In the thirteen seasons with Bill Belichick and Tom Brady, the New England Patriots have earned:
12 Division Titles
11 Divisional Playoff Rounds
9 Conference Title Games
6 Super Bowl Appearances
4 Super Bowl Titles
Over the past twelve seasons, including the Matt Cassel year, the Patriots have hit the 10-victory benchmark each time, the second longest 10-win streak in NFL history. There are six other teams with multiple-season streaks of 10+ victories and none of them have more than three in a row. New England is in the midst of a twelve-year streak.
The 83-98 San Francisco 49ers strung together 16 straight seasons of 10+ victories, spanning two Hall of Fame quarterbacks in Joe Montana and Steve Young. A strike-shortened 3-6 1982 season separates an additional Super Bowl victory 1981 season from that streak.
If we include those two seasons, for a total of eighteen, the 49ers earned the following accolades:
13 Division Titles
14 Divisional Playoff Rounds
10 Conference Title Games
5 Super Bowl Appearances
5 Super Bowl Titles
Since the Cassel year and the Strike Season both don't affect these playoff standings, it's a pretty straight forward comparison. New England has four seasons to earn one Division Title, reach three Divisional Playoff Rounds, get to one more Conference Title Game, and win one more Super Bowl to match the 49ers streak of success.
New England could already compare themselves to the lengthiest dynasty in football history, all while doing it with a salary cap.
The Patriots are also coming off a streak that the 49ers never achieved: four straight conference championship games. New England became the seventh team to reach four straight and the second to do it in the salary cap era. The first team to make four straight in the Super Bowl Era might be able to make a claim for one of the greatest dynasties in football history.
The Oakland Raiders reached four straight confernce title games from 1967 to 1970, including an appearance in 1967's Super Bowl II. After an 8-4-2 season in 1971 where they missed the playoffs and a 10-3-1 season in 1971 that resulted in a Divisional Round loss, the Raiders went to five straight conference title games from 1973 to 1977, including a Super Bowl victory in 1976.
To restate, the Raiders reached nine conference championships in eleven seasons.
Over that time span, the Dallas Cowboys reached four straight conference titles from 1970 to 1973, including a Super Bowl loss in 1970 and a Super Bowl victory in 1971. This could have been considered the most successful consecutive run until the 1992-1995 Cowboys reached four straight conference title games along with three Super Bowl victories.
Two of those Super Bowl victories came against the Buffalo Bills, who were in the midst of one of the most brutal stretches in sports history. The Bills didn't just reach four straight conference title games, they reached four straight Super Bowls from 1990 to 1993, losing all of them.
All three of these teams and all five of these streaks happened before or during the implementation of the salary cap.
The 2001-2004 Eagles were the first team in the salary cap era to reach four straight conference title games, losing the first three, before making it over the hump and losing to the Patriots in the 2004 Super Bowl.
The 2011-2014 Patriots have reached four straight conference title games and have collected a Super Bowl win and loss along the way. It's not as noteoworthy as their three Super Bowl titles in four seasons at the start of the era, but it's not far behind in degrees of difficulty.
If the Patriots can reach another conference title game in 2015, they will be the second team, and first since the 73-77 Raiders, to reach five straight. New England is already in the middle of the best run of the salary cap era; with another year at the top of the league, they could have a claim to the best run in the history of football.