FORT LAUDERDALE, Fla. — Alabama ranks first nationally in total defense, and it’s a large reason the Crimson Tide will enter Monday night’s BCS National Championship Game as a 10-point favorite.

But who deserves the credit? Is this Alabama head coach Nick Saban’s defense, while Kirby Smart is little more than a glorified position coach who has the coordinator title and draws a nice salary? Or has Saban simply laid down the guidelines for Smart, who has taken them and imagined something that’s a little different and just as productive as what his boss might produce?

The truth is somewhere in between.

Certainly, the defensive-minded Saban has coached since 1973, two years before Smart was born. Saban coordinated his first defense in 1983 when Smart was 7. In addition, Smart had only one year of experience as a defensive coordinator (2001 at Division II Valdosta State) when Saban hired him in 2008.

It didn’t seem like such a big deal when Saban named Smart the defensive coordinator. After all, we all just knew for an absolutely certainty Smart wouldn’t be allowed to run the actual defense, wink, wink, nudge, nudge. Sarcasm intended.

But if football is a class and Saban is the teacher, then Smart is the A-plus student. He willingly says Saban has made him the coach he is today. And that’s an awfully good one.

Part of managing a team includes replacing yourself on your coaching staff, and Saban, the ace defensive coordinator, has replaced himself with ... an ace defensive coordinator.

Smart, 37, really does run Alabama’s defense. Of course, Saban has the final say over Smart’s plans. But has taken the base of knowledge Saban has given him and created something that can win big.

Because of that, Smart has earned such trust from Saban he gets more freedom to do what he wants than offensive coordinator Doug Nussmeier. To be fair, Nussmeier has coordinated Alabama’s offense for only 13 games. Meanwhile, Smart has had five years to prove over and over he deserves the long leash Saban gives him.

“We speak the same language and have been on the same page for a long time, so I have total faith, trust and confidence in what he’s doing during the game in terms of calling the game as well as making adjustments,” Saban said recently.

It’s easy to get confused about who actually runs the defense because Saban almost never allows his staff members to speak to reporters. Saban always serves as the spokesman for the defense, leading reasonable people to believe he created it and runs it.

The no-interview policy is nothing against Smart. Instead, Saban has told reporters he wants one voice — and one voice only — to represent his program.

But when Smart gets a rare chance in front of reporters, as he did Thursday in a 40-minute session, he looks a little less like a Barney Rubble look-a-like and a little more like a potential head coach.

The players say Smart has shown he can be just as tough as Saban. When Smart first joined the Alabama staff, he handled the safeties. Robert Lester, now a senior and a three-year starter, was a freshman destined to be redshirted that season.

Lester said he struggled so badly to understand one day, Smart told him to get off the field.

But the players say Smart also teaches and analyzes exceptionally well, too. Lester said Smart telling him to get off the field helped focus his attention. Smart eventually got through to him, and you see the result today.

Linebacker Nico Johnson said when the defensive players leave the field, Smart is there, already giving the answers to any questions they possibly could have.

Johnson said it’s why he is called “Coach Smart.” He’s the coach of the defense, and he’s, well, smart.

When Smart leaves for a head coaching job, it won’t be gloom and doom for Alabama defense. Saban will find another bright young coach to handle.

But at that time, we’ll see if Smart has absorbed Saban’s biggest lesson — don’t forget to replace yourself. When Smart becomes the head coach, he’ll need his own ace coordinator to imagine another great defense.

Contact Decatur Daily Sports Editor Mark Edwards at mark.edwards@decaturdaily.com. Follow on Twitter at @DailyEdwards.