Chris Carlson/Associated Press

The average compensation of someone 15 years into a teaching career in Seattle is $77,498. Michael Greller, who gave up his teaching job in the Seattle area to caddie full time for 2015 Masters champion Jordan Spieth, has likely more than quadrupled that total in the last 30 days.

Using a rough calculation of typical caddie-golfer contracts, Tony Manfred of Business Insider estimated that Greller has made about $375,000 as Spieth has rocketed up the Official World Golf Ranking this past month. Spieth, 21, matched the 72-hole scoring record at Augusta at 18 under and became the first wire-to-wire winner since 1976 with Greller at his side.

Manfred wrote of Greller's earnings:

While we don't know the exact details of Greller's contract with Spieth, it's fair to say he's making more now than he could have teaching. According to Golf Digest's Undercover Pro, caddies on the modern PGA Tour typically get paid a base salary for $1,300-$1,800 per week with additional results-based bonuses. Traditionally, that bonus structure is 5/7/10 (5% of winnings for a made cut, 7% of winnings for a top-10 finish, and 10% of winnings for a tournament win). In the last 30 days Spieth has two second-place finishes and two wins, including the Masters (a $1.8 million prize), for a total of $4.1 million in winnings. Under the traditional rates, Greller stands to have made $375,000 in performance bonuses alone during that period.

Greller, who first caddied in 2006, began working with Spieth at the U.S. Junior Amateur in 2011. Greller initially planned to take a one-year sabbatical from his job as a sixth-grade math and science teacher but left to be Spieth's full-time caddie in 2013.

Brian Costa of The Wall Street Journal reported on how rare Greller's story is:

But in hiring Greller, 37, at the start of Spieth’s career and sticking with him as he ascended to this point, Spieth prioritized personal chemistry. That he went so far as to hire someone who had caddied only occasionally for amateurs ranked as one of the bigger upsets in pro caddying. “It’s rare,” said Mike Kerr, a PGA Tour caddying veteran who now caddies for Adam Scott. “You have to be really lucky to get into that position. But the way they work together, it looks like he’s been doing it a long time.”

But Greller appreciates his situation.

"I thought three years ago was the pinnacle just being out there walking around." Greller said, per Teresa M. Walker of The Associated Press, of his experience at the event as a spectator.

"Being here two years later, that was pretty surreal, and I think that was the best thing that probably happened to us not winning it, and certainly all that experience came into play all week, and especially today," he said of his experience with Spieth at last year's event.

Spieth set 36-hole and 54-hole scoring records en route to his first green jacket, taking advantage of ideal course conditions to defeat Phil Mickelson and Justin Rose by four strokes. A bogey on No. 18 Sunday was the only thing that kept him from breaking Tiger Woods' event record, which he set in 1997 on his way to his first of four green jackets.

Charlie Riedel/Associated Press

Commenting on the role he plays for Spieth, Greller categorized himself as more of a mental springboard than an on-course technician. He said most of his job involves keeping Spieth focused when things start to go haywire, per Walker's report:

If he needs to let things go, I'm the person who's going to bounce it off of him. Just being able to adapt to situations I think that's certainly something from teaching school for so long you have to do out here. You have to be able to adapt week to week, day to day, today hole by hole with the wind doing what it's doing.

The formula has worked. Sunday was Spieth's third victory of the PGA Tour season and his second top-two finish in as many Masters tournaments. The Texan is now the world's second-ranked player behind Rory McIlroy, with whom he'll likely compete to be the face of the sport for the next decade.

As for Greller, whatever the result of the impending McIlroy-Spieth battle, it sure beats third-period math and cafeteria duty.

Follow Tyler Conway (@tylerconway22) on Twitter.