‘It wouldn’t pass the test’: Why Rory McIlroy retired his preferred driver

After Rory McIlroy’s strong play at the Arnold Palmer Invitational last week, it was easy to put him at or near the top of the list of favorites this week at the Players Championship at TPC Sawgrass. Then came Thursday, when he opened with a disappointing four-over 76 that has him 12 shots back of leader Chad Ramey.

After the round, as McIlroy was speaking to the difficulties he was having on the course, the conversation quickly turned to his driver, a TaylorMade Stealth 2 Plus that he added to his bag after the first round of the Genesis Invitational last month. Let’s break down what he was asked, and what he said.

Question: “I think the first day last week your driver was slightly off and you got it back. Is it something that you’re just not cracking on with your tee shot?”

McIlroy: “Yeah, obviously I went to that new driver in Riviera, and it’s just not…Look, I wish I could use my driver from last year, but I can’t just because of — you use a driver for so long, and it starts to get a little too…basically, it just wouldn’t pass the test.”

The test to which McIlroy is referring is the CT (characteristic time) test, which measures how fast or “hot” a driver’s face is. If the driver’s face is too fast, it can be deemed non-conforming/illegal.

When players use a driver for too long, it can become non-conforming by way of CT “creep,” which is what happens when a driver head gets repeated use, especially at higher speeds. The more the face flexes on impact, the more the metal — or carbon, in the case of McIlroy’s Stealth 2 Plus — starts to fatigue. Interestingly, as the face starts to fatigue, it doesn’t slow down — it actually gets faster, leading to more distance.

Pros’ drivers don’t often fail CT tests, but it does happen. Two days before the start of the 2019 Open Championship, Xander Schauffele’s Callaway driver failed a test and was deemed non-conforming by the R&A.

McIlroy is clearly attuned to driver regulations because he referenced the fatiguing process after his round Thursday, saying, “The more a club is used, the more it’s hit, the more springy the face becomes.”

At the Genesis Invitational last month, where the PGA Tour and USGA were on-site CT-testing drivers, McIlroy said he swapped drivers because he was concerned that his former first-generation TaylorMade Stealth might have been close to the limit. “I just didn’t even want to take the chance,” he said Thursday. “I just was not comfortable knowing that it could feel — doesn’t look good on me, doesn’t look good on TaylorMade.”

When reached for comment, a TaylorMade spokesperson said in a statement, “We constantly monitor the performance of our products on all tours and work with our athletes on the best timeline to consider any optimal changes. This is a normal and regular process.”

Although driver talk consumed most of McIlroy’s post-round press conference, he still placed blame on himself for his poor play and noted one of the benefits his new driver has provided since he made the switch.

“This one is as close as it’s been (to the previous driver),” he said. “Yeah, there’s obviously a part of it that’s the user, as well. It’s quite a lot of user error in there, as well.”

When asked if his new driver showed a tendency off the tee, McIlroy said, “If anything there’s not a lot of left in it, which I like. Historically, my miss off the tee has been left, so it’s nice to know that you’re sort of taking, I guess, that side out of play.”

The upside for McIlroy on Thursday: He still gained +.704 strokes on the field with his driver, putting him inside the top-20 in that category. He actually struggled more with his short game and putter, where he was -3.181 around the greens and -2.628 with his flatstick. McIlroy is three strokes off the current cut line and in need of a big second round if he is to give himself a chance this weekend.

Looking to gain some distance and confidence off the tee with your own game this season? Find a fitting location near you at GOLF’s affiliate company True Spec Golf. For more on the latest gear news and information, check out our latest Fully Equipped podcast below.