Lou Holtz's best Irish teams utilized the triple-option as their chief mode of offensive transportation. Charlie Weis' five seasons employed a "Pro Style." And though it offered little resemblance to the successful version perfected by Bill Walsh's San Francisco 49ers in the 1980s, even Tyrone WIllingham's struggling side of scrimmage received a label, "West Coast Offense."
For Brian Kelly, and especially his 2012 Irish offense, only one word fits: multiple.
The Irish alternately employed two, even three tight ends, two perimeter receivers and a slot receiver, three receivers coupled with a tight end and a running back, and at times, two 'backs with one motioning to the slot or perimeter positions.
But one of the above was the preferred, most often utilized offensive set: the team's 12 package, or two tight ends.
"Coach Kelly and coach (Chuck) Martin's offense, the tight ends see that there's opportunity," said the position's coach, Scott Booker. "Now we have to take advantage of it. We have to show we're able to play all those positions (involving tight end such as detached, in-line, etc.).
"They're responding great. It doesn't take me to tell them we lost a special guy in Tyler (Eifert). Those guys have to step up. We can't wait until August to step up, it has to be right now."
Among those in need of progress is 2012 surprise Troy Niklas, who after a freshman season spent at outside linebacker, finished tied for sixth on the squad in total pass targets (11), was one of five players to catch a touchdown pass, and one of just two to draw a pass interference call from the defense (Eifert drew the other six; no Notre Dame wide receiver drew a flag from an official last season).
"He can be as good as he wants to be," said Booker of Niklas. "He has a lot of qualities as far as height (6'7"), his body control is good, hands are good. He comes to work, has a great work ethic, practices hard, I'm excited about his progress."
Niklas emerged last season due in part to the absence of Alex Welch. Now a senior, Welch missed last season after tearing his ACL in August camp. Most forget Welch was ahead of Niklas on the depth chart at the time of his injury.
"He was playing physical. He was creating another line of scrimmage," said Booker of what pushed Welch ahead in the pecking order. "He was really physical.
Just over seven months removed from surgery, Welch has been an active participant this spring.
"We're excited to see his leg is taking the pounding of pads," said Booker of Welch. "He's getting more confidence in his leg every day, he just has to get back to where he was in August (2012) and it won't be the first or second practice where he gets back all his technique.
Asked if the plan for Welch's spring was to progress enough for full competition and a potential starting role in the fall, Booker offered, "It's not a hope, that's what we're going to progress to. We saw what he was capable of doing, and we're going to get back to that, but it is a process."
Production Lacking, or in Waiting?
Welch was withheld from action as a 2010 freshman, then caught just one pass as the team's No. 2 tight end in 2011. Niklas secured just five last fall while his classmate Ben Koyack caught three of the six thrown in his direction, dropping two others.
The latter reality seems an aberration for Scout.com's No. 1 rated pass-catching tight end in the 2011 class.
"He has a lot to work on in spring and we have about 35 more practices before Temple, but Ben is doing a good job getting from point A to point B, he has really soft hands," said Booker. "He has to continue to be physical because we need all-around tight end play from each of them. We're not looking for one guy to be the catching tight end, one guy to be the blocker. We're looking for all-around tight ends."
Niklas has five career catches and struggled at times in pass protection. Koyack has four, struggling throughout the season as a run-blocker, at least vs. quality defenses. Welch has one catch and has played football in just one of the last three seasons entering his senior year (he's eligible through 2014).
Considering Eifert was targeted for 96 passes last fall and broke program records for yards and receptions by a tight end -- both single-season and career -- its clear the veteran trio has sizable shoes to fill.
And they have young talent champing at the bit behind them.
"I'm excited that he's coming to work every single day," said Booker of his early enrollee freshman tight end Mike Heuerman. "He should be preparing for prom right now but he's out there working, competing. He has a great work ethic to get better and he has a nasty streak about him. I know (strength an conditioning) coach (Paul) Longo has done it with numerous guys before: got them in his weight program to get them stronger, and Mike will do the same thing.'
Lauded by Kelly for his work ethic, Heuerman's spring will likely give him a Year One leg up on fellow freshman Durham Smythe, set to arrive on campus this summer.
"I would say that I'm really impressed with Mike," said Kelly. "He's put on almost 15 pounds. He's up to close to 230 pounds. He's got a burst to him. He's going to be a really good player for us."
They usually are.