Perhaps you heard: Rory McIlroy is using a new driver head this week at the PGA Championship.
McIlroy switched from his previous gamer, a TaylorMade Qi10 (DOT), to another identical model that was his backup. Normally, this wouldn’t be much of a story, but since it’s McIlroy, the No. 2 player in the world who just completed the career Grand Slam, it’s news.
Here’s what we know
No. 1: McIlroy hasn’t spoken on the topic yet this week, but we know he switched heads because we photographed McIlroy’s driver last week in Philadelphia (left, below) and there was an obvious wear mark on the sole of the club. The driver McIlroy has been using at Quail Hollow (right, below) does not have the same blemish.
No. 2: McIlroy’s driving took a big step backward Thursday. He leads the PGA Tour in strokes gained: off-the-tee (.869) by more than a tenth of a stroke and was second in the category at the Truist Championship last week. In Round 1 at Quail Hollow, McIlroy gained just .037 strokes off the tee, and missed three consecutive drives on 15, 16 and 18 left, narrowly missing water each time and leading to a double bogey on 16. After an opening 74, McIlroy looked more like himself on Friday, gaining 1.268 strokes off the tee on his way to a 69 to make the cut on the number, although he still hit only 10 fairways in the first two rounds.
No. 3: We still do not know exactly why McIlroy had to switch drivers. On Friday afternoon, during McIlroy’s second round, SiriusXM reported that McIlroy’s old driver head had been deemed “no longer permissible.” Host Taylor Zarzour said: “[McIlroy] was not able to use it this week — his gamer, if you will. It was deemed to be no longer permissible. Whether it was cracked or something had happened to the head. Rory [was] unable to use that driver and switched drivers yesterday…” SiriusXM staffer Jason Sobel later tweeted the driver had been deemed “non-conforming by the USGA.” The USGA oversees driver testing this week at Quail Hollow, just as it does at PGA Tour events, with 30 players being selected at random.
Neither the USGA nor the PGA of America has confirmed that McIlroy’s driver failed a test, citing the confidential nature of its testing process. The players themselves are free to discuss test results, as Xander Schauffele did at the 2019 Open Championship when his driver was deemed nonconforming. McIlroy declined media interviews on Thursday and Friday.
Kerry Haigh, the PGA of America’s chief championships officer, released a statement Saturday afternoon confirming the USGA testing, but he did not name names. The statement reads:
“That testing program is consistent with the same level of support that the USGA provides to the PGA Tour and other championships, as part of their regular programs for driver testing. The standard process is for about a third of the field to be randomly tested under the program. That was the case at Quail Hollow this week. Finding driver heads that have crept over the line of conformance is not an unusual occurrence, especially for clubs that are hit thousands of times over a long period of time.
“The results are kept confidential to protect players, who are unaware the club has fallen out of conformance and not responsible for it falling out of conformance other than hitting the club thousands of times. Players are simply asked to change heads if necessary, and all do without issue. To publicly identify players whose club did not conform can lead to that player being questioned unnecessarily. Neither the USGA nor the PGA of America have any concerns about player intent.”
Driver faces pushing up against the legal limit is not a concern for the players in your Sunday foursome, but for mashers like McIlroy, who repeatedly bang their drivers in the same spot at 125+ mph, the face will inevitably thin out over time and possibly even crack or cave in. For McIlroy, he likely has been playing the Qi10 head with which he won the Masters for several months, if not longer.
All clubs eventually wear out. Pros change wedges as frequently as every few weeks and change iron sets once or twice a year. Interestingly, wear makes drivers perform better (or at least faster) while other clubs perform less well due to a lack of spin.
Random testing by the USGA for drivers in play was introduced for the 2019-20 season, and players were selected based on Darrell Survey information, meaning there would be a representative sample of manufacturers based on how many drivers each manufacturer had in play.
How to know when a driver is approaching legal limit
The driver heads you’ll find on a tour truck at a PGA Tour event are marked with the CT (Characteristic Time) with which they came out of the factory. Tour reps actually cherry-pick heads for pros that are slower than the ones available at retail to prolong the decay of the face.
Still, all faces wear down.
Tour players’ drivers fail conformance tests more frequently than you might think; most players will simply pop on a new head and go on with their weeks. No big deal. Ping tour rep Keanton Oates told GOLF.com that switching heads on the fly was more challenging 10 years ago, but with the advances in fitting, it’s become easier to have two or three backup heads at the ready.
Callaway tour rep Kellen Watson told GOLF.com that Jon Rahm failed a test before the 2023 Genesis Invitational and still went on to win that week.
The pros may not know when a driver face is pushing up against the limit, but the equipment reps know the signs — i.e., when ball speed starts increasing and spin drops.
“You’ll see some of what the pros say are ‘funky shots,'” Watson said. “Right out of the middle, going right and not spinning at all or right out of the middle, going left and not spinning at all. It’s just the breakdown of the material over time.”
All of the Tour trucks are armed with the same CT-testing machines the USGA uses so they can quickly determine if a driver needs to be replaced before any test.
Watson said after two to six months of regular play, there’s nothing you can do to mitigate the risk of failing a CT test. And that’s no commentary on how well a driver is made or what materials it’s made of, either.
Watson used the example of giving an MLB power hitter like Shohei Ohtani a metal fast-pitch softball bat.
“It could take three swings and that thing will be completely broken,” he said. “So there is a decay of the material. The longevity of the metals is never going to last.”
This is where a pro’s backup driver becomes crucial.
Watson said McIlroy was dealt a particularly bad hand this week, regardless of why he swapped out heads. Not only is it a major week but the poor weather in Charlotte and limited practice time likely also made it difficult for McIlroy to get comfortable with his backup.
That comfortability, Watson said, is crucial. Watson said when Rahm failed that test at the 2023 Genesis, he and Rahm thought the backup was dialed on Wednesday afternoon, but when the tournament began, it was a different story.
“He played amazing with his irons and putted great to win that tournament,” he said.
Another factor to keep in mind, said Oates, the Ping rep, is that 3-woods, which aren’t tested by the USGA as regularly as drivers, can actually become “hot” just as quickly as drivers.
“We actually have to keep an eye on 3-woods because of the smaller heads and the way these guys hit them into the turf,” Oates said.
Players are still swinging 3-woods upward of 110 or 115 mph, and how they interact with the turf can expedite the face-thinning process. The smaller heads also offer less face support, which can lead to cave-ins.
Bottom line
Whatever the reason for McIlroy’s swap, he’s had a short window to get comfortable with a new head — and that seemingly led to some big misses off the tee Thursday that set him back as he chases his second major title of the season.
McIlroy did not violate the rules or play a driver that was deemed nonconforming. Nor is this any fault of TaylorMade’s.
It’s simply a result of what happens when you have a player who smacks a golf ball with a carbon or metal object thousands of times at 125 mph.
Give McIlroy time with his new gamer — he’ll be just fine.
Johnny Wunder contributed to this report.
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