ATLANTA, GA - SEPTEMBER 22: Phil Mickelson hands his Callaway driver featuring a new True Temper Project X HZRDUS T1100 shaft back to caddie Jim "Bones" Mackay on the 18th hole tee box during the first round of the TOUR Championship, the final event of the FedExCup Playoffs, at East Lake Golf Club on September 22, 2016 in Atlanta, Georgia. (Photo by Keyur Khamar/PGA TOUR)
