Alabama leads the 10 best defenses in college football

With the college football season done with the exception of bowl games and the College Football Playoff, here's a look at the top ten defenses by total grade this season.

1. Alabama Crimson Tide

They have by far our highest cumulative defensive grade and it starts up front. Nose tackle Jarran Reed (+43.3) and defensive end A'Shawn Robinson (+25.8) are fantastic against the run, with Reed having the second highest grade of any player on the defensive interior. What makes this Alabama defense different from previous ones though is the pressure they can bring off the edge with Ryan Anderson (+30.3) and Tim Williams (+22.3) combining to rack up 17 sacks, nine hits and 47 hurries.

2. Michigan Wolverines

Talented up front and in the defensive backfield, the Wolverines have five defensive linemen with a grade of +20.0. All five of those players impressed both against the run and as pass rushers, with Chris Wormley (+35.8) the standout, racking up six sacks, five hits and 32 hurries. The defensive backfield boasts the best cornerback in the nation in Jourdan Lewis (+21.2) and one of the most versatile players in the country in safety and slot defender Jabrill Peppers (+16.1).

3. Ohio State Buckeyes

You can't talk about the Ohio State defense without starting with defensive end Joey Bosa (+66.6). Arguably the best defensive player in the nation, he has frustrated offensive with seven sacks, 21 hits and 41 hurries this year. They also boast the well standout defensive tackle Adolphus Washington (+47.1) and three starting linebackers who grade among the top 50 at the position this year in Darron Lee (+15.1), Raekwon McMillan (+18.2) and Joshua Perry (+22.8).

4. Boston College Eagles

No linebacker in the nation has a higher grade than Boston College's Steven Daniels (+47.6). The best run stuffing linebacker in the nation, he leads all linebackers with a run defense grade of +32.8 and is fifth at the position with 61 tackles resulting in a defensive stop. In the defensive backfield, safety Justin Simmons (+18.0) has been one of the best in the nation, both in coverage and against the run.

5. Wisconsin Badgers

They have talent at all three levels of the defense, but the stars of the Badgers defensive side of the ball are linebackers Joe Schobert (+44.4) and Vince Biegel (+43.4). Both have been tremendous pass rushers, combining for 18 sacks, 22 hits and 49 hurries.

6. Florida Gators

Defensive tackle Jonathan Bullard (+53.3) is one of the best in the nation against the run, but the highlight of this Florida defense comes on the back end. Vernon Hargreaves (+9.7) wasn't even the highest graded cornerback on the roster this year, with Jalen Tabor (+10.4) taking that honor. At safety, Marcus Maye (+22.0) impressed in coverage, but was great close to the line of scrimmage with a high grade against the run too.

7. Florida State Seminoles

Florida State have three players on their defensive line with a grade of +20.0 or better but like their in state rivals the Florida Gators, they are at their best in the defensive backfield. Cornerback Jalen Ramsey (+16.6) is one of the best corners in the nation, but the star is freshman Derwin James (+25.3). James impresses as a safety in coverage, in the slot, and in the box. Where he really impresses you though, is when he lines up as an edge defender. A defensive back with the skill set to beat offensive tackles, he's one to watch out for.

8. Boise State Broncos

They benefit from a softer schedule in the Mountain West, but the Boise State Broncos have a lot of good players on their defense. Up front edge rusher Kamalei Correa (+22.2) has racked up five sacks, 12 hits and 16 hurries in 2015. While at linebacker Tyler Gray (+27.3) has made his impact felt against the run, in coverage and as a pass rusher.

9. Ole Miss Rebels

Up front the best player for Ole Miss this year was defensive tackle Robert Nkemdiche (+35.1), but he wasn't the only one to impress, with D.J. Jones (+18.2) standing out against the run, and Marquis Haynes (+4.8) impressing as a pass rusher with 11 sacks, nine hits and 22 hurries.

10. Clemson Tigers

The number one ranked team in the college football playoff get a lot of credit for their offense, but their defense deserves a lot of credit too. Defensive end Shaq Lawson (+34.2) was their best pass rusher all year, and came up with a big play to force a fumble in the ACC Championship game. In the defensive backfield safety Jayron Kearse (+17.9) has been one of the best in the nation, grading well in coverage and against the run.