Can Ohio State's Defense Fuel a Run to the College Football Playoff?

When the College Football Playoff selection committee released its first Top 25 rankings on Tuesday night, Ohio State (6-1) was buried at No. 16—placed behind 13 other one-loss teams.

The Buckeyes are facing a major uphill battle with just five games remaining in the regular season, needing to rise 12 spots in order to have a shot at this year's national title. 

A vastly improved and surging defense could push the Buckeyes up that hill and back into the playoff conversation.

Ohio State has been known for its offense since Urban Meyer took over three years ago, but in 2013, a leaky defense that surrendered an average of 38.3 points and 539 total yards to its final three opponents—Michigan, Michigan State and Clemson—cost the Buckeyes a chance to play for the national championship.

That prompted the hiring of Chris Ash as co-defensive coordinator and the complete overhaul of Luke Fickell's unit.

Meyer wanted a scheme that featured his defenders attacking the ball as opposed to the soft zones that opponents could pick apart.

That, in essence, is what drove Ash to join Meyer's staff.

“[Meyer] said he wanted a defense that challenges the offense, that’s aggressive, that will attack, not worry about the ‘what ifs,’ create confusion,” Ash told Stewart Mandel of Fox Sports. “Those are things I believe in to be successful. When he started talking my language, I started listening.”

Jay LaPrete/Associated Press

Early returns from Ash's overhaul have been positive, as opposing teams are having a much harder time moving the ball against this year's Buckeyes.

Through seven games, Ohio State ranks 11th in total defense, 17th in passing yards allowed, ninth in interceptions and 25th in rushing and scoring defense. Led by super-sophomore defensive end Joey Bosa, who ranks fifth nationally in sacks per game, the Buckeyes have been very disruptive.

Despite their improved play, the Buckeyes haven't come close to reaching their ceiling defensively.

They're still susceptible to the occasional big play—which Cincinnati took advantage of in Week 3 by connecting on three long touchdown passes—and they can wear down late—which almost cost them last week against Penn State and its late rally.

With that said, Meyer knows that his team is close to reaching the dominant level he envisions.

If the Buckeyes can reach it soon, they could shoot up the rankings.

Consider Michigan State, which at this point last year was unranked with the same 6-1 record as the Buckeyes. The Spartans used a dominant defensive stretch to climb the BCS standings, allowing just 9.2 points per game in their final five regular-season matchups.

A 34-24 victory over Ohio State in the Big Ten title game vaulted Mark Dantonio's squad to a No. 4 ranking ahead of bowl selections.

It's hard to imagine the Buckeyes being that good, but if they continue to improve, they could see a similar rise in the polls.

All stats via NCAA.com.  

David Regimbal covers Ohio State football for Bleacher Report. Follow him on Twitter @davidreg412.