– Jordan Spieth had to change his head. He cracked the face of his driver Wednesday and was forced to replace it before the Masters began, the kind of last-minute alteration that can spook a golfer.

He had to change his mindset, too. He hadn’t finished higher than ninth in his previous six tournaments, missing one cut, a record that would not have been considered disappointing if he hadn’t raised expectations by becoming golf’s player of the year as a 21-year-old in 2015.

Thursday, Spieth shot a first-round 66 in high winds at the Masters, taking a two-shot lead and providing a reminder that some competitors can flip a switch or switch a head and surge when the right trophy is within reach.

With one green jacket already, Spieth seems eager to make the Masters his own personal haberdashery. Consider these milestones:

• He has shot a 66 or better in three of his last five rounds at the Masters. The rest of the field has combined for four rounds of 66 or better.

• Spieth is the first player in Masters history to hold the outright lead after five consecutive rounds.

• In his first nine rounds as a professional at the Masters, he is 29 under. In Tiger Woods’ first nine rounds as a pro here, he was 21 under.

• His 66 tied him for the record for the lowest opening round by a defending champion in Masters history, with Jose Olazabal in 1994.

• Spieth is trying to become the first player ever to successfully defend a major title at the age of 22 or younger.

• He is the fourth defending champion in Masters history to hold the outright lead after the first round. The last to do that: Jack Nicklaus in 1966.

He has never been over par at the Masters.

(Some statistical information provided by Justin Ray of the Golf Channel.)

“I enjoy this tournament more than anywhere else,” Spieth said.

Masters leaderboard

Spieth sounded unhappy with the performance of his driver. He averaged 262 yards on driving holes — 36 yards shorter than Sergio Garcia and only a yard or two better than Mark O’Meara and Ian Woosnam.

He said he wasn’t particularly happy with his iron play, either.

He putted so well that he nevertheless made six birdies and no bogeys.

“I put it up there with one of the best rounds I’ve played — one of the best rounds I’ve scored,” he said.

Spieth is trying to join Nicklaus, Nick Faldo and Woods as winners of consecutive Masters. He is trying to become the 18th player in history to win multiple Masters. To reach those milestones, he will preview the role he may play in September at Hazeltine. He is about to take on the cream of the European Ryder Cup team.

Justin Rose, Ian Poulter, Garcia and Rory McIlroy are all tied for ninth or better.

The Augusta National “patrons” have embraced him. The crowds around him are remindful of those that followed Woods in his prime, and his playing partners are beginning to speak in the awed tones of those who found themselves discombobulated by Woods’ massive galleries.

“I was impressed with everything today,” said Paul Casey, who played in a group with Spieth and Bryson DeChambeau. “That was a flawless round of golf.

“One of the toughest days I’ve ever seen around Augusta National. I played a wonderful round of golf, but it was great to have a front-row seat to watch that.”

DeChambeau walked with Spieth to the 18th green. “He loves the greens,” DeChambeau said. “He said, ‘I don’t know what it is about this place, I just love putting here. I can see the break, I can see the lines.’

“I was quite impressed with that.”

Spieth relies on Ben Crenshaw for advice on putting Augusta National’s subtle greens. He and what he calls “my team” try to ensure he peaks for majors.

What is most important for Spieth, and at the Masters, is this:

Spieth’s best club is the only one built specifically for knocking the golf ball into the hole.