Rory McIlroy is good from the tee box.
Like, really, really, really good.
The players know it - they regularly attest to his quality in that part of the game - and the numbers back it up: he's never finished outside the top six in the PGA Tour's Strokes Gained Off the Tee seasonal rankings.
However, he didn't hit it very well last week at Liberty National. He ranked 27th in the field and it had a blistering effect on what happened next: 72nd for SG Approach, comfortably his worst effort of the year.
It emerged that there were two problems - one technical, the other the test - and, on the evidence of a superb 8-under-par 64 to open the BMW Championship, both have been fixed.
"I went home to Florida after The Northern Trust on Monday night," he explained after tying Sam Burns and Jon Rahm for the first round lead. "I went into the garage and rummaged through a few different things."
If most of us had a rummage in the garage we might find a reckless purchase from the garden centre or a match day programme from the 1980s. McIlroy discovered something more substantial.
"I found a 3-wood," he said. "My new old 3-wood, a 3-wood I used last year. Got my old putter back out, too. And went for a new shaft in the driver. It seemed to work out today."
In those first 18 holes he ranked second for Strokes Gained Off the Tee which helped him land seven birdies and an eagle-3 at the 16th.
But there was more to it than the equipment: the Tom Fazio design at Caves Valley Golf Club also played into his hands.
"It lets you hit driver, first and foremost," he said. "There's a lot of courses we play nowadays where a lot of fairways pinch in at 300-yards. It doesn't allow the long hitters to hit driver a lot, last week being a pretty good example of that.
"Whenever you get a big golf course like this that allows the big hitters to hit driver, that's usually a big advantage. It's just nice to feel like you can let it fly a bit."
Nor was it just at the start of every hole that he was making gains. That new old putter was hot.
"It felt so easy," he said. "Felt like I couldn't not start it on line. It was sort of there's a lesson in there somewhere about maybe just keeping a blade putter at home and practising with it, then coming out here and putting with something that's got a little more technology in it."
And what of his energy levels, after his frequent pre-tournament references to fatigue?
"I was super tired yesterday," he admitted. "But you get a good night's sleep, you feel a little bit better the next day, you can go out and play well.
"Another good night's sleep tonight, get up, get back out on the golf course and try and do the same stuff that I did today."
Let's take a quick look at McIlroy's past performance from this sort of position and what his fellow leaders had to say.
Second Off the Tee, he was also third in SG Putting during the first round. A slight concern remains about his Approach work - he was only 25th in the field.
And how has he responded to a fast start in the past? It's the 29th time in his career that he's landed an 18 hole lead and he's converted the win five times.
The next point is kind of obvious: when he's taken an early lead, he's never gone lower in round two and only twice equalled his first round score.
He's 12-for-28 at shooting a number in the 60s in round two from this position, but has done it just once in his last six instances.
Finally, what has he scored in round two when grabbing the lead with a 64? It's arguable what merit there is in these numbers, beyond curiosity, but for what it's worth he's carded 68, 69, 68, 78, 71 and 72.
He, Rahm and Burns lead Sergio Garcia by one, with Abraham Ancer and Patrick Cantlay a further shot back in a tie for fifth.
So he's found 13 of 14 fairways, biffing it with the driver, and the approach work is so-so. What happens if he doesn't find so much short grass? Add in the difficulty of repeating and maybe he's worth taking on in round two? Playing partner Sungjae Im carded a 67 in round one.
Jon Rahm on the secret to rebounding from a bad round
"For all those Ted Lasso fans out there, be a goldfish. If you haven't seen the show, you've just got to check it out. I feel like almost everybody knows. Have you seen the show? Basically the happiest animal in the world is a goldfish. You know why? He's got a 10-second memory. The best goldfish out here? Oh, without a doubt Dustin Johnson. He has the ability to forget unfortunate moments better than anyone else."
Sam Burns on his caddie's smart
"We had a good plan coming into today. (My caddie) Travis and I talked about it. Really just it was nice being able to touch it in the fairway and then just trying to put it in the right spot on the green. I think that's the biggest thing around this place: the greens are big but you can have 20 feet and still have it breaking six feet, so trying to avoid those areas, give ourselves the easiest putt, and we were able to make them.
"Travis was out here early Tuesday morning and every week he's very intentional about seeing stuff around the golf course, seeing certain things that I obviously look over. It's just that little stuff about certain tee shots where I'm thinking the right bunker is no good, and he's like, right bunker is totally fine. Like, 14 or 15 today, I hit it in the right bunker and it was 30 or 40 yards closer from there and you're hitting a 9-iron in. If you hit it in the left rough you're hitting probably a 6-iron out of the rough. Just little stuff like that that he's done is really helpful."