On Tuesday Xander Schaufelle’s Callaway driver failed a random R&A test, which was introduced at the 2018 Open Championship. A 20% sample of the 156 field had their clubs tested to see if they complied with what is called the co-efficient of restitution. This is a measure of how much energy is transferred from the club to the ball at impact, which has to be up to 83%. Also tested is how long the driver face  and ball are in contact, which has to be less than 239 microseconds. Tiger Woods was also among the random sample, and his equipment passed. It is the first time a player’s equipment has failed this test.

Speaking on Friday Schauffele said

“Yesterday it wasn’t really matching my bag, which was a bummer. I was getting a little upset on the golf course,” Schauffele said. “Today I was testing a little bit on the range again with two different heads. But moved a few weights around and sort of found a good setting.”

I have a legal driver now, and I sort of put that one to rest and happy to see that ball performing like it did today or the driver performing like it did today, so that was very comforting,” he said. “Like I said it will get better every day. We’ve still got two more.”

“I had a little bit of run-in with them, because they only test 30 players. I thought it was a little bit unfair,” Schauffele said after his Callaway Epic Flash Sub Zero was dinged on Tuesday. “I would gladly give up my driver if it’s not conforming. But there’s still 130 other players in the field that potentially have a nonconforming driver as well.”

On Friday Schaufelle shot 65, the best score of the day and is currently -4 for his round on Saturday, three birdies in four holes within one shot of the lead.

A reporter for Golf Digest has observed this

“Update on the Xander/driver controversy. Multiple sources tell Golf Digest Schauffele may not have been the only player to fail the CT test, with 3-to-4 manufacturers at fault. Asked about other failed tests, the R&A told us it wouldn’t comment further on the process”