This is the big one. The first ever meeting with both teams ranked. An outside chance at a Pac-10 title and a shot at BCS eligibility hang in the balance. It’s the biggest remaining obstacle between the Cardinal and an 11-win season. ABC is airing the game in primetime, with its top team of Brent Musberger, Kirk Herbstreit and Erin Andrews on hand. The winner will likely jump into the top 10, while the loser must aim for the Alamo or Holiday Bowl.

Yet in a sense, Stanford and Arizona still bring major question marks into Saturday’s top-15 clash.

Sure, both the Cardinal and the Wildcats are ranked in the top 13 in both the polls and the computers. Sure, the teams are led by two of the nation’s top quarterbacks. Sure, Stanford has already matched up with the No. 1 team in the country, holding a first-half lead in Autzen Stadium and making Oregon sweat much more than the final 21-point margin would indicate. Sure, Arizona owns one of the biggest nonconference wins in the country, a thrilling seven-point win over then-No. 9 Iowa.

But in many ways, both teams have a lot to prove. Consider the most talked-about matchup of the game: Stanford’s high-powered offense against Arizona’s stingy defense.

The basic statistics touted by most analysts paint this battle as a clash of the titans. The Cardinal offense ranks fifth in the country in scoring, averaging over 42 points per game, while the Wildcats rank seventh in scoring defense, allowing fewer than 15 points per game. As the saying goes, something’s gotta give.

Looking at the schedule, though, neither the Stanford O nor the Arizona D has been remotely challenged in most of its contests. Among the Cardinal’s first seven opponents (disregarding FCS Sacramento State), only one ranks in the top half of the country in scoring defense. That one was Oregon, which shut Stanford out in the second half after the Cardinal jumped out to an 18-point first-half lead. Meanwhile, Stanford racked up points against Wake Forest, Washington State and Washington, who all sit in the bottom 15 nationally in points allowed.

This same phenomenon has influenced Arizona’s statistics. The Wildcats have faced four opponents (other than FCS Citadel) ranked worse than 75th in scoring offense, allowing only 11 points per game to them. On the other hand, Arizona has faced three decent offenses—Cal, Oregon State and Iowa. The Wildcats held Cal to only nine points, but the Golden Bears have been abysmal on the road this season, losing all four games away from Memorial Stadium. The other two had relative success against Arizona’s defense, scoring at least 27 points in each game.

Now, no reasonable college football fan would say that Stanford has a poor offense or that Arizona has a poor defense. Each unit will likely be the toughest test the other has faced this season. But neither unit has been able to consistently perform against a strong opponent, which is what makes this matchup so intriguing.

Apart from this facet, Saturday’s showdown could expose more untested areas of each team. The Wildcats will be facing their first real road test of the year. Coming in, the only games Arizona has played away from home have been against Toledo, Washington State and UCLA. While the Rockets have done well in MAC play, they were two-touchdown underdogs to Arizona, and the Cougars and Bruins have set up shop in the Pac-10 cellar. Stanford represents a significant step up in competition level.

Overall, Arizona has played five Pac-10 opponents, including the bottom four teams in the conference. The only winning conference team the Wildcats have played is Oregon State, and the Beavers beat Arizona in Tucson. The Wildcats have ascended to the top 15 without playing Oregon, Stanford or USC, so their true ability remains in question.

Meanwhile, Stanford has played only two teams with winning records, losing to Oregon and squeaking out a victory over USC at home. Arizona is on a different level than the Trojans, so the Cardinal will certainly need to step up its play to contend with the Wildcats.

In addition, both teams have to deal with their own internal question marks. Stanford’s defense has been incredibly inconsistent—see: two road shutouts in Pac-10 play, but 38.3 points per game allowed in a three-game stretch against Oregon, USC and Washington State. The performance of the Cardinal defense, particularly against the pass, could be the deciding factor on Saturday night. Arizona has its own uncertainty at quarterback, where starter Nick Foles has been sidelined by a knee injury for the past few weeks. Backup Matt Scott has performed admirably in his absence, but the Wildcats will need their best offensive effort to keep up with Andrew Luck and the Stanford offense.

For both teams, the spotlight and pressure are relatively new phenomena. Arizona has never made the Rose Bowl, while Stanford’s players were still in elementary school the last time the Cardinal smelled roses. However, both Mike Stoops and Jim Harbaugh have changed the attitudes at their respective schools, and both teams figure to be up for the challenge.

The hype about Arizona-Stanford will be all about the strengths of both teams, but it will be each team’s weaknesses, and its ability to improve on them, that will decide this one.

Jacob Jaffe loves stats. Teach him something new at jwjaffe “at” stanford.edu.