Speaking ahead of the 2016 U.S. Open, South African Charl Schwartzel said Oakmont's putting surfaces "are more difficult" than the ones at Augusta National, home of the Masters.
"Augusta has big slopes but they are gradual, almost constant in a way," Schwartzel told Reuters. "Here you've got big slopes that have four breaks. The ball comes off a break and it will turn the other way and it will go back the other way and then down a hill. There are so many more variables here."
For his part, Schwartzel said he was excited about the strategic challenge that Oakmont poses.
"This really, really shows the weakness in your game if there is anything," he said. "And it even shows the weakness in your mind, if there is anything like that too."
Schwartzel is ranked 22nd in the world and already has wins on the PGA Tour and European tour this season. When he last competed in the U.S. Open at Oakmont in 2007 he finished T30.