The trade that sent Chris Chambers to San Diego has elicited plenty of reaction.
For the Chargers -- a franchise that builds through to the draft -- to surrender a second-round choice was a big sacrifice, but it was a shrewd move. San Diego acquired a 29-year-old Pro Bowl-caliber receiver who had three years remaining on his contract.
The Chargers are aware they have a window of opportunity to win a championship. They went 12-4 in 2004 and 14-2 in 2006, but didn't win a playoff game in either season. As a result, Marty Schottenheimer was replaced by Norv Turner
With the addition of Chambers, the Chargers now have 35 players -- including most of their starters -- signed through 2009. From now until then, they figure to be a Super Bowl contender. After that, they will be forced to regroup and re-evaluate.
Accurately determining a championship window can be difficult in the salary cap era. Injuries, free-agency defections and other factors can be tough to predict, but if a team is put together well, it can stay at a top level for six or seven years.
So how do the Patriots and Colts defy the odds?
Chris Chambers
Wide Receiver
San Diego Chargers
The window for both teams began in 2000. For the Patriots, it was the hiring of Bill Belichick. It took him a year to sort through the salary cap and roster problems, and he had them winning a Super Bowl in 2001. They have since added two more Super Bowl rings.
The Colts started their run in Peyton Manning's second season. They are poised to reach the postseason for the seventh time in eight years and are looking to repeat as Super Bowl champions.
Amazingly, the Patriots and Colts are getting better at a time when they should be on the decline. Led by Tom Brady, 30, New England's offense is on pace to break numerous NFL records. Manning is only getting better with age. At 31, he has a chance to eventually break many of Brett Favre's records.
A Hall of Fame quarterback enables a franchise to extend its championship window. Favre proved that with the Packers. When Mike Holmgren left for the Seahawks, Mike Sherman and the front office revamped the roster, keeping the Packers as a playoff threat through 2004. As long as a team has a top quarterback, it has the ability to bounce back in the salary cap era.
The days of winning without a top quarterback are gone. A strong defense and a good running attack can get you to the playoffs, but a great quarterback is needed to win the Super Bowl ring.
Brady and Manning aren't slowing down. With the right supporting cast, both have the potential to extend the championship run of their franchises.
The Chargers knew this when they made the Chambers trade. Last year, San Diego won 14 games in the regular season, but lost a playoff game to New England, with Brady engineering a big comeback in the fourth quarter.
The following week, Manning overcame a 21-6 second-half deficit to beat the Patriots in the AFC title game. The bottom line is against these two quarterbacks, you can never score enough points to feel comfortable.
If the Chargers plan to compete against the Colts and Pats for the next three years, they need to be great on offense and acquiring a Pro Bowl wide receiver is a step in the right direction.
The Chargers believe they have a quarterback in Philip Rivers who can compete at a Pro Bowl level. Chambers can grow with Antonio Gates, LaDainian Tomlinson and Rivers from now until 2009. Their window is set. The tough part is the Colts and Patriots have bigger windows.
John Clayton, a member of the Pro Football Hall of Fame writers' wing, is a senior writer for ESPN.com.