Wisconsin senior linebacker Chris Orr (54) sacks Northwestern junior quarterback (11) in the second half of the game on Sept. 28. Credit: Courtesy of TNS

Wisconsin’s defense is No. 1 nationally in scoring defense and total defense. It is No.1 in rushing yards and passing yards allowed per game. It is No. 1 in third-down and red zone efficiency.

At least the Badger defense leads only the Big Ten — and not the entire country — in passes defended and fewest 20-plus-yard plays allowed.

No. 3 Ohio State (7-0, 4-0 Big Ten) has fallen short of 40 points just once this season, scoring 34 against Michigan State’s No. 22 total defense. No. 13 Wisconsin (6-1, 3-1) will badger the Buckeye attack with its toughest challenge to date.

“This is the No. 1 defense in the country,” Ohio State head coach Ryan Day said. “We consider ourselves to be one of the top offenses in the country. [We’ll] find out where we’re at [Saturday].”

Day credits much of Wisconsin’s defensive success to coordinator Jim Leonhard, pointing to the leverage and drive the Badgers create on that side of the ball with their scheme.

Wisconsin utilizes a rare defensive front where linebackers stand in place of defensive ends to pin runs inside and provide an athletic pass-rushing threat to opposing quarterbacks. Typically only two or three true defensive linemen are on the field, as opposed to the four Ohio State and many other college football teams use.

Three linebackers provide the foundation for Wisconsin’s defense, combining for 34 percent of the team’s tackles, 49 percent of its tackles for loss and 67 percent of its sacks, as each compose the top three in those categories.

The troublesome trio is composed of redshirt seniors Chris Orr and Zack Baun and sophomore Jack Sanborn.

“Baun does a great job in one-on-one situations. He’s very active, powerful, especially in third down,” Day said. “Those [other] linebackers do a great job, as well, adding on or blitzing in different situations.”

When opposing quarterbacks manage to get the ball away against the Wisconsin pass rush, they complete only 44 percent of passes.

Redshirt junior safety Colin Wilder leads the team with five passes defended, but two fellow defensive backs lurk right behind him with four. 

“The secondary is very talented, as well,” Day said. “You have to hang onto the ball maybe a little bit longer than you want to.”

Ohio State’s No. 3 scoring offense is the first top-60 attack the Badgers have faced this season, however. Wisconsin has yet to face a Power Five passing offense with a completion percentage of at least 60 percent through the air.

Ohio State sophomore quarterback Justin Fields completes 71 percent of his throws, aided in part by his ability to escape the pocket and extend plays, sophomore wide receiver Chris Olave said. This could be crucial against a secondary putting up the numbers that Wisconsin’s is.

“It’s really good for us receivers,” Olave said. “He likes to keep plays alive with his feet. The scramble drill is in effect. Our second part of the route is very important.”

The Badgers’ No. 1 rush defense hasn’t faced an opponent in the top 40 for rush offense, either, and the Buckeyes rank No. 3.

Junior running back J.K. Dobbins is the only player in the Big Ten who averages more than 130 rushing yards per game outside Wisconsin junior Jonathan Taylor, who won the 2018 Doak Walker Award as college football’s best running back.

Ohio State’s offense and Wisconsin’s defense are providing the first true test for each other, and the result of their clash will have implications for the Big Ten and national title races alike.

Day said the key will be ball security, physicality and good situational football.

“It’s going to be a challenge for our guys,” Day said. “We have to answer the bell.”

The test begins at noon Saturday in Ohio Stadium.