Katy Perry likes a good dark horse.

So does college football.

There are numerous scenarios that could still unfold in the College Football Playoff race, and the pool for candidates is still deep -- like, top-25 deep. There are a few teams, though, that have started to raise a flag, saying, 'Hey, look at us!'

With so many upsets in Week 6, doors to the playoff have opened in every conference. Here's a look at one Power 5 team in each league with an outside shot at playing its way in:

ACC -- Georgia Tech: Paul Johnson had never beaten Virginia Tech and Miami in the same season. Until now. There are 10 undefeated teams left in the country, and the ACC has two of them -- defending national champ Florida State and Coastal Division leader Georgia Tech. Saturday's win over the Canes marked the first time in six years the Yellow Jackets beat Miami. They've earned some consideration, but they would likely have to win the ACC title to have a serious shot. The good news? They look like they're on the fast track to Charlotte, North Carolina.

Georgia Tech's spread-option offense ranks No. 1 in the nation in third-down conversions (58.1 percent); tied for No. 6 in the nation in turnovers (four); and No. 14 in the nation in time of possession (average 33 minutes). Equally as important is the fact there's nobody else in the Coastal Division who looks like they're gonna put up a fight. Pitt has given up 394 yards rushing in the past two games, and North Carolina has simply been abysmal. The Jackets don't have to play FSU this year, but they do have Clemson and the regular-season finale at Georgia. To think Georgia Tech will finish undefeated is a stretch, but a spot in the ACC title game is looking more realistic.

Big Ten -- Ohio State: The Buckeyes look like a sneaky playoff contender. The selection committee can't ignore the injury to quarterback Braxton Miller, and it could lend to some leniency by the 13-member group when evaluating the Buckeyes' 35-21 home loss to Virginia Tech in Week 2. It's the lone blemish on Ohio State's schedule, and it has looked worse since the Hokies lost back-to-back games after their upset. The committee, though, has said it will factor in injuries. It was the first home game of J.T. Barrett's career -- and he threw three picks.

Now? Barrett is actually on pace to have better passing numbers than Miller, he looks much more comfortable in Urban Meyer's spread offense and he's surrounded by a talented supporting cast that's helping him out. The question is whether or not Ohio State can win at Michigan State. The Buckeyes have to win the Big Ten to have a shot because, right now, the Spartans are the only ranked opponent on their schedule. They're going to have to overcome the loss to the Hokies and their own strength of schedule.

Big 12 -- TCU: TCU's upset of Oklahoma was the program's biggest win since it joined the conference in 2012, instantly vaulting the program from dud to dark horse. The Horned Frogs are one win away from leading the Big 12, but ESPN's Football Power Index ranks the game against Baylor as the most difficult remaining on TCU's schedule. (FPI gives Baylor a 71 percent chance of winning.)

That game will have the biggest impact on the College Football Playoff race because if TCU wins, both Baylor and Oklahoma will need the Horned Frogs to lose twice to have a shot at winning the conference.

TCU rose to No. 18 in FPI, and its odds of winning the conference have increased from nine percent to 23 percent. The offense has improved, and the defense held Oklahoma scoreless in the fourth quarter.

"We feel like we can win the Big 12 title," Horned Frogs quarterback Trevone Boykin told ESPN.com's Jake Trotter. "And I'm pretty sure if we win the Big 12, we'll have a shot [at the playoff]."

No doubt about it.

Pac-12 -- Arizona: From unranked to the top 10 in the Associated Press poll.

It's amazing what a win at Oregon can do.

Arizona has arguably the best win of the season, is the only undefeated team remaining in the Pac-12 and one of just 10 undefeated teams in the entire country. On a week in which Stanford, USC, Oregon and UCLA all lost, it's impossible not to give credit to the one team that has found a way to win -- even on a Hail Mary. The Oregon game was different than the thriller against Cal. Arizona looked like the better team for the majority of the game in Eugene, Oregon.

Remember, though, after Arizona upended the Ducks last season, it got trounced by Arizona State the following week, losing 58-21. Arizona faces USC next and still has UCLA, Utah and Arizona State on the schedule. There are plenty of opportunities remaining for Arizona to build its résumé and have more than a Hail Mary's shot at the playoff.

SEC -- Ole Miss: These dark-horse darlings captured the nation's attention with their stunning win over Alabama, but dig a little deeper and the Rebels give one big reason to believe they can keep it up -- defense.

The Ole Miss defense ranks fifth nationally, allowing just 277 yards per game. It's also the No. 2 scoring defense (10.2 points per game) and has allowed only four touchdowns, the fewest in the nation. Alabama was forced to punt six times after having punted just five total times entering the game. The Tide also entered the game leading the nation in third-down conversions and managed just 6-of-16 against Ole Miss.

Ole Miss hasn't won the SEC since 1963. In order to change that, it has to survive the country's toughest division, starting Saturday at Texas A&M, which has the most efficient offense in the nation and is projected by FPI to be the Rebels' toughest remaining game.

Notre Dame: The Irish have a chance to unseat a conference champ in the playoff if Notre Dame goes undefeated. In order for Notre Dame to go undefeated, it has to win at Florida State on Oct. 18 -- the most difficult game left on the schedule.

Notre Dame also has to travel to Arizona State and USC, but it already beat Stanford.

Notre Dame's defense, which had to replace seven starters from 2013 and under the direction of a new coordinator, is holding opponents to just 12 points per game. Quarterback Everett Golson has made enough plays to put his team in positions to win, and he's the kind of mobile quarterback who can give Florida State's defense headaches. Notre Dame has gotten to this point, somehow, in spite of many questions and an academic investigation that has sidelined five players.

Right now, the Irish are in the conversation. If they beat Florida State, they should be in the top four.