The unflappable American rarely shows any hint of emotion, even when he won last year's PGA Championship to capture his first Major title.
In the opening round of the Masters on Thursday, Dufner's easygoing nature was put to the ultimate test when he took nine shots to complete the par-five 13th hole, statistically one of the easiest holes on the course.
Dufner was in a great position to at least par the 510-yard hole when his second shot landed just off the back of the green.
But he hit his chip a little too firmly and the ball rolled off the front side of the green and down on to a grassy bank near Rae's Creek.
Then he hit his next chip too softly and the ball fell backwards past his feet and into the water hazard, forcing him to take a penalty.
He needed two more chips to get on the green and two putts for a quadruple-bogey, offering no more clues to his mental state than a wry smile and a shrug of his shoulders en route to an opening-round 80.
"The margins are very small," Dufner told ESPN. "Miss a shot and you're going to make a bogey or a double ... or in some cases a nine."
- Sports & Recreation
- Jason Dufner