College football teams go to great lengths to draw elite high school athletes to their programs. On National Signing Day Feb. 3, the day that recruits sign binding agreements to play for a college, University of Michigan head coach Jim Harbaugh raised the bar.

Harbaugh turned the day into a two-hour, sold-out show featuring appearances from Tom Brady, Derek Jeter, hip-hop group Migos and many other stars.

And it worked. The nation’s top recruit and top kicker, who had both been committed to Penn State, announced their commitments to Michigan toward the end of the extravaganza. 247Sports ranked Michigan’s 2016 recruiting class — a team’s new batch of players — No. 5 in the country, compared to Oregon’s No. 28.

University of Oregon athletic department spokesman Craig Pintens said other schools will emulate Michigan’s approach. But Oregon head coach Mark Helfrich said during his Signing Day press conference that he won’t follow Harbaugh’s approach in future years.

That doesn’t mean Oregon isn’t pouring resources into recruiting. From 2009 to 2013, Oregon spent the sixth-most nationwide on football recruiting and the most of any Pac-12 school.

To stay competitive, it will have to keep spending.

Oregon Ducks head coach Mark Helfrich walks out of the Moshofsky center to greet fans. The No. 18 Oregon Ducks face the Oregon State Beavers in the Civil War at Autzen Stadium in Eugene, Ore. on Nov. 27, 2015. (Cole Elsasser/Emerald)

“There are no spending limits, but the NCAA rules are very strict on recruiting, which curbs the amount spent on recruiting,” Pintens said via email.

The NCAA definition of recruiting expenses includes: “Transportation, lodging and meals for prospective student-athletes and institutional personnel.” The NCAA doesn’t allow schools to hire individuals “for the primary purpose of recruiting” or pay student-athletes’ expenses, except during official visits. Oregon spent $1,514,082 on recruiting — $708,675 on football — in 2015.

Due to these regulations, schools have to find different ways to attract the nation’s best athletes.

The facilities that Nike co-founder Phil Knight donated to the Oregon athletic department are designed to intrigue recruits, but don’t count toward the recruiting budget. Prospective and current Ducks frequently cite the $95 million Hatfield-Dowlin Complex and $42 million Jaqua Academic Center for Student Athletes as factors in their decisions to choose Oregon over other schools.

“As a recruit, to be able to step in there — I mean, if I had to do it all over again and I stepped in there, I’d tell coach [Chip] Kelly that I’d sign the paperwork then and there,” Marcus Mariota told 247Sports when the Hatfield-Dowlin Complex opened in 2013.

Knight’s latest facility gift is the 29,000-square-foot, $19.2 million Marcus Mariota Sports Performance Center, on which construction began in January. The center, which will include 3-D motion capture technology and a neurocognitive center to help diagnose and treat concussions, may be a part of Knight’s effort to keep Oregon ahead of the recruiting curve. Equipped with an “athlete fitting room,” the center is also a way to showcase Nike products to recruits, UO director of equipment operations Aaron Wasson said.

Oregon’s facilities set the pace for other schools.

Clemson University in South Carolina, for example, recently announced plans for a $55 million football complex that includes a mini-golf course and laser tag arena.

And when the University of Alabama added a waterfall to its weight room in 2013, Ohio State University followed suit with a waterfall of its own a few months later.

“If you’re not going to be paying a player as an employee, this is what you do,” two-time Pulitzer Prize winner Gilbert Gaul wrote in Billion Dollar Ball: A Journey Through the Big-Money Culture of College Football. “You just lavish on them all this other stuff.”

Athletic departments don’t always file recruiting-related expenses under their recruiting budgets.

The University of Tennessee spent almost $6.5 million on football recruiting from fiscal years 2009 to 2013 — nearly 40 percent more than any other major college program. But Tennessee vice chancellor and athletic director Dave Hart told USA TODAY Sports that Tennessee may not actually be spending more than other schools. Hart said Tennessee lists any recruiting-related expenses on its NCAA reporting forms, whereas other schools may put some of those expenses into other accounts.

The Oregon Ducks host Cal at Autzen Stadium on Nov. 7, 2015. (Cole Elsasser/Emerald)

Oregon, for example, lists the expense of “recruiting publications” under the non-recruiting category “Fundraising, Marketing and Promotions,” according to its 2015 NCAA Equity in Athletics Disclosure Act report.

Some recruiting efforts avoid the books altogether. Former University of Louisville graduate assistant coach Andre McGee paid for strippers to dance and have sex with recruits at parties at a campus dorm from 2010 to 2014, ESPN reported. The allegations prompted Louisville to self-impose a one-year postseason-ban on its men’s basketball team, amid an ongoing NCAA investigation.

Spending does not guarantee wins or a top recruiting class. But because so many recruiting expenses aren’t reported as such, there is no definitive way to compare the amount each school spends or whether those expenses correlate with on-field success.

What is clear, though, is schools will keep finding ways to out-do one another in order to impress high school athletes. As schools with the most resources up the ante, Oregon’s price to stay in the competition only gets higher.

Follow Kenny Jacoby on Twitter @KennyJacoby