Defenses have bounced back from the NFL's efforts to get more offense into the game.
Enforcement of illegal contact after 5 yards opened up offense in 2004, with points per game increasing from 41.7 in 2003 to 42.97 in 2004. Total yards per game for both teams increased from 637 in 2003 to 654 in 2004. It was also a record-setting year, with Peyton Manning taking advantage of the new freedom for his wide receivers to toss 49 touchdown passes.
As is the way in the NFL, defensive coordinators find ways to adjust. Some coordinators went to the complexities of the 3-4, which gives them the ability to blitz from any spot in the defense. Blitzes are up. Numbers are down. Offensive numbers are back to just about where they were before the changes -- 638.5 total yards per game and 41.8 points per game.
But there is one offensive trend that seems to be dominating 2005: execution over trickery. Look at the successful offenses and you will see different styles but similar philosophies. The Colts are unbeaten because of their endless attention to detail, the demanding execution of Manning and the direction of offensive coordinator Tom Moore. Mike Holmgren has the league's No. 1 offense because he simply runs his pure form of the West Coast offense. The Broncos have the AFC's second seed because Mike Shanahan directs his highly orchestrated running offense.
Simplicity through execution. It's probably the way life should be in the NFL. Annually, critics look at the offensive numbers and demand changes. The league's best offenses of 2005 are the result of patience and discipline. In many ways, it should be a lesson to those teams constantly juggling parts in an effort to find the right combination in the hopes of getting some scoring.
Just about every top offense has been together for some time. The NFL still is a league of haves and have-nots based on the play of the teams' quarterbacks. The haves have winning records and are scoring more than 20 points a game. The have-nots have losing records and score in the teens. That's the NFL in 2005.
The lesson should be that offenses don't succeed with trickery alone. Talent is one thing. You can't succeed offensively without talent. But constant change doesn't work either. The Lions will find that out as the organization fumbles around looking for new coaches and a new direction.
It's easy to cite the success of the Colts. Manning is a once-in-a-lifetime franchise quarterback. He has had years to work his timing with some of the most talented, skilled players in football -- Edgerrin James, Marvin Harrison, Reggie Wayne, Brandon Stokley, Dallas Clark and others.
But the beauty of the Colts' actions is the simplicity. They run everything out of no-huddle, which keeps their offense simple and focused. Manning's a perfectionist, which makes him great. They spend hundreds upon hundreds of hours during the offseason working on the execution of their plays just to get things right.
"I think people are always going to look at us as a finesse team because we do move things around," Colts coach Tony Dungy said. "We try to run when you're thinking pass. We pass when you're thinking run."
All the different scenarios have been worked on so many times that Manning's teammates are an extension of him. They can read each other's minds during plays. Because of that, the Colts have taken offensive execution to an unprecedented level. They've had 38 touchdown drives and 15 field goals in 110 offensive possessions. They are a machine that's going to score 30 points a game and do it in 10 possessions.
But 31 teams don't have Peyton Manning. The 9-2 success of the Broncos this season is a tribute to the simplicity and execution of Shanahan's system. After two wild-card playoff seasons that ended up being ruined by blowout losses to the Colts, Shanahan didn't panic and is now being rewarded. Critics in Denver wanted to run Jake Plummer out of town.
But Shanahan stood behind Plummer and made this team better on offense by stressing execution. Plummer always had the tendency to gamble and throw an interception at the worst time. Shanahan had similar problems with Brian Griese, but there was something about Plummer that gave him more staying power. Griese was a 60-plus percent thrower but a 50 percent winner. Plummer was a winner. Jake the Snake has the knack for rallying his offense and making plays with his feet or his arm.
Instead of ripping apart the offense this year, Shanahan worked on execution. His running game is like ballet. Linemen make coordinated moves and hit defenders from all different angles. It's a thing of beauty to watch, and it has allowed him to trade running backs for defenders (Clinton Portis to the Redskins for Champ Bailey and Reuben Droughns to the Browns for Michael Myers and Ebenezer Ekuban) and plug any back into the offense. For Plummer, Shanahan took away his quarterback's bad habit of throwing interceptions by trying to limit him to 26 or fewer passes per game.
"They have a philosophy, and they don't run a lot of plays," Cowboys coach Bill Parcells told the Dallas media before his team's Thanksgiving game against the Broncos. "They put it in place and they integrate a lot of players into it, and they do a very good job with it."
Shanahan didn't blow up the offense to vent his frustration at losing in the first round of the playoffs. He stayed with Ashley Lelie as the team's second receiving option next to dependable Rod Smith even though Lelie tended to drop some passes. Shanahan focused on letting Lelie run his best deep routes, and he worked with Plummer on getting a few balls to him per game.
Perhaps one of the most fun stories in the league still slipping below the radar is Holmgren in Seattle. Holmgren has been calling plays probably longer than any other coach in the league. He did it back in the old 49ers days. He won a Super Bowl with Brett Favre in Green Bay.
The Seahawks' current No. 1 ranking on offense is a testament to the coach's dogged, stubborn philosophies and the underrated skills of Matt Hasselbeck as a quarterback. To think the Seahawks could rank No. 1 in offense with 386.1 yards a game without their top two receivers from last year -- Darrell Jackson and Koren Robinson -- is remarkable. Jackson has missed most of the season with a knee injury. Robinson had alcohol problems and is making a comeback in Minnesota.
Holmgren just asks the next-best backup to step up and keeps running his offense. He's having more fun than he has had in years. He's having more fun than he has had in years. His is the true version of the West Coast offense, the one Bill Walsh taught him. It features no shotgun. It stresses the three-receiver principles, but Holmgren occasionally will slip in a four-receiver set here or there. Even though Shaun Alexander is the league's leading rusher, Holmgren still uses the pass to set up the run, just like Walsh.
It has worked this year because of the execution. Losing Jackson and Robinson has created problems in the offense. Bobby Engram and Joe Jurevicius aren't speedsters. Cornerbacks try to squat on routes to free up an extra defender to stop Alexander. But Engram and Jurevicius are sure-handed. They don't drop passes.
So, Holmgren runs his offense. Hasselbeck jokes that Holmgren is actually unpredictable because he will run plays he likes regardless of the defense. Maybe he liked a play that worked a year ago against the 49ers. Holmgren will call it again this year even though the 49ers have switched from a 4-3 to a 3-4.
Good execution will make the play work. Most of the good offenses this year are like that. They have the stability of years together with either the quarterback working with the receivers or the offensive line working with the running back.
That's the lesson the Detroit Lions should learn. They've fired two coaches trying to develop Joey Harrington. They surrounded him with three first-round receivers who aren't necessary followers, and all they've experienced is instability.
Shanahan could have bailed on Plummer when he was struggling. He didn't. Holmgren stayed with Hasselbeck through some periods of struggles. He has profited.
The great offensive successes of 2005 are a tribute to smart coaches and great execution.
John Clayton is a senior writer for ESPN.com.