Can Iowa football's defense get the worst out of Wisconsin's Graham Mertz?

Kennington Lloyd Smith III
Des Moines Register

It would be difficult to rank Iowa's great defensive performances throughout coach Kirk Ferentz's tenure, but last Saturday's effort in a 24-3 win over Purdue certainly stands out in recent memory.

The Hawkeye defense got the best of the Boilermaker offense, one that's been a particular thorn in their side in the last several years, holding Purdue to just three points, 255 total yards and 12.5% third-down conversion rate (2-for-16). And Phil Parker's defensive group completely shut down Purdue quarterback Aidan O'Connell.

Iowa held O'Connell without a touchdown pass, 168 passing yards, a 47% completion percentage and two interceptions. That's a far cry from the 324 passing yards per game that led the Big Ten.

The Hawkeyes have made a habit of forcing opposing quarterbacks into uncharacteristically bad performances. This Saturday, against another foe that has given them trouble in Wisconsin, the Hawkeyes must knock another quarterback off his mark in order to win.

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The re-emergence of quarterback Graham Mertz has given the Badgers a balanced offense. His raw passing output (1,707 yards) isn't eye-popping but he is ranked second in the Big Ten in passing touchdowns (17) and is third in quarterback rating (159.6). And under interim coach Jim Leonhard, a four-game stretch, he has nine touchdowns to one interception. He was labeled as a question mark entering this season after an underwhelming 2021 campaign but the third-year starter seems settled in this year.

"He's a veteran quarterback now, he's had a lot of snaps, a lot of experience," Iowa linebacker Jack Campbell said. "I feel like he's gotten better in the pocket. I feel like they're trying to do some different things with him to try to get out of the pocket, allow him to make plays with his legs if it's there but also make plays with his arm. He's a very talented guy."

Mertz, a former five-star recruit, is playing closer to those expectations this season but it's still a legitimate question of which version of Mertz will show up on Saturday. He's passed for 200-plus yards six times this season, more than all of last season, but there have been five games this season in which he was a sub-60% passer. Wisconsin is 1-4 in those games; and five of his six interceptions have come in those games.

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Will Iowa see the good Graham Mertz or the bad one on Saturday? That mostly depends on the defensive performance and the multi-layered strategy needed to make him uncomfortable.

"You can't let him get comfortable, starts there," Ferentz said. "He can make every throw there is. It's going to be a challenge. They have the ability to be balanced and the ability for play action. He certainly knows what he's doing. He's got a good feel for the game. Hopefully we can get him off his spot a little bit so he doesn't get comfortable."

Iowa's defense will look to contain Wisconsin QB Graham Mertz, who is second in the Big Ten in passing touchdowns (17).

Per The Athletic's Scott Dochterman, the team with the most rushing yards has won 19 of the last 21 matchups. From that lens, Iowa's defense must limit Wisconsin's running attack to make its offense one-dimensional. It will be a challenge as sophomore running back Braelon Allen has 100-plus rushing yards in 14 of his last 18 games and senior Isaac Guerendo is an emerging No. 2 back with 186 yards in his last two games. In what's expected to be a cold-weather game, controlling the line of scrimmage on either side is critical.

"To me that's where defense starts," Ferentz said. "If you let a team just run the ball at will it's going to be tough to be any good ... It's going to be a challenge for us. Hopefully it'll be a challenge for them. We both have our work cut out. They have a really good offensive line. This will be, if not the best line, it's certainly one of the best lines we've seen this year. So it's going to be a good challenge."

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This year's Wisconsin offensive line isn't all-time great but still carries its traditional size advantage. The starting lineup averages 6-foot-6 and 314 pounds. The Iowa defensive line has done a good job of separating off blocks over the last few weeks and that must continue on Saturday, in addition to playing with pad level, one of the staples of Iowa's philosophy.

Iowa's defense leads the nation in yards per play allowed (3.85).

"It starts with getting getting underneath them and making them play down to my level," defensive tackle Noah Shannon (listed at 6-foot, 289 pounds) said. "Which a lot of guys like that size don't really like to do. Another thing is making sure I'm separated from the block because if not, it's not hard for those long arms to engulf me and hold me from behind. So making sure I'm able to create separation and get off blocks to increase my production too."

Wisconsin's offensive line is more vulnerable in pass protection. Mertz was sacked just 11 times all of last season but this year's line ranks 10th in the Big Ten with 20 sacks allowed. Iowa has accumulated 10 sacks in its last two games, primarily due to the front four's ability to win one-on-one matchups. If the Hawkeyes can force Wisconsin into frequent must-pass situations (especially on third down), there's an opportunity to create pressure and potentially mistakes through the air. Improving third-down defense and capitalizing on opportunities to create turnovers when presented are two areas Iowa's defense has focused on recently. Wisconsin's 42% third-down conversion rate this season (fifth in the Big Ten) is on par with the 40% rate against Iowa in the last five meetings.

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Iowa's defense has been the team catalyst all season and will need to be again on Saturday in order to break a trend of losses (8 of last 10 meetings) to Wisconsin. Affecting Mertz throughout the game is the key. How will the Hawkeyes do it? Campbell said there's no magic formula and it comes down to continuing to play up to the team's standard as the unit has done in the last two weeks.

"I would say just being able to do our job every single snap," Campbell said. "It sounds mundane but just making sure that we stay on top of what we need to stay on top of and not try to do anyone else's job but ours. I feel like that's going to be important and just challenge (Mertz), challenge him to throw into a tighter coverage than the norm or force him to make the third read rather than his first read. We have to contest him."