Jordan Spieth is having one of the best seasons in PGA Tour history, and, as a direct result, so is his caddie, Michael Greller.

In 19 events so far this season, Spieth has 12 top-10 finishes and five wins, including the Masters and US Open. That has added up to $9.7 million in winnings and $8.7 million on the official Tour money list*. The latter is more than twice as much as anybody else on the Tour this season.

Caddies are traditionally paid 5% of the prize money for making a cut, 7% for finishing in the top 10, and 10% for winning a tournament according to Golf Digest's "undercover pro." If Spieth is using the same structure, his success on the golf course this season translates to a share of $866,534 for Greller. That would be enough for Greller to rank 93rd on the PGA Tour money list this season, ahead of 159 PGA Tour members.

Greller quit his job as a teacher in 2013 to caddie full-time for Spieth. He is probably happy with that decision.

*Jordan Spieth won $1 million for finishing first at the Hero World Challenge. While it is an official PGA Tour event, the winnings do not count towards the official money list, as there are so few players who compete (18 this year).