If you ever watch Spieth and Greller interact, it is just great to watch. They talk, they listen, and Greller is always encouraging, keeping Spieth focused and confident. Consummate teammates, although obviously it is Spieth who ultimately swings the club.
And in press conferences, Spieth always speaks in the third person - “we” this, and “we” that, and clearly it is not a royal “we”. He fully embraces the concept of team, and fully understands that it is not just him out there making shots. His success is the culmination of many people’s inputs, not the least of which is Greller the caddie. I’m sure Spieth feels Greller is worth every penny.
And it won’t be long, if he isn’t there already, before his endorsement earnings surpass and ultimately dwarf his prize money earnings.
All very good points in your commentary on Spieth's team approach.
As to long term earnings, CBS Sports reported back in mid-summer that "Dan Patrick recently had a good debate on his radio show about whether Nike would trade Rory McIlroy to Under Armour to have Spieth. That the debate is even viable means that Spieth's Under Armour contract is probably in the ballpark of the $200 million one McIlroy reportedly received from Nike."