If you think you’re going to get a candid look at the personal lives of Nick Saban and Bill Belichick in the new HBO documentary that premieres tonight, forget it.

Even when the two coaching icons are left alone to visit and catch up with each other the topic of conversation is football.

In the opening scene in the documentary from HBO Sports and NFL Films, ‘Belichick & Saban: The Art of Coaching,’ the camera crew is in Saban’s office. Belichick asks the camera crew to leave so the two can just sit down and have a conversation.

One camera remained turned on and captured the sit-down. The chat isn’t about family, politics or even personal.

It’s all about football.

It’s a powerful moment that gives viewers insight on how both of these coaches are the best at what they do. They have met once a year for the past 40 years to discuss the game and share ideas.

The documentary airs 8 p.m. on HBO.

Football is what drives these two men, and the movie tries to capture the similarities between the two, who share similar childhood backgrounds, heritage and coaching philosophy.

“Because of social media they are getting a lot of their positive self-gratification by the communication they have without looking somebody in the eye and without developing a relationship with them,” said Saban during an exchange with Belichick in the film. “That’s a critical part they all need to have to develop and you need to have to have a team.”

Responded Belichick, “No question. Who cares how many likes you get from 2,000 people you don’t even know. The 53 guys in the locker room, those are the 53 are the guys that matter. I don’t know if that always gets through or not, but we keep pounding away and keep trying.”

Belichick and Saban met in 1982 in Annapolis, Maryland, home of the United States Naval Academy, where Saban served as an assistant coach alongside Bill’s father, Steve Belichick. Their first encounter sparked one of football’s most powerful friendships.In 1991, Belichick was named head coach of the Cleveland Browns, and shortly thereafter he hired Saban to command his defense. Under their tutelage, the Browns produced one of the NFL’s most formidable units. Their early success foreshadowed more than two decades of dominance.Since then, Belichick has led the New England Patriots to six Super Bowl victories, while Saban has amassed six national championships.