Jalen Hurts' emergence has helped Alabama prepare for Trevor Knight

In early January, Alabama cornerback Marlon Humphrey watched as a black-cloaked speck zigged and zagged in and around Alabama's defenders. With the early stages of a southern winter descending on Tuscaloosa, Humphrey and his teammates felt a burning frustration with every lunge and wrap-up that went unsuccessful due to the pint-sized presence new to Alabama's scout team.

Barely a freshman, Jalen Hurts was making his Tide debut as Clemson's Deshaun Watson, days before Alabama's national championship trip to Arizona. With his mobility and that irritating black, non-contact jersey on, Hurts introduced himself in dizzying fashion. Sure, that black force field made tackling obsolete, but with the moves he was making, Humphrey wasn't sure the big boys aching to bring him down stood much of a chance.

"I don't know if they could or not [tackle Hurts]," Humphrey recalled with a laugh. "It's still pretty hard to stop a guy like him."

Hurts' arrival signaled an overhaul of Alabama's offensive philosophy and also gave way to valuable teaching for a defense already classified as elite. But with the slippery, speedy Watson the final obstacle in front of Alabama's fourth national title under Nick Saban, Hurts became an experimental tool for this defense to use to get accustomed to facing a more fleet-footed foe behind center. Hurts wasn't just planting the seeds for an offensive revolution at Alabama, he was helping to change the direction of the Tide's defense.

"It does benefit you [on defense] to have a mobile guy like that," Saban said.

From enrolling early with the first task of mimicking a Heisman finalist to becoming the first true freshman to start at quarterback for Saban, Hurts has changed a lot about this Alabama football team, but his impact on his own defense is doing wonders for training this unit to shut down mobile quarterbacks.

At the end of the 2013 season, Alabama experienced a torturous loss to Trevor Knight and his Oklahoma Sooners in the Sugar Bowl. By the end of that disastrous night in Saban's old backyard, Alabama's defense had surrendered 516 yards and 38 points, with the mobile Knight accounting for 355 of those yards and four touchdowns. Saturday, Alabama gets a shot at revenge against the new-look, Aggie form of Knight with a faster, leaner, more-equipped and better-trained defense.

Back on that lonely night in New Orleans, Saban probably wasn't planning for this sort of moment, but the wheels of change were churning in his brain. Now, he has the type of quarterback who has frustrated and beat him in the past, and it could be the key to stopping Knight's -- and Texas A&M's -- Renaissance and keeping Alabama in the College Football Playoff driver's seat.

"Now, we see it all the time in practice before just seeing it only on Saturday," linebacker Shaun Dion Hamilton said of the defense adapting to Hurts' mobile play. "Practice makes perfect and that definitely carries over to the games on Saturday."

So far, it certainly has carried over. While the first trial run in Arizona ended with 478 total yards for Watson and 93 zone-read rushing yards for Clemson, Alabama walked away with a national championship. Mission accomplished yes, but improvement was still needed. This season, mobile quarterbacks Chad Kelly and Joshua Dobbs netted just 12 rushing yards, thanks in large part to six Alabama sacks and edge containment from its defensive ends. Alabama did surrender a season-high 522 yards to Ole Miss with Kelly's superb ability to extend plays and throw down field, but it held Tennessee to just 163 yards. Since the Clemson game, Alabama has allowed an average of 23.3 yards and 2.96 yards per carry on zone-read runs.

Shutting down Dobbs last week showed just how dominant this team can be with a little more patience and less mass to haul around, but Saturday's rematch with Knight should prove to be the biggest regular-season test. He has accounted for 2,002 offensive yards, including 502 rushing yards, and 18 touchdowns. Humphrey said Hurts' speed and wiggle are very similar to Knight's, but they also thrive when extending plays to keep passing plays alive. Saban also praised Knight's zone-read ability, which netted him 207 yards and four touchdowns in wins over ranked Arkansas and Tennessee.

The good news is that Hurts just had his best rushing performance of the season with 105 rushing yards, including a long of 45 yards, on zone-reads.

While players said that Alabama hasn't made wholesale schematic defensive changes, the abundance of spread opponents and more mobile quarterbacks has forced Saban's defenses to work more on containing, rather than overpowering. Players have shed pounds and increased their speed, but the ability to see a quarterback run and pass well consistently has helped to improve how defenders react to quarterbacks like Hurts and Knight, Humphrey said.

Their instincts have matured and their patience and conditioning have improved. Awareness for play-extending, improvising quarterbacks has grown after watching Hurts tear through the defense, starting with his scout-team days. Usually, scout-team quarterbacks have their scripted plays marked with when to run, but Hurts would routinely take off unsolicited. Hamilton and Humphrey said those moments were aggravating at first, completely disrupting what the defense had planned for, but the more it happened, the more the unit evolved and adjusted.

Alabama players think Hurts has provided a blueprint of sorts for Knight, making preparation that much easier. So much so that redshirt senior defensive lineman Dalvin Tomlinson, who had the displeasure of being on that 2013 team that lost to Knight, hasn't needed to watch a ton of Knight to know what to expect and how to stop it.

"Haven’t watched a lot of film on them, but from what I’ve seen its pretty similar," he said, "and I don’t think we should have too many problems with them.”