Jaalen Best sits with his chest out, wearing a beige bomber jacket over a white shirt with the top two buttons unbuttoned, carrying himself with the confidence of Muhammad Ali.
When asked how his day was going, Best replies, “I can’t complain, too good it’s a dag-gone shame.” His cadence and slang echo the legendary boxer — someone he has, in a way, become. And that confidence also seems rooted in the pride of landing his first lead role.
Best, 28, portrays Ali in the eight-episode Prime Video docuseries “The Greatest,” which premieres Wednesday.
Created by Ben Watkins, with Michael B. Jordan and Ali’s widow, Lonnie Ali, among its executive producers, “The Greatest” is the first authorized scripted series about his life, exploring his world beyond the ring and particularly his adoration for his family.
For Best, becoming Ali began during the audition process.
According to TeenVogue, Best was one of four actors Watkins had narrowed his focus on to cast. The test to decide who would get the role? A boxing workout.
Watkins gathered the four finalists, but he didn’t stay the entire workout to let them believe they weren’t always performing. Instead, a crew member posed as a front desk employee to observe the actors.
That night, Watkins had each actor study and memorize the third round of Ali’s gold medal bout at the 1960 Rome Olympics. Part of what set Best apart from other actors in the field was how much his frame resembled Ali’s.
Best worked to capture more than Ali’s resemblance. He had to immerse himself in Ali’s world to learn the boxer’s rhythm. Best said he trained with boxing coach Rob Sally for three hours a day, six days a week before securing the part. Outside the gym, Sally assigned footage of Ali boxing, shadowboxing and training, asking Best to return with notes on his movements.
“It would be ‘are his shoulders super relaxed’ or ‘the jab is really effortless or is fluid,’ or his uppercut when he turns — it’s like a pop with his shoulder or something of that magnitude,” Best told ESPN. “I would slow down footage of him moving around and bouncing and see the rhythm of his feet.”
Best brought an extensive athletic background to the work, including being a former walk-on basketball player at East Carolina. But translating those skills into Ali’s speed and precision required constant adjustments.
“It’s like ‘OK, he throws his jabs this way, he does that, he does this’ and my trainer would constantly tell me ‘too slow, not fast enough, not sharp enough,'” Best said. “‘You fully extend’ and it was just this constant thing, ‘get faster on your feet.'”
And along with studying how Ali carried himself in the ring, Best also researched and embraced the popular trends of that time period and implemented his findings as part of his training. During their sessions, Best said the soulful Motown sounds of James Brown and Sam Cooke mixed in with the likes of the current generation of artists such as Leon Bridges helped him establish a rhythm that made him comfortable in the ring.
“I’ve realized throughout the process, it was like poetry, it was like the blues or jazz music playing and you just dancing along,” Best said. “A bunch of that type of music that I could really just flow to was like truly floating and just being graceful on my feet.”
For Omari Hardwick, who plays Ali’s father, Cassius Clay Sr., the connection to the boxer was personal.
“We both obviously have a penchant for poetry, right? 
He was quite the poet,” Hardwick told ESPN.
Hardwick met Ali after connecting with his daughter Maryum at the 2015 NAACP Image Awards. She told him her father was a fan of his work in “Power,” leading to a visit with the family.
Hardwick later wrote about Ali in a poem featured on his album “never ghost: season 7.” He also came to view their meeting as a connection to the role he would eventually play.
“After I came, I conquered what I saw
with my God and a couple of his laws
you an imposter, I’m a problem with the trouble with in-laws…
the revolution my fable made sense it was televised on cable”
Omari Hardwick, “peOple’s cHamp”
“I got to always believe that it was Muhammad Ali asking me and not only asking, but going ‘You gonna play my daddy,’ I don’t think there’s a lot of asking there with him. I think his spirit told me, you’re gonna play my pops, figure it out,'” Hardwick told ESPN.
The role required Hardwick to portray a complicated father-son relationship. The series depicts Clay Sr.’s pride in his son alongside his jealousy and domestic violence against Ali’s mother, Odessa Grady Clay. It also explores his experience supporting a family under Jim Crow while his son became increasingly prominent.
“The one who works with his hands with gloves on is celebrated. The one who works with his hands with no gloves on, paint all over his hand, ain’t bothering nobody ain’t in the ring, ain’t fighting, just painting. It’s not necessarily celebrated,” Hardwick said.
Off-screen, Hardwick and Best developed a close bond while living near each other in Toronto. A father of two, Hardwick also wanted his children to build a connection with Best. Once he learned Best lived just around the corner, their bond grew stronger.
“I pick him up one day and I put him on the phone with [my son] Brave and I sat there and listen to them talk and I thought ‘Here’s my real life as a father matching me becoming a father,'” Hardwick told ESPN. “I don’t hear Omari no more. Jaalen calls me ‘Pops.'”
It made it easy for the two to have a father-son relationship on set.
Michael Ealy took a different approach to building his relationship with Best.
Cast as Malcolm X, Ealy asked Watkins to keep them apart until they filmed their first scene together. He wanted their first encounter to capture something of the anticipation the young Cassius Clay might have felt meeting Malcolm.
“It’s nothing personal, nothing like that. I just want the first time that Malcolm meets Cassius [Jr.] to be as authentic and organic and as real as possible,” Ealy explained to ESPN. “I don’t want to get to know him before this moment because I can imagine in my head what this was like for both of us.
“Young Cassius had the desire to meet Malcolm X and understand and talk to him about potentially joining the Nation [of Islam]. … And Jaalen did such a phenomenal job playing that. … I didn’t want to go in with any preconceived notion of who he was as a person, he was as an actor, I just wanted to see young Cassius Clay.”
Conversations with family members also informed the performances. Ealy spoke with Malcolm X’s daughter Attallah Shabazz about her father’s life as a husband and parent. Best and Hardwick turned to Lonnie Ali for insight into Muhammad’s life outside the ring.
For Best, connecting with Ali also meant understanding the ambition behind his most famous declaration.
“‘I am the greatest’ and having to prove yourself, prove a point to just be someone that wants to mean something to the world in a much bigger place than sport,” Best said.
