Did free-agent spending pay off?

Everyone agrees NFL championships aren't bought in free agency, but there is an interesting twist to the start of the 2013 season.

The three top-spending teams in unrestricted free agency -- Miami, Indianapolis and Tennessee -- are a combined 7-2. How they'll do the rest of the season is uncertain, but perhaps volume buying is paying dividends early.

The more I study rosters in tight cap years, the more problems I see with depth. The middle class of veterans is going dry because more teams are going with minimum-salary young players. One or two injuries at a position can bring a team crashing into mediocrity or worse.

Something can be said, though, for taking advantage of extra cap room and trying to improve rosters. The Miami Dolphins, for example, weren't a bad team last year. They were 7-9 with a good defense, a promising young quarterback (Ryan Tannehill) and a good coaching staff.

General manager Jeff Ireland wagered $146.1 million of contracts on four players and also picked up veterans such as right tackle Tyson Clabo. The combination of Tannehill throwing to Mike Wallace and Brandon Gibson and more speed on defense should have turned the Dolphins from a seven-win team into a nine-win team.

But who would have thought the Dolphins would be heading to New Orleans for a Monday night game with a chance to go 4-0?

The Colts not only spent $132 million on eight unrestricted free agents, they traded a No. 1 pick next year to acquire halfback Trent Richardson. Those moves helped them survive the loss of three starters on offense since the start of the season. They also pulled off an upset victory over the San Francisco 49ers.

The Tennessee Titans invested $97.3 million in 10 players in unrestricted free agency, and they are only a Matt Schaub fourth-quarter comeback away from being 3-0.

The most puzzling issue early on is the surprise start of the AFC, which has won 11 of the first 14 games against the NFC. The NFC went 39-25 against the AFC last year and, on paper, appeared to be the better conference. Four of the five top-spending teams in free agency were in the AFC and have combined for a 3-0 record against the NFC.

Spending as these teams did in a tight cap environment might be a once-every-four-years venture, but it may help explain the surprising start of the season.

Here are the 10 trends for NFL Week 4.

1. Chance for redemption for the NFC East: Going into the season, the NFC East thought it would pad its win total going against the non-Denver teams in the AFC West, thought to be the worst division in football. Including the New York Giants' loss to Denver, the NFC East is 0-5 against the AFC West. This week it has four games against the division, all on the road. If the NFC East teams can't take advantage of these games, the division could be won by a team with an 8-8 or 7-9 record. One thing we know about the NFC East is that parity usually rules. Each team has enough confidence to go into rival cities and win road games, which often leads to 3-3 division records. To make up the difference, NFC East teams need to go 3-1 against other divisions. That won't happen if the East blows it this Sunday. If the Giants lose to the Kansas City Chiefs, they would be 0-4 overall and 0-2 against the AFC West. The Eagles, who have lost to the Chargers and Chiefs, face the impossible task of putting up their suspect defense against Peyton Manning. The 2-1 Dallas Cowboys have a chance to run away with the division, but that won't happen if they lose in San Diego on Sunday. And if the Washington Redskins lose to an understaffed Oakland Raiders team, they really are doomed to a bad season.

2. End of the Josh Freeman era: It's hard to tell which quarterback dropped faster, Mark Sanchez or Freeman. At least Sanchez had the thrills of going to two conference championship games in his first two seasons. Against an easy schedule in 2010, Freeman threw 25 touchdown passes and led the Bucs to 10 wins. Since then, his game has dropped off, and he was completing only 45 percent of his passes this season. Enter Mike Glennon, drafted as a candidate to be the quarterback of the future. Coach Greg Schiano decided to start Glennon this week to provide a spark and in a bid to end the team's three-game losing streak. The timing might not be great. Wide receivers Vincent Jackson and Mike Williams are hurt. The team plays as though it doesn't have a lot of confidence. The Arizona Cardinals come to town after losing three linebackers for the season in the past week. That might help Glennon, but is he ready? Glennon was dreadful in the preseason, completing 47.1 percent of his passes. He was even worse in the final preseason game, completing 7 of 17 passes for 63 yards. A negative spark could burn the Bucs even more.

3. In like Flynn? A concussion to Terrelle Pryor could give Matt Flynn the chance to play he's been seeking for six years Sunday when the Raiders play a desperate Washington team. After getting only two starts behind Aaron Rodgers in Green Bay, Flynn signed for $6.5 million a year in Seattle last year and then lost the starting job to Russell Wilson. The Seahawks traded him to Oakland, and he lost the starting job to Pryor. Even though Flynn knows he was traded to a team lacking in pass-catching talent, he was happy to get a chance. Repeating last year's bad preseason experience, Flynn developed elbow tendinitis in the middle of camp and needed rest. That gave Pryor enough chance to clinch the job. Pryor showed some promise, which means Flynn might play only until Pryor clears the concussion test. At least it will give Flynn some tape to show his next team. Because Pryor is a running quarterback, Flynn will be only a sideline call away from getting back on the field as this season goes on. For next year, who knows? Flynn was able to get paid once, but now he's battling to see if he has a future in this league.

4. Adjusting the body clocks: Pete Carroll inherited the Seattle Seahawks' long history of failure in early starts in the Eastern and Central time zones. The Seahawks play four more early games this season, three against playoff teams from last year. They face Houston on Sunday and travel to Indianapolis next week. Carroll addressed the situation by holding most training camp practices at 10 a.m. Body clocks might be not the problem this week. Blocking will be. The Seahawks' offensive line has to contain Texans defensive end J.J. Watt without left tackle Russell Okung, who is on the eight-game injured list. Paul McQuistan moved from guard to left tackle and might need the help of a tight end to slow down Watt. To make matters worse, center Max Unger missed practice time this week with an arm injury. Right tackle Breno Giacomini could miss the game because of a knee injury. The Texans, meanwhile, are trying to repair bad habits developed during their first three games. Somewhere in the second and third quarters, both sides of the ball have gone into funks, forcing fourth-quarter comebacks. They are 2-1 in those situations, but Gary Kubiak is looking for more of a 60-minute effort.

5. Can the Patriots win a shootout? Down his top five pass-catchers from last year, Tom Brady made the best of a bad situation during the first three games. The Pats have gone 3-0 but are averaging only 19.7 points a game. And this was done in what was considered the easy part of their schedule, games against the Bills, Jets and Bucs. Sunday night, Brady & Co. get a tougher test. They play an Atlanta Falcons team that is averaging 23.7 points a game and can outscore most teams. The Falcons have their own problems. They lost five starters to injury in Week 2, and that left them hurting in last Sunday's loss to the Dolphins. With the Falcons lacking a dominating defense, Matt Ryan will be asked to carry the team on his strong right arm against the Patriots. If the Falcons score touchdowns and the Patriots settle for field goals, Brady could suffer his first loss of the season.

6. London didn't expect two winless teams: The NFL thought it had the perfect matchup for its first of two games overseas. The Pittsburgh Steelers have one of the best brands in sports and an owner, Dan Rooney, who spent two seasons as the U.S. ambassador to Ireland. The Minnesota Vikings made the playoffs last year. Both teams enter Sunday's game with 0-3 records, and the loser can probably forget about making the playoffs. Plenty has gone wrong for the Steelers. Their offensive line is a mess. Ben Roethlisberger has struggled to compensate for the lack of big plays on defense and the running game. For the Vikings, the blame for the poor start keeps going to quarterback Christian Ponder. His situation is becoming more and more like Freeman's in Tampa Bay, except that Ponder won't be a free agent after the season. It's not out of the question that the team could soon elevate Matt Cassel. The Vikings have a bye after this game, and that's when quarterback changes often occur. The Vikings might be pondering change.

7. Key test for Lions: If the Detroit Lions are going to be contenders in the NFC North, Sunday is a must-win game. The Lions host the Chicago Bears, and no serious contender can afford to lose a home game in divisional play. A loss would drop the Lions two games behind the Bears, who would improve to 4-0 with a victory. What the Lions can't afford to do is lose because of their mistakes. Everyone knows they tend to commit a lot of dumb penalties, and the Bears are one of the most opportunistic teams in football. Since 2009, the Bears have forced a league-high 93 turnovers. Reggie Bush is expected to be back for the Lions after missing a game because of a knee injury. It will be important for him and QB Matthew Stafford to avoid turnovers. Regardless, this should be an entertaining, potentially high-scoring game.

8. Injury concerns abound: A lot of teams appear to have more serious injury concerns than usual for this stage of the season. As noted above, the Seahawks could be down three starters along their offensive line. The Chargers' entire starting offensive line is on the injury list. San Diego hosts the Cowboys, but Philip Rivers could be in a tough spot if three or four starters can't suit up Sunday. Arizona lost two starting outside linebackers and backup Alex Okafor. Can the Cardinals generate any kind of a pass rush against the Buccaneers?

9. Other divisional games: The Cleveland Browns shocked the NFL with their victory in Minnesota last Sunday with Brian Hoyer behind center. The Browns know this week they can't sneak up on anyone. Willis McGahee is taking over at starting running back for Cleveland, but the Cincinnati Bengals will concentrate on stopping the Browns' passing attack. Injuries in the secondary could be a problem, but the Bengals have the talent to outscore Cleveland. Indianapolis shouldn't have any problems with Jacksonville. Like the Seahawks did last week, the Colts could use this game to experiment with things on offense and defense. The Jaguars are 0-3 and have been outscored 92-28.

10. The ground-and-pound Titans? Some have compared Jake Locker to Mark Sanchez in Sanchez's early days with the Jets. What is certain is Titans coach Mike Munchak is trying out Rex Ryan's formula for success. The Titans are more aggressive on defense, and Munchak is stressing the ground-and-pound approach on offense, trying to win games with a power running game. That won't be easy against the 2-1 Jets, who have played well on defense.