Which playoff hopefuls are in good shape? CFP history has some answers

The College Football Playoff selection process is, by human nature, subjective. A group of 13 people select the top four teams using guidelines, not weighted criteria. Quite simply, it's up to them.

There have, however, been trends over the past three years -- statistical evidence from the 12 semifinalists that helps determine a top-four team in the eyes of the committee. Based on that data, compiled by Jason Starrett of ESPN's Stats & Information group, here's a look at which CFP front-runners from Power 5 conferences with one loss or fewer are in good playoff shape at the midpoint of the season -- and who's in trouble:

Schedule, schedule, schedule

All 12 CFP semifinalists played a regular-season schedule ranked among the top 55 in the FBS (average 27th).

Bodes well for: Pac-12 and Notre Dame

Notre Dame and USC, two one-loss teams that will play each other on Oct. 21 (before the first official ranking is revealed on Oct. 31), are both projected to have a final regular-season schedule ranked in the top 10 of the FBS. Wow. If either can win out, it's sure to impress the selection committee, especially since neither has a bad loss. USC is projected to finish fifth overall in strength of schedule, while the Fighting Irish are projected at No. 8. Don't forget, the Pac-12 plays nine conference games, not eight. For all of the criticism that Washington and Washington State have received for their weaker nonconference lineups, they are expected to finish with the No. 48 and No. 45 overall schedules, respectively.

Doesn't bode well for: Big Ten

Good luck, Wisconsin.

It's not the Badgers' fault, really. Their toughest nonconference opponent, BYU, is 1-5. And because of the Big Ten's cross-division scheduling rotation, Wisconsin avoids Ohio State, Penn State and Michigan State during the regular season. Wisconsin does play Michigan, which is the Badgers' only opponent currently ranked, but there's no guarantee the Wolverines will stay there.

Wisconsin's nonconference schedule is ranked 98th, according to ESPN, but it gets worse for the Big Ten: Penn State's nonconference schedule is ranked 117th. It certainly doesn't help the Nittany Lions that they were all home games, and Pitt -- expected to be the "marquee" opponent of the bunch -- is 2-4.

As of now, Penn State will play three straight ranked opponents after its bye week: No. 17 Michigan, No. 9 Ohio State and No. 21 Michigan State. The question is whether those three opponents can stay ranked by the committee through Selection Day.

While the selection committee has shown us it isn't handcuffed to precedent, strength of schedule is one thing it hasn't deviated from. That's a problem for Penn State and Wisconsin, currently the two highest-ranked teams in the Big Ten and front-runners in their respective divisions. According to ESPN's Football Power Index, Penn State is projected to play the 57th-ranked schedule and Wisconsin the 61st, both the worst SOS rank of any CFP qualifier to date. (Washington ranked 55th last season.) If either team wins the Big Ten but is left out, this will be why.

Eleven of the 12 participants played a regular-season nonconference game against a Power 5 opponent and won.

Bodes well for: Alabama, Clemson, Georgia, TCU, Oklahoma

The Crimson Tide's season-opening win against Florida State counts. The selection committee will recognize FSU was a different team with Deondre Francois as its quarterback. Clemson is arguably in the best shape after its win over Auburn, and TCU will get credit from the committee for beating Arkansas on the road. Georgia's win at Notre Dame -- no matter that it was by one point -- continues to look better as the Irish keep winning. Oklahoma's win against Ohio State in Columbus remains critical to its playoff hopes, but the Sooners have to win out for it to matter.

Doesn't bode well for: Wisconsin, Ohio State, Auburn

Ohio State and Auburn lost the opportunities to separate themselves from other potential Power 5 conference champs when they lost the only big games on their nonconference schedules. Wisconsin played two Group of 5 teams that are both currently 3-3 (Utah State and FAU) and a 1-5 BYU team.

Eye-opening wins

All 12 participants entered bowl season with at least two wins over AP-ranked opponents.

Bodes well for: Clemson

The Tigers are currently the only top-25 team that already has two wins over AP-ranked opponents, in No. 10 Auburn and No. 15 Virginia Tech. Louisville has since dropped out of the top 25, but Clemson now has another opportunity for a road win against a ranked opponent in No. 20 NC State on Nov. 4. The Tigers also will likely face a ranked opponent in the ACC championship game, assuming they're not upset in Raleigh.

By the end of the season, this trend should again hold true for the 2017 semifinalists, but the Tigers are the only ones who can already check this box.

Quarterback continuity

Nine of the past 12 semifinalists returned their primary starting quarterback from the previous season.

Bodes well for: Almost everyone. It's the Year of the Quarterback, remember?
Doesn't bode well for: Clemson, Georgia

Alabama is the only team that has been able to buck this trend -- for three straight years. Clemson has gotten through the most difficult stretch of its schedule with rookie Kelly Bryant, who has drawn praise from just about everyone, including his predecessor, Deshaun Watson. Bryant has already won on the road, and in prime time, but can he do it in a semifinal? In Atlanta? Georgia faces similar questions with Jake Fromm, who replaced injured starter Jacob Eason; Fromm seems to have earned the position permanently. Fromm erased many doubts when he won at Notre Dame, but can he do it against Auburn and possibly Alabama in the SEC championship game? Bigger tests lie ahead for both.

Coaching pedigree

Eleven of 12 participants had a head coach who had previously won a conference title.

Bodes well for: Alabama, Clemson, Penn State, Washington
Doesn't bode well for: Georgia

So far, the only exception was Oregon's Mark Helfrich, who was in his second season as a head coach in 2014. Georgia's Kirby Smart also is in his second season. Florida has won the SEC East during each of the past two seasons, and Missouri won it in 2014. Smart knows how to win a national title: He helped Alabama earn its last one. But can he beat Alabama to earn his own?

Here are a few other CFP trends from Starrett at ESPN's Stats & Information Group to keep an eye on in the second half of the season:

Bounce back from losses

Nine of the 12 participants reached the playoff with one loss, but all nine of those teams earned at least one more win against an AP-ranked opponent before bowl season. Here's a look at the top one-loss teams and the biggest game remaining on each one's regular-season schedule:

No. 9 Ohio State: Oct. 28 vs. Penn State
This game is likely to determine the Big Ten's East division winner.

No. 10 Auburn: Nov. 25 vs. Alabama
If the Tigers win the Iron Bowl, nobody will remember the loss to Clemson.

No. 12 Oklahoma: Nov. 4 at Oklahoma State
It doesn't carry the same weight many thought it would entering the season, but it will still eliminate the loser from the CFP.

No. 13 USC: Oct. 21 at Notre Dame
If the Trojans can't win this one, a Pac-12 title probably still wouldn't be enough for a top-four finish.

No. 14 Oklahoma State : Nov. 4 vs. Oklahoma
This is the only game left on the Cowboys' schedule that they're not favored by FPI to win.

No. 15 Virginia Tech: Nov. 4 at Miami
This game could determine the Coastal Division winner, unless Georgia Tech has something to say about it.

No. 16 Notre Dame: Oct. 21 vs. USC
This is the first of back-to-back ranked opponents for the Irish, as they face NC State on Oct. 28.

No. 17 Michigan: Nov. 25 vs. Ohio State
Jim Harbaugh is 1-4 against rivals Michigan State and Ohio State. If the postseason isn't on the line, that record sure is.

No. 20 NC State: Oct. 28 at Notre Dame
Many are already looking to NC State's game against Clemson, but if the Wolfpack can't beat the Irish, even winning the ACC probably won't be enough.

Great overall résumé

Eleven of 12 participants were ranked in the top four of ESPN's Strength of Record metric entering bowl season, including all eight teams over the past two years. The one exception? Ohio State in 2014, which was ranked No. 6 but still leapfrogged Big 12 co-champions TCU (fourth) and Baylor (fifth).

Win big

Ten of the 12 semifinalists entered bowl season ranked among the top 10 nationally in average scoring margin. The only exceptions were Florida State in 2014 (23rd) and Michigan State in 2015 (32nd).

Heisman hopefuls

Eleven of 12 participants had a player finish in the top 10 of the Heisman Trophy voting, including two teams with winners: Oregon's Marcus Mariota in 2014 and Alabama's Derrick Henry in 2015. The only exception was Ohio State in 2016.