Boston Celtics president Danny Ainge made one of the great trades in NBA history in 2017, when he sent the No. 1 overall pick in the draft to the Philadelphia 76ers in exchange for the No. 3 pick and a protected future first-rounder.

Ainge preferred Duke's Jayson Tatum over presumptive top pick Markelle Fultz out of Washington (the Los Angeles Lakers were set on UCLA's Lonzo Ball at No. 2). Three years later, Ainge's intuition has proven correct.

Fultz's struggles in Philly were well-documented, and the Sixers ended up trading their top pick to the Orlando Magic in Feb. 2019, where he has found a nice role.

Tatum, on the other hand, was a polished prospect who was posterizing LeBron James as a member of the Celtics in the Eastern Conference Finals as a rookie and has since ascended into near-superstardom.

Ainge made another strong pick the year before, in 2016, when he selected Jaylen Brown out of Cal at No. 3. Together, Brown and Tatum have blossomed into the best (and most versatile) two-way wing duo in the East, and have provided the Celtics with an enviable foundation for years to come (Kemba Walker helps, too).

At 23, Brown is not only an All-Star-caliber player, but also one of the most profound people in sports. Turns out, that profundity may have influenced Ainge ahead of the 2017 draft.

Brown was in Europe in the hours before the draft when he got a call at 4 a.m. from Ainge. Brown thought he had been traded, but the Celtics president was calling for a second opinion regarding Tatum and Josh Jackson, who Ainge was considering, too.

Despite the overlap in Brown and Tatum's style, Brown advocated for the former Duke Blue Devil:

“I told him, ‘JT is your guy,’” Brown told Chris Mannix of Sports Illustrated . “He probably called a lot of people, but he called me as well. I don't know if that gave him any confirmation, but I told him what I thought. I was like, ‘Let’s go.’”

Tatum and Brown were friendly from various camps and basketball events, but the fit on the Celtics was not a guarantee. Tatum said they knew building chemistry was going to be paramount:

“It wasn’t like meeting a stranger,” Tatum said. “We kind of understood early on that we were going to be relied upon heavily, even as young guys…We pushed each other.”

While the two aren't exactly the same people off the court, the mutual respect is apparent:

“I've spent a lot of time with JT in the last two years,” Brown said. “I’ve gotten to know him very, very well. We have different interests. We respect our different interests…We respect each other's differences. He’s still cool to this day.”

Tatum and Brown will aim to give the Celtics a 2-0 series lead over the Toronto Raptors in the Eastern Conference Semifinals on Tuesday.