Alabama's defense has plowed through Southeastern Conference competition, preying on suspect quarterback play and corralling talented running backs.
Now, the stakes get bigger and so do the challenges for the second-ranked Crimson Tide. The first order of business: Find a way to slow down quarterback Connor Cook and third-ranked Michigan State Dec. 31 in the playoff semifinals.
Sure, Alabama has faced an elite passer or two, including Mississippi State's Dak Prescott and explosive offenses such as Mississippi's attack. The Tide played against some of the best backs in the nation, shutting down LSU's Leonard Fournette and holding Georgia's Nick Chubb in check most of the way.
But there was also plenty of spotty quarterback play around the SEC this season. Not so for the teams in the playoffs, from No. 1 Clemson to the Spartans and No. 4 Oklahoma. All have proven quarterbacks and abundant playmakers.
''We're going to face better offenses,'' Tide defensive back Minkah Fitzpatrick said, ''so we're going to have to prove it over and over.''
There's little doubt that Alabama has one of the nation's best defenses. It's loaded with potential NFL first-round picks from linemen A'Shawn Robinson and Jarran Reed to linebacker Reggie Ragland. Young talent abounds, too, like freshman defensive back Minkah Fitzpatrick and defensive tackle Daron Payne.
The Tide leads the nation in run defense, ranks second in total yards allowed and third in scoring. Plus 14th in interceptions - including four returned for touchdowns - and third in sacks. In other words, a typical Alabama defense only with more depth and pass rushers.
But Alabama has faced struggling quarterbacks in its past two games, Florida's Treon Harris and Auburn's Jeremy Johnson. Cook is widely regarded as a potential first-round pick and leads the Big Ten in passing touchdowns.
If the Tide makes it to the championship game, the defense would face an array of offensive stars. It would be either Clemson's Heisman finalist Deshaun Watson, receiver Artavis Scott and running back Wayne Gallman or Oklahoma's Baker Mayfield, receiver Sterling Shepard and tailback Samaje Perine.
Defensive coordinator Kirby Smart, now Georgia's head coach, is staying with the team through the playoffs.
Florida and Auburn all but stopped handing off to the backs in the second half of their games. Michigan State coach Mark Dantonio said trying to stay true to the foundations that have made your team so successful is important.
Offensively, that's been mainly Cook (35 touchdowns) and receiver Aaron Burbridge (1,219 yards).
''I think everybody wants to bring who they are to the table,'' Dantonio said. ''It's why we got to where we're at. There's a combination of things, offensively, defensively, special teams that is the foundation for you. And you got to let your players play. And you've got to allow your players to do what they do best.''
Only five of the offenses Alabama has faced have ranked in the top 50 nationally in scoring offense, including 14th-rated Mississippi, the only team to beat the Tide. That game was hardly typical since Alabama committed five turnovers and gave up one long touchdown on a pass that deflected off a helmet.
Opposing offenses can pick their poison. They can test a secondary that seems to be the closest thing to a weak link, but safety Eddie Jackson & Co. have picked off 16 passes. Plus the Tide is averaging more than 3.5 sacks a game so quarterbacks must get the ball off quickly.
The defensive front is big, physical and as deep as any Nick Saban has had at Alabama. The Tide is allowing just 74 yards a game on the ground.
''We've got some of the best run-stoppers, best D-linemen in the country,'' linebacker Ryan Anderson said. ''That's the standard when you've got those guys, A'Shawn, JReed, Daron, (Darren) Lake.
''That's just the standard. They're a scary group.''