Want to know the secret of Tiger Woods' success?
According to Butch Harmon, who coached the former world No.1 between 1993 and 2003, it's pretty straightforward.
It's because he's an "arrogant p***k".
Speaking with his son and fellow top coach Claude on Instagram, Harmon outlined the singular mindset that set Woods on the path to winning a record 82 times on the PGA Tour - 15 of them majors.
“You absolutely need a streak of arrogance to be a great champion, to be the best at what you do," said Harmon. “You’ve got to have a lot of p***k in you. You have to be that kind of guy when you walk between the ropes.
"Tiger’s definitely that way. Guys like him just want to cut your heart out. They’ll go to dinner later on, or we’ll have a beer afterwards and joke. But when it comes time to play, I’m going to really get you.
Harmon added that this is by no means a trait exclusive to Woods.
“A certain Jack Nicklaus thought that way, too. He had that dose of arrogance you need. But you would never know it by his demeanour.
"Tom [Watson] was the same way, although, like Jack, you’d never know it by his demeanour. But they had it. They knew how good they were."
Of the current crop of players, Harmon says that he says those same qualities in two players that he and son Claude have both coached: Dustin Johnson and Brooks Koepka.
“You and I know DJ as well as anybody. He is so laid back, but when he walks between the ropes he changes. Brooks is the same way. They just want to beat you so bad. It’s what drives them.
“In Brooks’ case, I still don’t think he gets the credit for being as good as he is, even though he’s won four majors in the last few years."