College Football Playoffs 2015: Most Important Players in National Semifinals

You can argue as much as you want about the College Football Playoff, but it is impossible to deny the committee gave fans two great games with elite talent on all four squads.

Between All-Conference players, All-Americans and Heisman winners, there are a number of big-time stars who could impact each game in the national semifinals. The question is, which competitors will have the biggest roles in deciding the outcome?

A mistake or great performance by anyone could help affect which squads will play for a national championship, but these players are likely to have the biggest impact on the upcoming games.

10. Cardale Jones, QB, Ohio State

After losing Braxton Miller and then J.T. Barrett to injury, many teams would've given up. However, Ohio State kept going, as Cardale Jones carried the torch for the offense in a 59-0 win over Wisconsin in the Big Ten title game.

While the Sugar Bowl represents just his second career start, this could actually be beneficial against Alabama. As Crimson Tide head coach Nick Saban explained to ESPN's Adam Rittenberg, the lack of film on Jones makes him difficult to game-plan against:

Still, Jones wasn't asked to do too much against Wisconsin. Against Alabama, the sophomore will have more pressure on him with the fate of the Buckeyes in his hands.

9. Troy Hill, CB, Oregon

The Oregon defense took a major hit when All-American cornerback Ifo Ekpre-Olomu was sidelined for the postseason after injuring his knee in practice. As a result, the rest of the secondary will have to seriously step up against Florida State.

Fortunately, the Ducks have someone ready to be the No. 1 option at cornerback in senior Troy Hill. Opposing quarterbacks have looked in his direction for much of the season to avoid Ekpre-Olomu, but Hill came through with a team-leading 17 passes defended.

He and safety Erick Dargan will make sure the Oregon defense will remain as solid as it has been lately.

8. Blake Sims, QB, Alabama

It didn't seem like Blake Sims would win the starting quarterback job coming into the season, but it's a good thing he did because his play is a major reason Alabama is currently the No. 1 team in the nation.

The senior put up big numbers this year, but more importantly, he changed the offense with his ability to make accurate passes as well as extend plays with his legs. He has given opponents yet another dimension to defend on a field with a lot of skill players.

As long as he can keep up his recent level of play and avoid mistakes, Alabama should be just fine.

7. Jalen Ramsey, S, Florida State

It's hard to find a more versatile defender than Jalen Ramsey. The safety can line up just off the defensive line or deep into coverage and have success from any spot.

Even Oregon Ducks quarterback Marcus Mariota is impressed with what he has seen from the sophomore on film:

Ramsey has filled up the stat sheet this year with 9.5 tackles for loss, three sacks, two interceptions and 13 passes defended. He always seems to be around the ball, and his speed and instincts will be a major part of the Seminoles' ability to slow down Oregon's red-hot offense. 

6. Amari Cooper, WR, Alabama

The Heisman Trophy finalist was outstanding this season, leading all FBS players with 115 catches to go with 1,656 receiving yards and 14 touchdowns. He can burn a defender and get open down the field or simply take a screen pass and break a few tackles to go the distance.

On the downside, the Tide have become incredibly reliant on Cooper. The receiver has about 43 percent of the team's receptions this season, including three times more than DeAndrew White, who's second on the team.

He has turned himself into an excellent player, but he better match his recent play or else Alabama will be in trouble. 

5. Joey Bosa, DL, Ohio State

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One of the most effective defensive players in the nation, Joey Bosa has NFL teams disappointed that he is only a sophomore. It will take at least another year until he can make an impact at the next level.

Until then, Bosa will have to satisfy as one of the top defensive linemen in the nation. He finished the regular season with 50 tackles, including 20 for loss, and 13.5 sacks. He does an excellent job of getting into the backfield and blowing up both passes and run plays.

As good as Alabama has become offensively, Bosa has a chance to single-handedly slow down the Tide if he plays to his ability. 

4. Landon Collins, S, Alabama

Most teams don't want to see the safety finish the year with too many tackles. This usually means the stops are coming down the field and the defensive is struggling.

That is not the case with Alabama and Landon Collins, a hard-hitting safety who is excellent against the run and always finds a way to make tackles right at the line. He currently has 91 tackles and has also done a great job in coverage.

Ohio State usually finds ways to get a few long plays every game, but Collins will be the person trying to prevent this from happening. 

3. Ezekiel Elliott, RB, Ohio State

Although Cardale Jones will be important, Ohio State's offense goes through Ezekiel Elliott. In his first year as a featured back, the sophomore has amassed 1,402 rushing yards and 12 touchdowns to help the team move the football regardless of who is under center.

The Big Ten championship was by far Elliott's best game of the year, as he totaled 220 yards and two touchdowns on 22 carries.

With plenty of questions in the passing game, the Buckeyes will lean heavily on the running back and hope he can once again carry the squad to victory.

2. Jameis Winston, QB, Florida State

Jameis Winston was considered by far the best player in the nation a year ago, but the quarterback has struggled for much of the 2014 season. His incredible efficiency that he showed en route to winning the Heisman Trophy was gone this year, and he ended up throwing a putrid 17 interceptions 

The good news, though, is he is coming off one of the best performances of the season against Georgia Tech in the ACC Championship Game. ESPN's Andrea Adelson and Mike Greenberg agreed on this fact in the most recent win:

After throwing four interceptions in a win the week before, Winston kept his mistakes to a minimum. If he can do this again, the Seminoles will have a serious chance to upset Oregon and advance to the title game.

1. Marcus Mariota, QB, Oregon

The Heisman Trophy winner is not only the best player in the nation—he is the most important person on any team contending for a national championship.

Oregon dealt with injuries to the offensive line and shifts in roles for playmakers, but Marcus Mariota heads into the Rose Bowl with 38 passing touchdowns, 14 rushing touchdowns and just two interceptions.

While you can call him a system quarterback, no one else would be as productive in this offense. More importantly, it's hard to imagine the Ducks having any success if Mariota wasn't at his best. This means he better show up for the squad to advance to the national title game.

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