It's worth noting that two of the four teams that made the College Football Playoff last season, Clemson and Georgia, each played two nonconference games against Power 5 opponents.

In fact, Clemson played Auburn and South Carolina, both of which were ranked in the CFP selection committee's rankings going into the final week of the regular season, and Georgia played both of its games on the road -- at Notre Dame and at Georgia Tech. And CFP participant Oklahoma played at Ohio State and won handily.

So maybe challenging nonconference schedules do matter.

With that in mind, we've ranked the 10 toughest nonconference schedules for Power 5 teams in 2018, and we haven't completely forgotten about the Group of 5 teams. A big shoutout to Florida Atlantic, Louisiana and SMU. Lane Kiffin's Owls play at Oklahoma and at UCF. Billy Napier's Ragin' Cajuns play at Alabama and at Mississippi State, and Sonny Dykes' Mustangs play TCU at home and then at Michigan in back-to-back weeks.

But as far as the 10 toughest Power 5 nonconference schedules, only three of the five leagues are represented. The Big Ten and SEC are noticeably absent. The ACC leads the way with four of the top five toughest slates out of conference and five of the top 10. The Pac-12 is right on the ACC's heels with four of the 10, and Texas is the lone Big 12 representative.

Here's how we ranked them:

1. Pittsburgh

Sept. 1 vs. Albany, Sept. 8 vs. Penn State, Sept. 29 at UCF, Oct. 13 at Notre Dame

The top spot was a no-brainer. The Panthers are the only Power 5 team to face three nonconference teams ranked in Mark Schlabach's latest Way-Too-Early-Top 25, including No. 12 Notre Dame and No. 18 UCF on the road. The trips to South Bend and Orlando are part of a stretch that includes three road trips in four weeks for Pitt, which also travels to face ACC foe North Carolina on Sept. 22. That's not to mention a home game with No. 13 Penn State the second week of the season.

2. USC

Sept. 1 vs. UNLV, Sept. 15 at Texas, Nov. 24 vs. Notre Dame

Just like a year ago, the Trojans take on two of college football's most storied programs out of conference. They travel to No. 22 Texas the third week of the season, coming on the heels of the Pac-12 opener on the road at Stanford. Talk about a grueling two-game road trip. USC then ends the regular season with a home date against No. 12 Notre Dame, which thrashed the Trojans 49-14 last season in South Bend.

3. Florida State

Sept. 8 vs. Samford, Sept. 22 vs. Northern Illinois, Nov. 10 at Notre Dame, Nov. 24 vs. Florida

The back half of the season for the Seminoles will certainly test their resolve. The road trip to No. 12 Notre Dame comes after back-to-back games against Clemson and North Carolina State, and means FSU will be on the road in successive weeks against NC State and Notre Dame. And two weeks after visiting South Bend, the Seminoles get archrival Florida at home at a time when the Gators should be finding their groove offensively under first-year coach Dan Mullen. Throw in Northern Illinois with a defensive front that should be nasty and Willie Taggart has a major undertaking outside the league in his first season in Tallahassee.

4. Clemson

Sept. 1 vs. Furman, Sept. 8 at Texas A&M, Sept. 15 vs. Georgia Southern, Nov. 24 vs. South Carolina

One of the more interesting September nonconference clashes nationally comes that second week when Clemson heads to College Station to take on a familiar face -- Jimbo Fisher, in his first season as Texas A&M's head coach. The Aggies are ranked No. 23 entering the season, and Clemson will close the regular season with its annual grudge match against archrival South Carolina, which is ranked No. 25. This should be Will Muschamp's best team since taking over the Gamecocks program.

5. Georgia Tech

Sept. 1 vs. Alcorn State, Sept. 8 at South Florida, Sept. 29 vs. Bowling Green, Nov. 24 at Georgia

Several ACC teams face challenging nonconference slates, and Georgia Tech cracks the top five thanks to two true road games. The Yellow Jackets play at South Florida the second week of the season, and even though the Bulls are losing star quarterback Quinton Flowers, Charlie Strong's club isn't lacking for talent. Georgia Tech closes the regular season against in-state rival Georgia, which played in the national championship game a year ago and enters the 2018 season ranked No. 4.

6. Arizona State

Sept. 1 vs. UTSA, Sept. 8 vs. Michigan State, Sept. 15 at San Diego State

There wasn't a lot of difference in some of the Pac-12's toughest nonconference schedules, but Arizona State claimed the top spot thanks to its home matchup with No. 9 Michigan State the second week of the season and then a road game the very next week against San Diego State. Rocky Long's Aztecs have won 10-plus games for three straight seasons, and even though Rashaad Penny is no longer around, junior running back Juwan Washington presents his own set of problems for ASU.

7. Stanford

Aug. 31 vs. San Diego State, Sept. 15 vs. UC Davis, Sept. 29 at Notre Dame

The Cardinal open the season against San Diego State, but it helps that the game is at home. It's a Friday contest, and then the next week, Stanford gets USC at home. So David Shaw's club will need to be sharp early. There won't be anything easy about the month of September for Stanford, which lost to both San Diego State and USC a year ago to start 1-2. The Cardinal close out September with a road game at No. 12 Notre Dame after playing at No. 24 Oregon the week before.

8. Texas

Sept. 1 vs. Maryland in Landover, Maryland, Sept. 8 vs. Tulsa, Sept. 15 vs. USC

The toughest nonconference schedule in the Big 12 belongs to Texas, which looks to improve on last season's 7-6 finish in what was Tom Herman's first season in Austin. The Longhorns open the season against what should be an improved Maryland team at FedEx Field. It's an 11 a.m. CT kickoff, which is never easy for a team traveling halfway across the country. Two weeks later, Texas takes on No. 17 USC at home. The two teams played a double-overtime classic last season, with the Trojans pulling out a 27-24 win.

9. Louisville

Sept. 1 vs. Alabama in Orlando, Sept. 8 vs. Indiana State, Sept. 15 vs. Western Kentucky, Nov. 24 vs. Kentucky

Any nonconference slate with Alabama on it is always a load. The Cardinals take on the No. 1 Crimson Tide in Orlando to open the season, and Nick Saban has lost only one regular-season game to a nonconference opponent while at Alabama, and that was in 2007, his first season, to Florida State. The Sept. 15 game against Western Kentucky could be tricky, and then there's the regular-season finale against bitter rival Kentucky, which returns 18 starters.

10. UCLA

Sept. 1 vs. Cincinnati, Sept. 8 at Oklahoma, Sept. 15 vs. Fresno State

The Chip Kelly era in Westwood kicks off with what should be an interesting first few weeks of the season. Looming large is that trip to No. 5 Oklahoma the second week of the season. The Bruins open against Cincinnati at home. But right after tangling with the Sooners on the road, UCLA returns home to face Fresno State, which won 10 games a year ago in Jeff Tedford's first season and should again be a player in the Mountain West Conference. The Bruins also play at Colorado and then are home against No. 6 Washington in their first five games.