No other team has faced the no. 2 that Ohio State has this season. At home on Saturday, the Buckeyes will face their third top-5 opponent, taking on undefeated Indiana (10-0) in the biggest football game in Hoosiers history.

Under Hoosiers head coach Curt Cignetti, Indiana is off to its best start in school history. With an explosive offense averaging 43.9 points, Indiana dominated most of its opponents.

However, the Hoosiers haven’t faced a team of Ohio State’s caliber. Indiana’s most notable wins came against Michigan (5-5) and Washington (4-4), teams that look nothing like the schools’ football playoff teams from last season.

Instead, the Buckeyes lost at No. 1 Oregon 32-21 on Oct. 12 and have since outscored opponents 117-37 — that span includes a 20-13 road win over then-No. 4 Penn State. Thanks in large part to a defense that has allowed just 10.3 points per game, Ohio State leads the nation in margin of victory (27.5).

With a trip to the Big Ten Championship game — and perhaps the College Football Playoff — on the line, the stakes for the Buckeyes couldn’t be higher. Their key to a victory will rest largely on one major factor: defense.