Indiana safety Mark Murphy is sometimes told to close his eyes at practice, visualize success and picture interceptions and stops in the backfield. The exercise is no different from last season.

But, when he closes his eyes this season, he senses something different. This entire defense does.

“It’s funny,” Murphy told ESPN.com. “You can talk about the scheme and the 3-4, 4-3 and all that. But I think the biggest thing for us is actually the attitude and the effort."

That change wasn’t born from the Hoosiers’ upset win over then-No. 18 Missouri, where they limited the Tigers to 27 points and finished with 11 tackles-for-loss. It’s taken months for Indiana’s first-year defensive coordinator, Brian Knorr, to build. And it’s taken an offseason for these Hoosiers to start buying into it all.

Knorr could see from last season’s film and his players’ eyes in the spring that this defense was worn down. Losses, weak performances and criticism tend to build -- and, for the past three seasons, Indiana hasn’t once cracked the Top 100 in total defense or scoring defense. Heck, in the past 15 years, the Hoosiers never cracked the top 65 in either category.

Knorr’s initial focus centered on forgetting that past and rebuilding this unit’s confidence. Whether it was showing a motivating film right before kickoff (one filled with Missouri miscues and IU sacks) or challenging the younger players to motivate the seniors, players told ESPN.com that this squad’s mind-set is totally different from seasons past.

“Our confidence has gotten way higher,” defensive lineman Bobby Richardson said. “We’re a completely different team. The mentality of this whole defense is different; we have a whole new attitude this year.”

There's excitement around this defense now, but there's no singular cause for that transformation. Knorr switched to a 3-4 scheme, tried to play up to different players’ strengths and emphasized a more aggressive mindset. In some ways, that was the easy part.

But it was also all the little things: reinforcing the importance of visualization, improving communication, reiterating continued focus and challenging the underclassmen in practice. Each difference impacted other areas of Indiana’s defense.

“The good thing about young kids -- freshmen and sophomores -- is they don’t know any better,” Knorr said. “Our seniors have seen them, and they’ve been challenged a little bit by them. I don’t want to say our younger guys led, but I guess they motivated some of our older guys.”

Richardson agreed. When the scout team breaks out of their practice blocks as if a game’s on the line, the upperclassmen no longer have time to relax. If they don’t play with that same intensity, they’re asking to look foolish. That’s clearly paid off for both groups; it’s no coincidence that freshman linebacker Tegray Scales was recently named Big Ten co-Freshman of the Week.

Of course, that’s not to say this Indiana defense has already matured into a great one. It hasn’t. It might even be fair to say it’s still working on being average. But Knorr is the first to admit this defense has a long way to go. Regardless, it’s clear something has changed.

Richardson answered most questions about 2013 by talking passionately about 2014. Murphy deflected every question about past seasons -- except when asked why he didn’t want to answer them.

“You really don’t want to talk about it because it’s just so, so -- different,” he said. “It’s just not comparable.

“The biggest thing for this year compared to last year is that we put it upon ourselves to go make that change, to make the difference. Because, ultimately, we were sick and tired of hearing about offense, offense, offense. We knew we had the talent and the players.”