It was an off day in December, and Richardson was finishing up his workout with 100 three-point attempts. He made 64 of those shots and started gathering his things to go. Then, Heat coach Erik Spoelstra walked in.
"J-Rich, how many did you make?" the skipper asked.
"Uh, 64," Richardson said.
"No, no. We're shooting again," Spoelstra said. "You've got to make 70."
After another 100 shots, Richardson had 65 makes. The next time it was 69.
"Are we going to get this, or are you going to make me waste my whole day in here?" Spoelstra asked.
"Jesus, you're right," Richardson said. "I gotta get it together."
Now shirtless, frustrated and sweaty from the shooting and sprints he ran in between, the rookie could feel his fingers wrapping around his ticket out of the gym. He was 69-of-99, one shot away from getting on with his day or starting all over. He aimed and fired.
"I thought it was short," Richardson said.
"I held my follow-through even after it hit the ground through the net," he said. "I was like, 'Thank God, it's over. I finally made 70.'"
As relieving as that was for Richardson, it was perhaps more validating for the Heat. It was evidence that they'd guessed right on a prospect's growth—again.
Last season, they took a deeply discounted flier on former second-round pick Hassan Whiteside and promptly witnessed his remarkable rise to stardom. They also grabbed undrafted guard Tyler Johnson, ran him through their NBA D-League program and watched him emerge as an energetic, three-point-sniping reserve.
Miami's gamble on Richardson was twofold. For starters, it wagered that a 31.8 percent three-point shooter during four years of collegiate hoops could have a promising future as an NBA sniper.
"We saw a shot that was mechanically pretty solid," Spoelstra explained. "He didn't shoot a real high three-point percentage in our shooting drills, but you saw it was mechanically something you could work with. I remember in a coaching meeting we said, 'J-Rich will improve dramatically with our program just with a ton of reps.'"
Therein lies the second part of the Heat's bet. Even if they could see Richardson's potential, they still needed him to invest the sweat equity required to realize it. They planned on working him hard, but there's never a guarantee a prospect will respond to those demands the right way.
"Our program's not for everybody," Spoelstra said. "It's just not. You have to be the right individual and embrace the work, embrace the sweat, embrace the every-single-day grind. Some people get chewed up by it."
Richardson isn't one of those people.
He's been a gym rat since the Heat selected him 40th overall, 16 spots behind where they had him graded. Perimeter shooting is one of his main focuses; he says he takes at least 200 triples a day. It has been since the start of the year, when he struggled to see major minutes unless he was suiting up for the Sioux Falls Skyforce, Miami's D-League affiliate.
"[Heat assistant coach David] Fizdale always told me, 'Just stay ready,'" Richardson said. "He said somehow, someway, they were going to need me for a playoff push. I stayed ready. I stayed in the gym."
He entered the All-Star break averaging just 11.5 minutes over 23 games. Trades (Mario Chalmers) and injuries (Johnson and Beno Udrih) thinned the backcourt barriers in front of Richardson. He's been a lineup fixture ever since, logging 26.5 minutes a night in all of Miami's 17 post-intermission games.
"I remember when Beno went down, I texted him and told him we need him to step up," fellow freshman Justise Winslow said. "Ever since then, he has been."
That's the least dramatic way to put it.
Oh, and those countless shooting sessions have paid off in the form of a league-best 60.4 percent three-point conversion rate (minimum 20 attempts).
"I feel like the goal is really big right now," he said. "I feel like if I shoot...it's most likely gonna go in."
His long-distance development is the most striking part of this story, given the amount of work it required. But that's not the only thing Richardson has provided. At 6'6" with a 6'10" wingspan, Richardson combines length, athleticism, quickness and effort to form a disruptive defensive package.
His defense is tenacious—or "scrappy," as Stephen Curry called it after being harassed by Richardson during Miami's late-February loss to the defending champs.
While he has room to grow as a playmaker, he has helped fill Miami's void at backup point guard. He hits the open court like he's been shot out of a cannon, and that aggressiveness fits perfectly with the Heat's new uptempo scheme.
"He is shooting really well from three, attacking the rim, defending," Goran Dragic said. "He is an all-around player."
Richardson said he doesn't know if his name shows up on opposing scouting reports yet, but that time is coming. Not that he'll mind the extra attention. If teams want to chase him off the arc, he can pull something else from his bag of tricks.
"I'll just have to go past them," he said. "It's all good. One or the other, pick your poison."
Richardson's confidence, like his production, is at an all-time high. That's not a coincidence.
What's happened the last month is, by his own words, "a product of hard work." It's helped having an opportunity, holding a stable rotation spot and stringing together good performances, but the trust in his abilities stems mostly from his behind-the-scenes effort.
"Every level, I've always had to work for everything," he said. "I never really came into a program and had it like, 'OK, you're starting,' or, 'OK, you're our best player.' It's never been like that, so it's just kind of ingrained in my brain to just work every day."
That determination not only led Richardson to the NBA; it also drew the Heat to him. While this franchise has seemingly made a habit of uncovering incredibly fortunate finds, this isn't blind luck.
The Heat know what they'll require of their youngsters, so they target guys they think will respond the right way. By the time their hidden gems start to surface, they've already seen the foundation laid to support these climbs.
"You have to have the right kind of player," Spoelstra said. "A lot of players just really aren't willing to put in that kind of work."