The golf players not only play the game on the course, but also in their minds. Since 2007, when Tiger Woods' former swing coach, Butch Harmon, started working with Phil Mickelson, Mickelson has established an 8-3 record against Woods when the two are paired together in a tournament. After Harmon started coaching Mickelson, he explained to Mickelson the "psychological warfare" Woods used against him, and how to counteract Taylormade RocketBallz RBZ Irons.