Conference championships matter. Head-to-head matters. Strength of schedule matters. Every game counts, though some seem to count more than others and good luck figuring out which ones count most.
This and more is what the College Football Playoff selection committee sorts through to pick the four best teams in the country.
If consistency, certainty and clear-cut criteria are what you crave, this may not be the sport for you. Yes, the goal posts move from season to season. That may be the way it is for awhile - at least until the playoff grows up.
''Every year is going to be different,'' CFP executive director Bill Hancock said. ''Football seasons are like snowflakes, they're all different. Next year we'll be standing here talking about some other way it fell out. And that's great.''
It worked out great Sunday for Alabama, Clemson, Ohio State and Washington. Not so great if you root for Penn State.
No. 1 Alabama (13-0) will face No. 4 Washington (12-1) in one semifinal and second-seeded Clemson (12-1) meets third-seeded Ohio State (11-1) in the other on Dec. 31.
The committee stayed with the same top four it picked going into championship weekend, leaving out No. 5 Penn State (11-2) even though the Nittany Lions won the Big Ten title game and beat Ohio State earlier in the season.
The Buckeyes are the first team to reach the playoff in its three-year history without winning their conference.
Many questioned why Ohio State deserved a spot, especially over Penn State. Selection committee chairman Kirby Hocutt made it clear that the 12-person committee did not.
Ohio State's three victories against top-10 teams (No. 7 Oklahoma, No. 8 Wisconsin and No. 6 Michigan) and only one loss, by three at Penn State, won the day over the Nittany Lions. Penn State lost to Pitt and Michigan (by 39) before closing the season with nine straight victories.
Several times, Hocutt cited Penn State's noncompetitive loss and Ohio State's strong nonconference victory at Oklahoma.
So the key is to play a difficult nonconference schedule?
Well, maybe not.
The final spot came down to Penn State (11-2) and Pac-12 champion Washington.
The Huskies' only loss was to 10th-ranked Southern California and its nonconference schedule featured FCS Portland State, Rutgers and Idaho. Penn State played Pitt, Temple and Kent State out of conference.
''I think because of Washington's strength of schedule, their margin for error was very slim,'' Hocutt said. ''I think our discussions and our decision would have been much easier if Washington would have had a stronger strength of schedule this college football season.''
You could say Washington benefited because it did not play a difficult nonconference opponent. But you can also say that if Penn State beat Pitt it would have benefited from playing a difficult nonconference schedule.
Hocutt said the committee dug deep into the Huskies and Nittany Lions.
''As we looked at those key statistics from an offensive standpoint, from a defensive standpoint, from starting field position differential, the edge was to Washington,'' Hocutt said. ''You look at turnover margin, Washington ranks first in the country in turnover margin compared to Penn State, ranking 50.''
If there is a pattern to be found in the committee's work over three years it may be this simple: For the most part, the teams are ranked by the number in the loss column.
No two-loss team has made the playoff. Even a close head-to-head win over Ohio State and a conference title was not enough for Penn State to overcome two losses.
Maybe next season will be different.
In many ways the College Football Playoff is no different than the Bowl Championship Series, a highly subjective system that relied on poll voters to pick the top two teams. The one crucial difference, though, is enormous. Four instead of two makes the CFP better than the BCS.
What could provide more consistency, more objectivity while removing much of the subjectivity, is bigger playoff. Eight teams, with five automatic qualifying Power Five conference champions, the best team from the Group of Five and two wild cards. Fewer debates, plus it could put some juice back into championship weekend, which has become a little anticlimactic.
It would also bring Cinderella into college football's postseason, providing an opportunity for a non-Power Five team to win a meaningful postseason game and an underdog conference championship game winner to move on and play for the national title.
Sounds interesting, but it is not happening anytime soon.
Hancock said expansion of the playoff is not up for consideration by the conference commissioners. The CFP is in year three of a 12-year television deal with ESPN.
Clemson coach Dabo Swinney cautioned that more postseason would lessen the value of the regular season and that adding another round would require eliminating other games.
''I don't think you can go past 15 games in college football,'' said Swinney, whose did just that last season and lost to Alabama in the national championship game. ''Something would have to give.''
Ohio State's Urban Meyer said he empathizes with Penn State and would not mind seeing a system that rewards all conference champions.
''I'm not sure there's an easy answer,'' said Meyer, who has won two BCS championships and the first College Football Playoff. ''I think we're heading in the right direction.''
Follow Ralph D. Russo at www.Twittre.com/ralphDrussoAP
More AP college football: www.collegefootball.ap.org