Colt McCoy remembers the Year of the Quarterback in the Big 12 last season. It’s no mystery to him why the league’s offenses haven’t been able to keep up the blistering scoring pace this year.

“Graham and Chase graduated and Sam got hurt,” McCoy said, outlining the star quarterbacks lost from last season’s record run of scoring.

Texas Tech’s Graham Harrell and Missouri’s Chase Daniel finished their careers as the most productive players in terms of total offense in the 14 seasons of the Big 12. Oklahoma’s Sam Bradford took home the Heisman Trophy after throwing for 50 touchdowns last season and he missed most of this year with a shoulder injury.

With only McCoy back from the foursome that placed among the top five vote-getters in the Heisman balloting — Bradford, McCoy, Harrell and Tech receiver Michael Crabtree — the shootouts are kind of back to normal in the Big 12.

“Every year is going to be different. It’s not normal to have a year like last year,” said McCoy, whose Longhorns rank second in the nation in scoring. “I think we had four or five guys we were talking about the Heisman every week, all in the Big 12. That’s rare in any conference.”

After last season, when teams scored a Big 12-record 35.6 points per game, production is down by 6.2 points per team per game this year.

Nine of the league’s 12 teams have seen their scoring averages fall, and eight of those have dipped by at least 4 points.

No team has had a bigger drop-off than Oklahoma, which set an NCAA record with 716 points last season and has seen its scoring average go down by 17.8 points per game. The Sooners lost not only Bradford but tight end Jermaine Gresham, a second-team All-American who’s second in school history with 26 touchdown catches, to injuries while four offensive linemen and three top receivers moved on.

The no-huddle offense that averaged 51.1 points last season has been bogged down by poor execution by inexperienced players.

“Last year, you had some more talented players playing. With Bradford and Gresham and those guys, you’re probably — in our world — scoring a few more points,” offensive coordinator Kevin Wilson said.

“With graduation, we lost some good guys. I’m sure that’s a little bit a part of it. … Other than turnovers, I think our lack of production has been with the increased number of penalties we seem to have that get us in first-and-20 and 15 more than I remember in years past.”

Missouri and Kansas State have also seen their production slow by double digits after losing star quarterbacks. The Tigers are scoring 13.3 fewer points per game without Daniel and 2008 Biletnikoff Award finalist Jeremy Maclin, while K-State is off last year’s pace by 10.1 points per game without first-round NFL draft pick Josh Freeman.

Nebraska (9.2), Oklahoma State (7.7) and Texas Tech (5.9) are also scoring about a touchdown less per game.

Missouri coach Gary Pinkel also suggested that defenses are adapting to stop spread offenses since they are so common now. Oklahoma State coach Mike Gundy agreed.

“Throughout the country, I think defenses are starting to catch up with what offenses had (after) a pretty good run for four or five years,” Gundy said. “Last year was somewhat different because there was tremendous quarterback play in this league, and there’s still good quarterback play — but there was tremendous quarterback play in this league.

“If you follow the game really close, you’ll see that teams that are having success and winning games — in most cases — have good quarterbacks that have experience and can make plays.”

Kansas coach Mark Mangino, whose Jayhawks are scoring 4 fewer points per game through some struggles by quarterback Todd Reesing, said he started noticing adjustments to the spread midway through last season.

“More and more teams in our conference are slowly but surely fading out of the spread offense,” said Mangino, who brought the spread to Kansas from Oklahoma just as Mike Leach took it to Texas Tech.

“I think it goes back to the old adage that coaches want to run the ball, control the clock and play great defense. What did Woody Hayes say? ‘When you throw the ball, a lot of bad things can happen.”‘

The only Big 12 teams to buck the trend are A&M, Baylor and Colorado. The Aggies have easily the biggest improvement, scoring 8 points more per game. The Bears and Buffaloes are less than 2 points over their 2008 average, despite Baylor losing quarterback Robert Griffin III for the season and Colorado switching between Tyler Hansen and Cody Hawkins.

Both still rank in the bottom third of the league in scoring.

“I won’t be surprised if in a year or two a couple teams pull out the wishbone, and I’m not saying that jokingly, either,” Mangino said.