Being a great head coach isn't just about X's and O's and having a perfect scheme — though that certainly helps.

Every great head coach — in any sport — has first and foremost been an elite leader.

Ultimately, that's what determines success — especially in college football.

If a head coach can't get an entire program — players, assistant coaches, support staff, trainers, etc — to follow him then he's going to fail. It doesn't matter how good of a scheme the coach has.

Fortunately for the Tennessee Vols, head football coach Josh Heupel has both a great scheme and great leadership abilities.

Heupel has proved throughout his career that he is an elite leader.

And here are three specific ways he's proved it.

1. Leading Oklahoma to a national championship

When Heupel landed at Oklahoma in 1999, he was an unknown. He was a player that wasn't highly recruited coming out of high school. He had spent time at Weber State and Snow College. Heupel wasn't supposed to lead a program like Oklahoma.

Heupel was Bob Stoops' first quarterback at Oklahoma after being discovered by Mike Leach (then OU's offensive coordinator). In 1999, Heupel helped the program to its first winning season since 1993. In 2000, Heupel led the Sooners to a 13-0 record and a win in the BCS national championship game against Florida State (Stoops' only national championship). A player like Heupel doesn't lead a program like Oklahoma to that type of success without being an elite leader. Stoops never had another undefeated season at Oklahoma after 2000. Heupel deserves more credit for that championship than Stoops.

2. Taking over at UCF and leading the team to a 12-1 record

A lot of folks are dismissive of Heupel's 12-1 record with UCF in 2018. That's because the Knights went 13-0 under Scott Frost in 2017. The thought is that Heupel took over an easy situation and just coached the team while on cruise control in 2018.

But that's not necessarily the case.

In fact, I think what Heupel accomplished in 2018 was one of the most impressive coaching jobs in his career.

Taking over a team with high expectations isn't easy. Heupel didn't walk into UCF and do things the same way Frost was doing things. Heupel changed the offense up (they went faster under Heupel with a different approach). He did things his way.

The players bought in and the program nearly went undefeated again. Unfortunately for UCF, they ran into a transcendent quarterback in LSU's Joe Burrow in the Fiesta Bowl. That game was the game where Burrow put himself on the national radar.

3. Turning Tennessee around

Heupel has taken over two very different situations in his career (at UCF and Tennessee). And he's been very successful at both.

The approach by Heupel at UCF and Tennessee had to be different. Taking over at UCF was a much different situation than taking over at Tennessee.

UT was in a disastrous spot. An NCAA investigation, players leaving left and right, coming off a 3-7 season. It was a less-than-ideal scenario for a new head coach.

Heupel surveyed the situation, understood what Tennessee needed, and went to work. If he would've went into the UT job approaching it the same way as the UCF job, he would've failed. Instead, the Vols went 7-6 when most analysts were expecting 4-8 or 5-7.

That's what makes Heupel such a great leader. He understands he has to adapt. He's willing to adjust his process based on the situation.

Coaches that fail usually won't change their approach. Coaches that succeed are always willing to adapt.

The Vols are fortunate to have a coach like Heupel who has proved he can win in any situation.

Featured image via Calvin Mattheis/News Sentinel / USA TODAY NETWORK