The trickiest and most important decision of this college football season could boil down to three words.
Strength of schedule.
In the equation that determines which four teams reach the playoff, whom you play, and where and when you play them, can make all the difference.
It's part math, part mystery.
As Kirby Hocutt, a member of the College Football Playoff selection committee, put it: "Winning tells us a lot, but does not tell us everything."
So, after a weekend in which No. 4 Texas A&M lost a shocker, No. 5 Washington won big and No. 6 Ohio State won even bigger, the postseason picture remains very much undecided.
"I think it's good," Washington Coach Chris Petersen said, offering a positive outlook on his team's uncertain position. "They put us outside the top four and they make us earn it."
For now, at least, the top three teams look fairly solid with Alabama muscling its way past Louisiana State and Clemson and Michigan winning by wide margins. Though all have potentially tough games ahead, they should hold their places in the new CFP rankings on Tuesday.
The focus will be on that fourth slot.
Last week, the selection committee raised eyebrows when it placed one-loss Texas A&M above undefeated Washington.
"Washington is a well-balanced team … but in the committee's mind, Texas A&M has played a stronger schedule," Hocutt said at the time.
Critics of that decision — there were more than a few — took some vindication in the Aggies' 35-28 loss to a mediocre Mississippi State team on Saturday.
"If anything, we knew that people still weren't giving us the respect that we thought we deserved and we tried to go out there … and prove that," Texas A&M receiver Christian Kirk said. "Obviously we did not do what we needed to do."
Washington took care of business with a crushing 66-27 win at California, which on any other weekend might have clinched No. 4. But one-loss Ohio State may have scored more points with the selection committee by dismantling No. 10 Nebraska, 62-3.
Which raises the question: Will the Huskies get leapfrogged by a team with a worse record for the second-consecutive week?
The answer could depend on strength of schedule, a single phrase with multiple and sometimes murky components.
Consider that athletic departments often arrange their nonconference schedules well in advance. Sometimes a respected opponent can turn into a walkover five years down the line.
Washington cruised through the early season against Rutgers, Idaho and Portland State. Ohio State started with underdogs Bowling Green and Tulsa, then convincingly won a marquee matchup against Oklahoma.
After that came the conference schedule. The selection committee insists overall conference strength does not influence the rankings, but it does affect the quality of opponents a team faces from week to week.
Washington's victory over then-undefeated Stanford — impressive in the fifth week — lost its luster when the Cardinal dropped two of the next three. A subsequent win over Oregon now means less because the Ducks, who started the season at No. 24, have also faltered.
While the Pac-12 has struggled as a whole, the Big Ten has excelled.
Ohio State owns conference victories over ranked teams Wisconsin and Nebraska, the latter of which was probably overrated but still has a decent resume.
The Buckeyes even caught a break on their loss to Penn State, which the selection committee quickly elevated in last week's initial rankings.
"Penn State is a team that has improved as the season has gone along, so the committee was very confident that we had Penn State placed at the right spot at No. 12," Hocutt said.
When the CFP committee gathers to vote each week, the discussion touches upon head-to-head competition and common opponents. But there is another, somewhat murkier issue at play.
Committee members insist they ignore margin of victory. Yet Coach Bobby Petrino suspects his Louisville team, standing at No. 7 with one loss, was penalized for close calls against Duke and Virginia.
"I don't understand why it's like that," Petrino said. "I really don't."
In the scramble for No. 4, various websites — using various computations — rank Ohio State's strength of schedule higher than that of Washington or Louisville.
Looking forward, the Cardinals do not have much left on their schedule. Washington could bolster its case against a revitalized USC on Saturday and at No. 25 Washington State in the regular-season finale.
There is also the possibility of an appearance in the Pac-12 championship game.
But Ohio State could receive the biggest boost down the stretch. First the Buckeyes face No. 3 Michigan and then, potentially, another ranked team in the Big Ten title game.
"We're starting to put it all together," Coach Urban Meyer said. "And I'm glad it's happening now."
Right when the CFP selection committee is paying close attention. When strength of schedule counts the most.