Every fall, the debate rages from coast to coast.

Fans of every major football conference claim their league is the strongest. If national championships mean anything, the Southeast Conference has probably been America’s toughest in this decade, and, top to bottom, could be again this season.

But when ranking the nation’s top QUARTERBACK conferences in 2008, no league has the depth of the Big 12.

Colt McCoy of Texas is at or near the top of most Heisman Trophy lists heading into Saturday’s showdown with Texas Tech’s Graham Harrell — a battle not only of Heisman contenders but also of the Big 12’s final two unbeaten teams. The winning signal-caller in Lubbock Saturday could very well become the clear-cut Heisman front-runner, and his team will take a huge step toward a national championship.

In any other year, McCoy and Harrell would be no-brainers to head the first and second teams — in some order — in the voting for All-Big 12 quarterback. This season, though, the depth at college football’s glamour position in the conference is unequalled anywhere else in the land and, quite possibly, in the history of the league.

The Big 12 is so filthy with quarterbacking talent, in fact, that a guy who is invited to the Heisman ceremony in New York later this year could very well be no better than third team in his own conference.

McCoy is the stylish pick as the first-team Big 12 quarterback at this point. He has completed an almost unfathomable 81.8 percent of his 242 passes this season, and he has thrown 21 touchdown passes and just four interceptions. In addition, he is the leading rusher — with just 412 yards — on a Longhorn squad that, despite ranking third in the conference is rushing yardage, doesn’t have a single back in the top 12.

If Texas wins Saturday and McCoy has a big day, he could very well wrap up the Heisman without playing another down, and if the Longhorns beat the Red Raiders and complete an incredible sweep of (then-No. 1) Oklahoma, (No. 9, formerly No. 3) Missouri, (No. 7) Oklahoma State and (No. 5) Texas Tech, Mac Brown’s team should by all rights be declared national champion without playing another game.

That won’t happen, of course. Even after Saturday’s latest Game of the Year in Lubbock, the winner — whoever it is — will still have a lot of football to play, including the Big 12 championship game and a date in the BCS title game in January against an opponent to be named later. At this point, Penn State appears to have the inside track to face whichever Big 12 heavyweight survives, with the Nittany Lions — who won’t have to play a Big 10 conference championship game — having passed their toughest regular-season test Saturday at Ohio State.

No matter who wins the Heisman Trophy and the national championship, though, the debate will drag on long after the season is over. Who really is the best quarterback in the Big 12 this season?

On pure numbers, Harrell is the clear front-runner. His 3,147 passing yards are not only almost 400 more than OU sophomore phenom Sam Brandford, but they also represent about 70 percent of Tech’s league-best 4,455 total offense for the season. Harrell has completed 71.1 percent of his passes and has thrown 28 touchdown passes with just five interceptions. His interception total is even more impressive considering his 371 pass attempts are 101 more than Bradford, who ranks second in the league.

Critics will point out that Harrell, like the other triggermen in Mike Leach’s high-powered offense over the past few seasons, is a product of a system that enables his quarterbacks to not only succeed but to excel. System or not, Harrell is having one of the best seasons in conference history, and Tech as a team is succeeding like never before.

Bradford’s stock dropped slightly Saturday, despite tossing three touchdown passes and directing an offense that rolled up 58 points in a 23-point victory at Kansas State. He was well below 50 percent for the day, and the Sooners scored just three points in the second half after piling up 55 (a school record for a half) before intermission.

Another knock against Bradford could be the fact that he is supported by the best running game among the league’s top quarterbacks. DeMarco Murry and Chris Brown rank second and fifth, respectively, among Big 12 running backs, and the Sooners rank behind only OSU, Baylor and Texas in league rushing.

On the plus side, Bradford has completed 67.8 percent of his passes for 2,775 yards, 29 TDs and 5 picks, and he also leads the highest-scoring offense (48.2 points per game) in a league where four other teams — Tech (48.0), Missouri (47.4), Texas (45.6) and OSU (43.6) — are averaging more than 40 points per game.

McCoy doesn’t come close to the passing yardage numbers of either Harrell or Bradford, but his completion percentage would be hard to duplicate if you just stood in the front yard and threw a football back and forth. He’s completed almost 82 percent of his throws while facing easily the toughest overall schedule of any team in the Big 12 through eight games.

In addition to his passing efficiency, McCoy is also a threat as a runner — something neither Harrell nor Bradford is really asked to bring to the table in their respective offenses. His hard-nosed approach to the game is reminiscent of old-time Southwest Conference and Big 8 quarterbacking greats like Bobby Layne and, more recently, Jack Mildren, and so far this season he’s done nothing but win — always a plus at Heisman time.

The forgotten quarterbacks in all the hubbub over the exploits of McCoy, Harrell and Bradford this fall are Missouri’s Chase Daniel and Kansas standout Todd Reesing, who each had a resumé to rival that of any of the “Big Three” when the season began. Disappointing efforts by their teams have caused their stock to fall significantly, however, and, despite strong individual numbers, neither figures to earn anything better than “honorable mention” when Big 12 honors are passed out at season’s end.

In Daniel’s case, his team’s disappointing season — at least based on preseason expectations — has been more a case of defensive failures than any real holes in the offense. Missouri has averaged 47.4 points per game, and Daniel ranks third in passing yardage (2,675) and touchdown passes (23) and has thrown just six interceptions, but losses to OSU and Texas have somewhat overshadowed another outstanding season by the former Southlake Carroll star.

Another forgotten guy in the Year of the Quarterback in the Big 12 is Oklahoma State’s Zac Robinson. He doesn’t have the pure passing numbers of Harrell, Bradford, McCoy, Reesing or Daniel, but he ranks third in the conference in passing efficiency, completing 69.4 percent of his throws for 1,687 yards and 15 touchdowns with just four interceptions.

Robinson’s 274 rushing yards rank fourth among Big 12 quarterbacks, and, with Kendall Hunter — easily the league’s leading rusher with 1,116 yards this fall — in the backfield with him, he simply hasn’t had to throw as much as some of his contemporaries.