skill is +2.77 right now. No top duo that excludes Tiger Woods has had a higher average DG index in the time period our rankings cover (1995-present). The second-highest belongs to Duval and Love III in April of 1999.

Xander has actually reached the top of the DG Rankings before, albeit for just one week. In October of 2020 he reached a DG Index of +2.34 after winning the gross Tour Championship by 4 strokes (losing net by 3 to DJ), a solo 5th at the covid-delayed Winged Foot U.S. Open, and a solo second to Jason Kokrak at the CJ Cup @ Shadow Creek (a leaderboard absolutely littered with current LIV players).

Top 10 (see all)
Player	DG		OWGR
Scottie Scheffler	1	—	1	—
Xander Schauffele	2	—	2	1
Rory McIlroy	3	—	3	1
Ludvig Aberg	4	—	6	—
Collin Morikawa	5	2	9	4
Viktor Hovland	6	7	5	2
Jon Rahm	7	2	7	2
Russell Henley	8	2	16	1
Joaquin Niemann	9	1	88	3
Bryson DeChambeau	10	10	35	89
Notables
Justin Thomas	15	4	24	7
Sahith Theegala	16	2	12	—
Alex Noren	18	3	53	6
Harris English	26	10	45	2
Billy Horschel	37	14	64	5
Shane Lowry	39	14	33	10
Dustin Johnson	57	2	345	47
Ryo Hisatsune	83	26	85	3
Harry Higgs	436	—	239	—

After winning the 2022 PGA Championship Justin Thomas went on a horrible run at the majors. In the 7 starts following that win he lost 0.8 strokes per round, with his best finish being a T37. Last week Thomas snapped this poor run with a T8 in front of his hometown fans (despite a wobbly putter).

Jon Rahm dropped two spots in our rankings to 7th after missing the cut at Valhalla. From a strokes-gained perspective, it was the 5th-worst performance of his major championship career (this year's Masters was his 7th-worst). If we restrict to majors post-2018, his last two performances have been by far the worst of his career. Late last year we documented the troubles that the top LIV players have experienced after joining the #startup, calling it "LIV Fever"—Rahmbo might want to seek out a diagnosis.

Harris English underwent hip surgery in Febuary of 2022. After falling to 164th in our rankings last winter he has been slowly progressing back to the player we saw in 2020-2021. A T18 at the PGA Championship pushes his ranking up to 26th, the highest it has been since before the surgery.