Ryen Russillo says Tristan Thompson is good at so many different elements of offense and defense. (1:16)

When Byron Scott first met his Cavaliers team in the fall of 2011, he gave each player a 5-by-8 note card with written instructions outlining his role. The card for Tristan Thompson, a prized rookie, was simple: set screens, rebound, talk on defense, have "a high motor." It did not mention scoring.

Scott asked each player to read his card, absorb it and come back with suggestions. "Tristan was the only guy who just said, 'That's all good, Coach,'" Scott said.

This was a big reason the Cavs nabbed Thompson with the No. 4 pick in 2011 in what critics labeled a reach. Thompson was the rare prodigy who knew what he was and what he wasn't. "I don't think we ran one play for him," said Rodney Terry, an assistant at Texas during Thompson's one year there, and now the head coach at Fresno State.

In studying prospects, the Cavs understood a grinder like Thompson would look bad in agent-controlled one-on-one sessions. They invited Thompson back for a second pre-draft workout in which he would play three-on-three against a team featuring Enes Kanter and Derrick Williams, only they neglected to tell Kanter about the three-on-three part, sources said. Kanter arrived expecting to go one-on-one against a patsy. Instead, Thompson destroyed both players in a game-like setting. "He just would not let them score," said Pete Babcock, then a Cavs scout. Thompson knew Williams and Kanter were projected ahead of him and wanted to show, in his own way, that he was better. Editor's Picks NBA draft 2017: Key dates, news and analysis

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"They had no chance," Thompson said last week in Boston. "I love proving people wrong."

Still: The Cavs worried Thompson was too unskilled with the ball. They might have drafted Jonas Valanciunas had he committed to leaving Europe for the NBA at a specific time, sources said. By draft night, they felt fine taking Thompson. They saw a player who understood his limitations and thrived on the fact that people doubted him because of those limitations. He would not use criticism as fuel to become a different sort of player. He would become the very best version of himself: an elite role player.

"You were drafting character and toughness and someone who had great perspective on what he could and could not do," Babcock said.

That is not to say he lacked the usual ambitions. Samardo Samuels, who played with Thompson in high school and during his first years in Cleveland, said Thompson would sometimes ask: "Was I worth the fourth pick? Should I score more?" Mike Brown, who coached Thompson in 2013-14, said he would call plays to appease him.

"His first couple of years, he might try some things that weren't really his game," said Jai Lucas, who played with Thompson at Texas and remains close with him.

The Cavs didn't mind Thompson's exploration. They stunk anyway, and he stayed mostly within himself. The only statistical goals he ever mentioned were averaging a double-double, or snagging five rebounds per quarter, coaches and teammates said.

And for Thompson to reach his potential, he would have to get more comfortable with the ball. He needed a floater, a better free throw stroke, the ability to pass inside-out and to kick his maddening habit of bringing the ball down between his knees after offensive rebounds. In his early years, Thompson had his shot blocked more than any other player.

Six years later, he has found the perfect balance and stands as a crucial two-way player uniquely suited to closing the talent gap with Golden State. He still cares most about rebounding and defense, especially harassing guards on switches. Coaches gleefully recall Thompson strutting to the bench after forcing Stephen Curry into a long miss during last year's Finals, exclaiming, "I told you I don't need no help!"

They flashed back two years, when Derrick Rose banked in a buzzer-beating 3 over Thompson to clinch Game 3 of the conference semifinals:

Thompson was inconsolable. When the Cavs gathered for their postgame huddle in the locker room, Thompson wasn't there. He was weeping in the showers. It took Mike Miller and James Jones to drag him out. "That's who Tristan is," Miller said. "You don't win championships without guys like him."

"No kid wants to grow up and be Tristan Thompson," said Rick Barnes, who coached Thompson at Texas and is now at Tennessee. "But if they knew what coaches knew, they might."

A year ago, Thompson guarded every position and tossed people out of the way for offensive rebounds. He has become one of the league's meanest, canniest screeners. He also surprised the Warriors by hitting several soft-touch floaters, a shot he honed by watching film of Al Jefferson, he said:

Defend LeBron James and all that shooting for 20 seconds, and here comes Thompson to extend the possession, or end it with a shot that might make the bottom of the last page in a scouting report. He is perhaps the most demoralizing player in the league, and there might be no more demoralizing NBA moment than Thompson hitting a floater at the end of the shot clock.

"I get it," Thompson said, laughing. "I'm last on the checklist. That's fine with me. I love seeing all the energy and hope come out of the other team."

"Everything he does," said Raptors coach Dwane Casey, "is so deflating."

When Kyle Korver arrived in Cleveland, he said he approached Thompson and told him, "Man, I'm so glad I don't have to play against you anymore."

Thompson obliterated Korver's Hawks in the 2015 and 2016 playoffs and created dissension among them. "He made Paul Millsap disappear," said David Blatt, the former Cavs coach.

Atlanta's big men so feared Thompson's offensive rebounding, they became hesitant to leave him and contain drives. The guards, hung out to dry, snapped at the bigs. The bigs snapped back that they needed more rebounding help. "He just becomes this problem," Korver said. "Everyone is suddenly yelling at everyone else. You get a stop against LeBron, and he gets another rebound. It's so frustrating. It sucks all the wind out of you."

A few weeks after the Cavs won the title, Thompson reported to the Canadian national team ahead of Olympic qualifying. He asked the coach, Jay Triano, if he might have five minutes to address the team. Triano was curious. Thompson was a champion and a celebrity. Had he lost his sense of self?

Thompson talked about everyone accepting their limitations and playing their role even if it was mostly grunt work. He would play the same way for Team Canada as he did alongside LeBron, Kevin Love and Kyrie Irving. "He's the same guy for us," Triano said.

He has always been the same guy. "The only thing that changed," Lucas said, "is his bank account. And maybe who he dates."

Thompson was an atypical teenage star when he arrived at St. Benedict's Prep in Newark, New Jersey, to play for Danny Hurley, now the coach at the University of Rhode Island and the son of legendary St. Anthony coach Bob Hurley. "He was a little bit of a disaster," Hurley said. "He couldn't shoot or dribble. His shooting mechanics were so bad with his left hand that it was clear he would have to start all over."

Hurley had two incumbent starting bigs, including Samuels, so he played Thompson at small forward. The team's offense amounted to throwing the ball up and hoping someone could dunk it or snare an offensive rebound.

Hurley played a 1-3-1 zone on defense and used Thompson at every point of it. "He is the best defensive player I've ever witnessed," Hurley said. Thompson never demanded the ball on offense. "He was never delusional, and I've had a lot of delusional kids and families," Hurley said.

Thompson was already 6-foot when he started playing serious basketball in seventh grade, and his youth coaches say being the biggest kid on the court honed his sense of self. He never knew what it felt like to play guard and dance with the ball. "Our teams always won, and Tristan saw how he could impact winning doing big man things," said Tony McIntyre, Thompson's youth coach in Toronto. "Everything he does now, even the way he tips the ball to himself and sticks his elbows out, he was doing that back then."

Thompson spent weekends at Hurley's house and became close with Hurley's wife and young kids. It shocked everyone when Hurley kicked Thompson off the team in 2009 after they argued at practice, a decision Hurley regretted almost immediately, he said. They did not speak for years. Even then, Thompson would call Hurley's wife to wish her a happy Mother's Day and check in on the children. (The courtesies persisted. When Thompson stayed at Babcock's family home in Newport one summer early in his NBA career, the family was stunned to discover he washed and dried all his sheets and towels. "What 20-year-old NBA player does that?" Babcock asked.)

Thompson transferred to Findlay Prep outside Las Vegas, a super-team that already sported Avery Bradley and Cory Joseph, Thompson's childhood friend. Michael Peck, the team's coach, was blunt with Thompson: "Don't come here and expect to be the guy." Thompson's agreeable response surprised Peck: "Coach, I wouldn't expect anything else."

Thompson, Bradley and Joseph were intensely competitive, and they held teammates accountable. Bradley dared anyone to beat him in a wind sprint. (No one could.) The trio staged their own free throw contests, with the winner getting the shower first when they got back to the home they shared.

Peck once forced the team to run extra after getting word that Nick Johnson, another star prospect who went on to Arizona, was slacking off in school. Afterward, Peck asked Thompson to intervene. Thompson jabbed his finger in Johnson's chest and exclaimed, "If we ever have to run extra because of you again, I will beat your ass," Peck and Thompson recall. They never did.

Joseph and Thompson attended Texas together and won the coaches over with their humility and work ethic. Thompson showed up overweight, and the coaches needled him, bestowing the nickname "Lil' Dex," after Dexter Pittman, the chubby ex-Longhorns center. They were testing Thompson. They knew he had been flabby as a kid.

In his early teen years, Thompson had been so intimidated by the few players his size, he sometimes hid in the locker room and refused to play against them. McIntyre had bribed him with promises of postgame Big Macs.

"For a little fat kid," McIntrye said, "that was really enticing."

The "Lil' Dex" nickname didn't stick. Thompson immediately tweaked his diet and shed pounds.

"Tristan and Cory are the only two freshmen I can ever remember who just got it right away," Lucas said.

Thompson never got tired in Texas games, coaches say. The Cavs believe he gets better in the postseason because off days allow him to go full throttle in every game.

Blatt calls Thompson the best fourth-quarter rebounder he has ever seen, and even asked the team's analytics department to try to prove it. The Cavs were among the first teams to install SportVU motion-tracking cameras, and they showed Thompson outworked everyone -- covering more ground, moving faster, maintaining higher speeds, Brown said.

But his lefty slingshot shooting form remained ugly. Barnes called it "the catapult." He filmed Thompson shooting righty at Texas practices to show him how much better it looked. He tried to convince Thompson to shoot free throws underhand.

By the end of the 2012-13 season, Thompson was already shooting most floaters righty. Scott had him toss footballs with either hand and found Thompson could throw the ball farther and more accurately right-handed. By the spring of 2013, Thompson was ready for an unprecedented overhaul.

Dave Love, Thompson's contracted shooting coach for the summer of 2013 -- "my summer girlfriend," Thompson joked -- had worked with lots of players. When Thompson told Love to be ready in the hotel lobby just before 8 a.m. for their first workout, Love figured he would show up at 7:30 and have plenty of time to sip coffee.

Thompson was already there, waiting.

That's how it was that summer, from Cleveland, to Toronto, to Florida, to Las Vegas, as they worked every morning to turn Thompson right-handed. They ate Chick-fil-A together, sometimes for breakfast, and once hit Chipotle 16 days in a row. Thompson sheepishly admitted to Love that he ate a dozen Tim Horton's donuts in one day.

They sprinted through Pearson International Airport in Toronto, minutes before flying to Orlando, Florida, because Thompson craved a Tim Horton's coffee and thought it would be exhilarating to risk missing the flight.

"It was a long run," Love said. "He gave no thought to how this might look to the public."

They even stopped in Miami for Game 6 of the Finals -- the Ray Allen game -- because James, who shares an agent with Thompson, suggested Thompson experience the intensity of the Finals firsthand. "LeBron said if I ever wanted to be a champion, I had to see what I was missing," Thompson said. He sat in the same seat for Game 7.

The work was fun, and easy, mostly because Thompson bought in on the first day. "A lot of players want to know why, or ask, 'How do I know what you are saying is right?'" Love said. "And that's fine. I like that pushback. But Tristan gave me his trust right away."

The results have been uneven, but broadly encouraging. Thompson's free throw percentage shot up from 61 percent the year before the switch to 69 percent in 2013-14. He slumped to 49.8 percent this season, the worst mark of his career, but has looked confident stroking 67 percent so far in the playoffs.

If teams load up on James and Irving, Thompson slips into the void for silky floaters:

If a third defender darts toward him, Thompson makes the next pass -- fast:

"Not a lot of big guys who start where he started can adapt like that," said Steve Nash, the general manager of Canada's senior basketball program. "They can't see the pictures, or they don't have the touch."

Thompson even kicks the ball to open shooters after offensive rebounds now instead of gathering it in a crouch, letting guards slap at it and getting stuffed at the rim. Thompson passed after 50 percent of his offensive boards, the fourth-highest such rate among the league's top 50 offensive rebounders, per SportVU data provided by STATS.

These are small, incremental changes. They did not make Thompson an appreciably different player or someone to count on for points. They would not have mattered much without LeBron.

With LeBron, incremental is enough. The Cavs don't need Thompson to post up or shoot jumpers. They don't even need him to make a functional play every time defenses abandon him. They just need him to do a little more than he could when he entered the league, without sacrificing any of his dirty-work relentlessness.

In 2015, the Cavs bet $82 million over five years that Thompson could hit the sweet spot. "That's why you are comfortable giving him the money," said David Griffin, Cleveland's GM. "Because you know he's the kind of person who's going to be worth it."

Team higher-ups were a little worried when Thompson began dating Khloe Kardashian in August, but now they are almost amused. When he comes to work, it's as if the Kardashian thing doesn't exist. Even Thompson's taste for fancy and sometimes garish clothes isn't new.

"He was always doing that," Lucas said. "Now it's Gucci, and back in college it was H&M or maybe Zara." (Some on the team jokingly worry that Thompson's pants are too tight and might split open at an inopportune time.)

Thompson has found full self-actualization as a player. He maximized his core skills and applied at least a little polish to his rough spots. He is essential.

"It's good for basketball to have guys buy into their role as fifth option, play it to a hilt, and get rewarded," said Mike Budenholzer, the Hawks' coach.

Thompson even likes the idea that his place at the bottom of Cleveland's scoring hierarchy makes every one of his contributions hurt more.

"People say I'm demoralizing, huh?" he asked. "Well, I'm honored. I like it. Everyone has to find their niche, right?"