Greller, 36, gave up a 10-year profession in education to become Jordan Spieth's full-time caddie. What Greller called an educated risk at the time has turned into a goldmine.

That's not how Spieth operates. Article continues below this ad “It's really hard to get me to chip out,” Spieth said after he opened with a hard-earned round of even-par 72 at Muirfield Village.