Clemson's Christian Wilkins will end his fourth and final season with the Tigers the same way he has ended each of the prior three: with a showdown against Alabama, and for the third time it comes in the College Football Playoff National Championship presented by AT&T (Monday, 8 p.m. ET, ESPN/ESPN App).

"I guess the only comparison is the Rocky movies," he said. "I know after three it's a trilogy. But what's four?"

It's a good question, though it's doubtful Nick Saban and Dabo Swinney have spent much time researching it. The on-field questions, however, deserve plenty of attention.

Sure, this is a matchup between two teams that know each other pretty well by now. Alabama came back to beat Clemson for a national championship to cap the 2015 season. Clemson returned the favor in 2016. Last season, the Tide topped the Tigers in the Allstate Sugar Bowl before upending Georgia for another title. And there are plenty of holdovers from those three, from Wilkins to the coaches to the undeniable heavyweight fight comparisons. But a lot has changed, too, and so we're digging into the details -- and hopefully avoiding too many Rocky allusions -- to find out who has the advantage in Part IV of college football's biggest rivalry.

Alabama X factor: Safety Deionte Thompson will have his hands full with all of Clemson's receivers, but Hunter Renfrow is another animal. Thompson can ask his predecessor, Minkah Fitzpatrick, about that. Fitzpatrick, a first-round pick and perhaps the best defensive back ever to come through Tuscaloosa, was torched by Renfrow in the team's three previous playoff matchups, where he caught a combined 22 passes for 211 yards and four touchdowns, including the winner in 2016. This game -- barring an 18th year of eligibility -- will be Renfrow's last chance to hurt the Tide, and it's up to Thompson to stop him on those pivotal third downs and red zone opportunities where he has been particularly effective.

play 1:00 Clemson's Ross erupts for 2 TDs & 100+ yards in 1st half Justyn Ross racks up 137 receiving yards and two touchdowns in the first half of the Cotton Bowl as Clemson leads Notre Dame.

Clemson's X factor: Renfrow seems the obvious answer here given his history against Alabama, but that success means he'll already have the Tide's attention. So instead, turn your attention to the defense, where Isaiah Simmons blossomed into the Tigers' leading tackler during the regular season and will be tasked with slowing down Alabama's slot receivers in the national championship game. Dorian O'Daniel was a key to Clemson's defense last season at the nickel/strongside linebacker spot, and Simmons has done admirably filling that hole in 2018, but this will be his biggest challenge of the season.

Alabama's breakout star: He gets overlooked, with quarterback Tua Tagovailoa and fellow wide receiver Jerry Jeudy dominating the postseason awards circuit, but Henry Ruggs III could be a real problem for a shaky Clemson secondary. The sophomore from Montgomery, Alabama, can take the top off a defense with his speed. This season, he has averaged 16.4 yards per catch. All told, he has 45 receptions for 738 yards and 11 touchdowns. If the focus shifts too much to the Biletnikoff Award winner, Jeudy, don't be surprised if Ruggs shows off his wheels and hands against the Tigers.

Clemson's breakout star: Justyn Ross was already a known commodity even before demolishing Notre Dame's secondary in the Goodyear Cotton Bowl Classic, but this game comes with even bigger stakes and an even bigger spotlight. Then there's the little matter of Ross being from Alabama and a top Tide target on the recruiting trail. The freshman has been a force in a backup role for Clemson all season, with 847 yards and eight touchdown grabs, but if he has a big game against his home-state team, you can be sure it'll put his name into headlines well outside of Clemson.

Matchups to watch

When Alabama has the ball: If you're looking for a weak link on the Clemson defense, it's the secondary. And rest assured that Tanner Muse & Co. are going to be tested by Alabama in ways that neither Notre Dame nor any other team the Tigers faced this season were capable of. We already mentioned Ruggs, and everyone already ought to know about Jeudy and his 1,176 yards and 13 touchdowns. But it's more than only those two. It's DeVonta Smith, last season's title-game hero who finally looked healthy again against Oklahoma when he caught six passes for 104 yards and a touchdown. It's also Jaylen Waddle, the lightning-fast freshman with 823 yards and seven touchdowns this season. And lest we forget, it's also Irv Smith Jr., an NFL-caliber tight end, who has seven touchdowns this season as well and could be a big-time red zone target Monday in Santa Clara, California.

When Clemson has the ball: The Tigers led the nation in rushing between the tackles, averaging nearly 7.4 yards per carry. For the season, Clemson gave up only four sacks from pass-rushers coming up the middle. Those are good signs but hardly enough to make anyone confident going against the likes of Quinnen Williams. Alabama's defensive front, led by Williams, is stout, and it has been largely successful containing Clemson's running game in the three most recent meetings. The difference this time is that Trevor Lawrence, while athletic, is not a run-first QB who can make up for a quickly collapsing pocket or a lackluster night from his tailbacks. That means there's plenty of pressure on the Tigers' Sean Pollard, Justin Falcinelli and John Simpson to hold their own in the trenches. Lawrence's quick release takes some of the pressure off, and Travis Etienne has vowed a better performance than last season's Sugar Bowl from the run game, but Williams is the biggest obstacle Clemson has faced all season at the point of attack.

Quinnen Williams has been a monster all season for the Crimson Tide. Can the Tigers slow him down? Brett Davis/USA TODAY Sports

Alabama's biggest lingering question: Will Christian Miller be available? And if he and his 8.5 sacks are able to take the field against Clemson, how close to 100 percent will he be? The senior is the defense's most consistent outside pass-rusher, and he didn't look so good the last time we saw him, limping off the field against Oklahoma because of a strained hamstring. With Terrell Lewis sidelined all season recovering from a torn ACL, there aren't many other proven options for Alabama to turn to if Miller can't be effective in this game. Maybe veteran Jamey Mosley steps up. Maybe, given the fact that Lawrence isn't as much of a threat to take off and run, Saban will consider using uber-athletic inside linebacker Dylan Moses in more pass-rushing situations. Or maybe it's one of the young guys like Eyabi Anoma or Cameron Latu who steps up and makes an impact. Whatever the case, someone needs to put pressure on Lawrence lest he be given the time he needs to carve up the secondary.

Clemson's biggest lingering question: How good is the secondary? After shutting down Notre Dame, defensive coordinator Brent Venables addressed the issue in his postgame speech. "The weakness of this defense?" he asked. "No, you're the heart and soul." That's a lot of belief in a unit that struggled badly against Texas A&M and South Carolina, and the challenge of Alabama's passing game dwarfs those matchups. Still, Muse, Simmons, Trayvon Mullen and others have heard enough of the criticism that they'll be playing with something to prove. A strong performance against Tagovailoa would certainly quiet the critics, and there's a good chance it would translate into a national championship for the Tigers.

Alabama player under the microscope: It's Jalen Hurts and his role in the trick plays that have come to define this series and how Hurts adds yet another dimension to that part of Saban's playbook. Because whenever the backup quarterback is on the field, it has to make defensive coordinators go crazy. If he's in for Tagovailoa at quarterback, you can't know if he's going to drop back and pass, or run the read-option where he's so effective. On the other hand, he has played some wide receiver, too, which presents its own set of problems. There, he can be motioned into the backfield in a jet-sweep action, or he can stay out wide and either run a traditional route downfield, or pull back, catch a backward pass and attempt a double-pass or run the ball. Throw in the fact that he could also set up in the shotgun alongside Tagovailoa and you've got even more possibilities for which to account.

Clemson player under the microscope: The dominance of the guys to his left and right take some of the pressure off senior defensive tackle Albert Huggins, but with Dexter Lawrence suspended following a failed drug test for a performance-enhancing substance, there's no doubt Huggins is shouldering a big load. Lawrence is a massive body and can control the line of scrimmage on his own. That's too much to ask of Huggins, but Clemson's D needs both to make Tagovailoa uncomfortable in the pocket and slow down Alabama's downhill rushing attack. Huggins won't have to do it alone, but he'll need to hold his own.

Tagovailoa's top concerns: We'll probably never know how healthy Tagovailoa is after undergoing surgery to repair a high ankle sprain a month ago. He said he thought he'd be 100 percent for the Orange Bowl, but then he got to Miami and put the number between 80 and 85. Then he looked great, throwing more touchdowns (four) than incompletions (three) before leaving the game with his ankle wrapped and in a walking boot. So who knows? The only thing we can say for sure is that his health is still worth monitoring. No one doubts that the Heisman Trophy runner-up and his 41 passing touchdowns will play Monday, but don't be surprised if Clemson's defense tries to rough him up early to see just how comfortable he is planting on his back foot and scrambling when the pocket collapses. As we saw against Georgia in the SEC championship game, a dinged-up Tagovailoa is a mortal Tagovailoa capable of making mistakes.

Will Alabama be able to rattle true freshman QB Trevor Lawrence? Kevin Jairaj/USA TODAY Sports

Lawrence's top concerns: It'd be easy enough to suggest inexperience is the biggest issue for Lawrence, who has yet to have a typical "freshman moment." But the guy has never seemed the least bit flustered this season, and there's no reason to think that'll change here. Instead, the bigger worry is how he'll be used in the run game. He ran more than he had all season against Notre Dame, and Clemson's biggest offensive success against Alabama in the past was spurred by Deshaun Watson's mobility. Will the Tigers risk hits on Lawrence if it means forcing the Tide D to consider his legs as a weapon, too? No one will confuse Lawrence with either of his predecessors -- Watson or Kelly Bryant -- to go against Alabama in the playoff, but he's athletic enough to do some damage, and if it can neutralize the pass rush just a bit, Lawrence's ability to read a defense and get the ball out of his hand quickly could translate into a big day with his arm.

Alabama wins if: Josh Jacobs, Damien Harris and Najee Harris combine for 200 or more rushing yards. Why? Because while Alabama is certainly capable of winning a shootout on the arm of Tagovailoa, it's probably not the safest route to a national championship. Just look at last week's Oklahoma game and how Jacobs & Co. were able to take the air out of the ball, limit the Sooners' possessions and preserve the victory. The final score -- Tide 45, Sooners 34 -- looked closer than the game actually was because the running game made the clock Oklahoma's enemy. Control the ball and it will allow Alabama to dictate tempo and give its defense time to rest against a talented Clemson offense with Lawrence, Ross and Etienne.

Clemson wins if: Tagovailoa spends some time on his back. No one will argue with Tagovailoa's talent. He's incredible. But he also has been awfully comfortable for much of the season, and that has made things easy for this Alabama offense. But if the Clemson secondary can hold up in coverage and force Tagovailoa to his second or third options, that should give the pass rush enough time to make him more than a bit uncomfortable. Do that enough times, and perhaps Tagovailoa gets impatient, perhaps he gets hit and loses the football, perhaps it's enough to rattle him just a tick. In a game this evenly matched, that might be all it takes.