How Brad Stevens transformed from a college basketball assistant making $18,000 a year to one of the best coaches in the NBA

The turnaround has been stunning — the Celtics lack any traditional stars, and when they hired Stevens from Butler, they were supposed to be tanking.

Instead, Stevens has built a system of selfless, motion basketball that has turned a 5-foot-9 point guard in Isaiah Thomas into a dynamic scorer and turned a team of role players into one solid unit.

The NBA world has taken notice, as a former assistant-turned-head coach in college is beating NBA coaches at a level nobody expected.

Here's how Stevens has risen from an assistant making $18,000 a year collecting film to one of the best coaches in the pros.

Stevens was a high-school basketball star in Indiana, but received only one Division I offer after high school. He chose instead to play DIII basketball at DePauw University.

Source: ESPN

Stevens was hardly a star in college. He averaged just five points per game his senior year and struggled to accept a role off the bench, playing behind underclassmen.

Source: ESPN

When Stevens graduated, he had accepted a high-paying job at pharmaceutical company Eli Lilly.

Source: New York Times

Stevens, however, was upset about leaving basketball. He coached a summer camp at Butler after graduating, then accepted an offer to become a volunteer assistant for the men's basketball team in 2000.

Source:New York Times

Stevens took up a job at Applebee's to make money while volunteering. But the day before training, he was promoted to director of basketball operations because an assistant coach was arrested for soliciting a prostitute (charges were later dropped).

Source: New York Times

Stevens made just $18,000 a year, spending about 14 hours a day logging footage of defensive tendencies. Stevens called it, "as enjoyable a year as I ever had."

Sources: ESPN and New York Times

In 2007, Stevens was promoted to head coach of Butler after previous head coach Todd Lickliter left to coach the University of Iowa. Butler went 30-4 in his first season as head coach.

During the 2009-10 season, Butler went 33-5 and made an impressive run to the NCAA Tournament to reach the championship game.

In the championship, they lost a classic to Duke, falling 61-59, as Gordon Hayward's halfcourt heave missed at the buzzer.

The following season, Stevens and Butler went 28-10 and made another run through the NCAA Tournament. They eventually lost the championship game to Connecticut.

Stevens coached two more years at Butler, going a cumulative 49-26. Along the way, several schools tried to poach him, with UCLA most notably offering him as much as $3 million per year. Stevens reportedly made as much as $750,000 in 2010 with Butler.

Sources: LA Times, Indy Star

However, it was the Celtics that pulled Stevens away from Butler in the summer of 2013 with a six-year, $22 million offer.

Source: ESPN

After going 25-57 for the rebuilding Celtics in his first year, Stevens and the team hit a stride after trading for Isaiah Thomas in 2014. In the last two seasons, the Celtics have gone 101-63 while Thomas has become an All-Star.

The Celtics finished first in the East in 2016-17, going 53-29. They advanced to the Eastern Conference Finals, and shockingly won Game 3 over the Cleveland Cavaliers in Cleveland on Sunday, even with Thomas out with a hip injury.

Celtics Blog recently dubbed Stevens an "ATO [After Timeout] Genius" for his clever inbounds plays. The game-winner he drew up for Avery Bradley in Game 3 was impressive.

The Celtics have perhaps the brightest future in the NBA, thanks in part to Stevens. He's proven he can win with any amount of talent, and they have this year's No. 1 draft pick and cap space this summer. The Celtics are considered a landing spot for Hayward because of his connection with Stevens.

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