Christina Hendricks was cast alongside Naomi Watts and Liev Schreiber back in 2011 when the project was announced. Hendricks dropped out while the film was stuck in development and eventually Elisabeth Moss replaced her.

James Brown sang in the ring before the Ali-Wepner fight and did a pre-fight performance on screen in Rocky IV.

Liev Schreiber & Naomi Watts were a couple in real life, until they called off their engagement in 2016.

Chuck Wepner was the real-life inspiration for Sylvester Stallone's character Rocky Balboa.

Was originally called "The Bleeder", but changed to "Chuck" due to viewers thinking it was a horror film, as well as other movies with the same name according to Chuck Wepner. In several European countries, the movie was still released as "The Bleeder", though.

Liev Schreiber and Pooch Hall who play Chuck Wepner and Muhammad Ali in the film, have also starred together as half brothers in the Showtime original series Ray Donovan.

Chuck tells Linda the bartender that she takes a good license photo, but New Jersey didn't start putting photos on licenses until the late 1990s.

Chuck states, "What Bayonne makes, the world takes". This is in reference to the quote on the Lower Trenton Bridge in Trenton, NJ, "What Trenton makes, the world takes". This refers to the manufacturing industries that dominated Trenton in the early 1900's.

Chuck gets into a phone booth on the street next to a No Turn on Red sign. Being able to turn right on red wasn't law in NJ until 1979.

Liev Schreiber, unlike his character Chuck Wepner, does have a role in the "Rocky" franchise. He assumes his real-life role as the narrator of HBO Sports Documentaries in the film "Creed", a spin-off of Rocky's saga.

Liev Schreiber has acted in two different boxing movies set in New Jersey, this movie and The Hurricane (1999)

Chuck watches TV that's marked AOC. The Wepner-Ali fight was in 1975. Taiwan's AOC did not start exporting until 1979, and not to the US until much later.

Chuck (Liev Schreiber) mentions that even though Rocky (1976) was clearly inspired by his life and career, he never saw a penny for it. What the film doesn't show is that after his failed audition for Rocky II (1979), Sylvester Stallone promised the real Wepner a part in one of his future movies, but this never materialized, not even when Stallone was filming Cop Land (1997) close to Wepner's home. Wepner finally sued Stallone in 2003 for the use of his life story, which Stallone denied. The case was finally settled for an undisclosed sum.

At the end, Chuck refuses to speak to Sylvester Stallone (Morgan Spector) who is making Lock Up (1989) inside his prison. In reality, Chuck Wepner did have a talk with the real Sylvester Stallone, who acknowledged him as 'the real Rocky' to the other inmates.

The real Chuck Wepner was indeed tested for the part of "Chink Weber" in Rocky II (1979), but when he failed his audition, the character was dropped from the movie. The name was used for the character of Sonny Landham in Lock Up (1989) instead, the movie that Stallone (Morgan Spector) can be seen making inside Wepner's prison at the end.

At the first part of the movie you'll see a hand painted sign containing the phrase "old school". I always thought the phrase "old school" was a rather modern, hipster invention. It turns out the term itself is rather old-school, with Webster reporting the first recorded use in 1803.