SOUTH BEND, Ind. – In the aftermath of Notre Dame's blowout loss to Alabama in the BCS championship game, Irish coach Brian Kelly vowed to review all aspects of the program in an effort to make that final step toward a national title. Considering the 42 points the Crimson Tide hung on him that night, it certainly included the defense.

Take out the Alabama debacle, however, and Notre Dame allowed just 10.3 points a game last season. That included just six (coupled with forcing six turnovers) in a victory over Michigan, which will play host to the No. 14 Irish Saturday night in one of the big college rivalry games of the weekend.

So it's not like a full overhaul was needed. That only heightened the challenge. Where do you find an outside set of eyes with both the expertise to effectively analyze the specifics of the Irish defensive scheme, implementation and execution and the gravitas to have the entire program, from head coach on down, listen?

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Brian Kelly is 51, but he's still, at heart, a Massachusetts kid from blue-collar Chelsea. He was raised on Boston sports. He has a picture in his bright, spacious office here of him throwing out the first pitch at a Red Sox game last summer in Fenway Park, the Green Monster rising tall in the background behind him. "The ultimate," he beams.

Kelly is a football guy, of course, but when Bill Belichick began lining up Lombardi Trophies with the New England Patriots and cementing his reputation as football's best coach, Kelly was working at Division II Grand Valley State in Michigan. He lived a million rungs down the career ladder. Even as Kelly climbed – and Belichick held relationships with other college coaches – they never met until last February when both participated in the AT&T Pebble Beach National Pro-Am in California.

A fast friendship was formed, part based on football, part on golf and part on the passion shared by Kelly's wife, Paqui, and Belichick's girlfriend, Linda Holliday, for raising money in the fight against breast cancer. The Kellys quickly offered support to some charity events back in Boston. And Belichick said he'd come to South Bend for a couple of days in March to scout some Irish draft prospects.

And that's when Kelly made a bold request of his ideal program evaluator and perhaps found his secret advantage for the 2013 season.

"I asked him if he could spend some time watching games and we could discuss," Kelly told Yahoo! Sports. Belichick quickly agreed, and suddenly Notre Dame was about to get an overhaul from someone who most certainly knew what he was talking about.

For Belichick, this is the fun stuff. He was all for it.

"I just really enjoy talking football," Belichick said. "So much goes into the entire process that it's impossible to run out of things to work on – coaching, playing, practice, preparation, scouting, technology, how the whole structure fits together."

The process was particularly smooth. Bob Diaco, Notre Dame's defensive coordinator, previously worked as an assistant under Al Groh at the University of Virginia. Groh coached back in the day alongside Belichick on Bill Parcells staff of the New York Giants. Both Notre Dame and New England play a great deal of 3-4 defense.

"Bill is very aware of our defense because there's great similarities," Kelly said. "It was a great way for him to communicate some things with us using the same nomenclature to, 'Hey, have you thought about this?' "

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Belichick spent about a day and a half working with the Irish coaching staff, grinding through game footage, asking pointed questions, challenging assumptions … essentially being Bill Belichick. There was no fee. Belichick did get paid to speak at Notre Dame's coaches' clinic during that visit, although Kelly noted that doesn't command anything close to enough to make up for all the effort.

"It was a substantial amount of time for a guy like Bill Belihick to be involved watching and communicating with us," Kelly said.

It furthers Belichick's reputation as a football lifer with a passion for giving back to the game.

"It doesn't matter how long you've been at it, we are all still learning and trying to improve on something," he said.

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