CFB Playoff Rankings: What it will take for top teams to stay there

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The first College Football Playoff ranking was released on Tuesday night with some minor surprises. The top four teams were Alabama at No. 1 followed by Clemson, LSU and Notre Dame, but all of these teams still have work to do before they are locked into the College Football Playoff.

The top four teams in the final poll released Dec. 2 advance to the national semifinals Dec. 29. The semifinal winners will meet for the national title Jan. 7 in Santa Clara, Calif.

Here are the reasons why each of these four teams in this season's first CFB Playoff poll will make it all the way to the playoff, why they won't, and the key player who could carry them there.

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Why they will make it: Let's be honest, this is an absolute no-brainer. Alabama looks like far and away the best team in college football with an offense that won't quit and a suffocating defense. Nick Saban has successfully navigated the "Tua Tagovailoa or Jalen Hurts" dilemma at quarterback and his defense again ranks near the top of many statistical categories. Offensive coordinator Mike Locksley is guiding the most explosive Crimson Tide offense ever and has it ranked No. 1 in total offense and scoring offense. Tagovailoa has become the most efficient quarterback in the country and favorite to win the Heisman Trophy.

If Alabama can get by LSU on Saturday, the Tide should walk into the SEC Championship game with all the momentum they need to carry them into the College Football Playoff.

Why they won't make it: Alabama's toughest games are ahead. It starts Saturday at No. 4 LSU and there are still potentially pesky games remaining against Mississippi State and Auburn and, if the Crimson Tide wins out, the SEC East champion. A loss at any point in these final games could derail what has been a perfect season up to this point.

The Crimson Tide have remained relatively healthy so far this year but one of the biggest questions has been about the level of depth on defense, specifically in the secondary. An injury or two could expose some untested youth and make Saban's defense a bit more susceptible in the passing game.

The key player to take them there: Tagovailoa. Simply put, teams haven’t figured out how to stop him and as long as he performs well the Crimson Tide should be hoisting the national championship trophy again.

Why they will make it: Sporting one of the best defensive lines in recent memory, Clemson is a force and getting better on both sides of the ball. On the offensive side, freshman quarterback Trevor Lawrence has settled into his starting role nicely and he has made this offense much more explosive.

The Tigers have a relatively easy path to run the table the rest of the way in the ACC. Clemson, over the last few years, has become a proven product and many people believe that the Tigers are playing at full potential and are the only team that can challenge the Crimson Tide.

Why they won't make it: Two interesting games could trip up Clemson – an interesting road game at Boston College and the annual rivalry game against South Carolina. A loss would all but eliminate Clemson from College Football Playoff contention and would really damage the ACC's already shaky credibility this season. NC State's loss at Syracuse doesn't help Clemson's resume either.

A lack of speed at linebacker and sometimes vulnerable safeties give explosive offenses a window for success against the Clemson defense, and the interior of its offensive line isn't close to solid. Those weaknesses give opposing teams a glimmer of hope against this very talented Clemson team.

The key player to take them there: Lawrence. His performance is the ceiling for how good Clemson can be.

Why they will make it: The Tigers will be in the College Football Playoff if Joe Burrow continues to effectively manage this offense. LSU has a great running game and offensive coordinator Steve Ensminger is rotating in a lot of players to help create mismatches and give the Tigers the edge wherever possible.

With the resume they’ve already put together, LSU deserves to be in this first top four and if it wins out against Alabama, Texas A&M on the road and in the SEC title game, LSU will be the favorite to win the national championship.

Why they won't make it: LSU’s College Football Playoff hopes boil down to Saturday's game against Alabama. The Tigers need to win because a two-loss team won’t be in the final four. Burrow has been good this year but he hasn’t been asked to make many huge plays or exceptional throws. He will have to step his game up and look for his talented receivers to do the same.

On the other side of the ball, LSU's pass rush has not been as consistent as we've seen in the past. Disrupting Alabama quarterback Tua Tagovailoa's timing is a must for the Tigers. Ed Orgeron will have to find ways to make sure Alabama can't exploit the absence of linebacker Devin White. The star linebacker will miss the first half of this weekend's game because of a targeting penalty two weeks ago against Mississippi State.

If LSU can get by Alabama, Texas A&M can be dangerous and of course the SEC title game will be a tough one.

The key player to take them there: Burrow. Managing games are one thing but Burrow has to be up to the challenge against Alabama.

Why they will make it: Notre Dame has passed every test it has been given so far this season and many of the wins weren’t as close as the scores have indicated. Switching from Brandon Wimbush to Ian Book at quarterback and getting running back Dexter Williams back four games into the season has helped the Fighting Irish put their offense in gear.

This isn’t your parents’ big, slow Fighting Irish defense. For that matter, it's not the Notre Dame defense from the 2013 national championship game against Alabama, either. The athleticism of this front seven is off the charts and it can absolutely dominate a game. The secondary is opportunistic and does a great job playing off the pressure the front seven gets on the opposing quarterbacks.

Why they won't make it: Looking at Notre Dame’s schedule, it feels pretty weak right now. The only team the Irish beat that is currently ranked is Michigan and it’s pretty clear that this Michigan team is very different than the one Notre Dame beat in the season opener. If the Fighting Irish slip up in November, something they’ve done in the past, they won’t make the College Football Playoff. Their resume won't be good enough to get in with one loss. They play on the road at a tough Northwestern team this weekend before consecutive home games against Florida State and a ranked Syracuse squad that can score with anybody. And, of course, Notre Dame ends the regular season on the road at USC. If any of these teams can establish the run and take away the short throws that Book loves, it could spell trouble for Notre Dame.

The key player to take them there: Defensive lineman Jerry Tillery. Notre Dame’s best defensive lineman is so disruptive when he plays well and offenses need to pay extra attention to him, freeing up his teammates to make a ton of plays.