By Nate Dunlevy
Cold, Hard Football Facts resident gleeful Colts fan
There was just 2:30 to play in the 2006 AFC title game, and all New England needed were 4 yards.
Four yards on third down would put the Patriots back in the Super Bowl for the fourth time in just six seasons. Overmatched Rex Grossman awaited in Miami.
But Tom Brady's pass to Troy Brown was just wide enough off the mark to allow Bob Sanders of the Colts to knife in and break it up. In what would become the dominant theme of the next four seasons, Bill Belichick's defense couldn't protect the precarious three-point lead, and the Colts, not the Patriots went to Super Bowl XLI.
Going into that game, the Patriots were 12-1 in the postseason during the Brady era. They had a tightly defined identity as a blue-collar defensive team with the perfect quarterback to coax just enough points out of the offense to win. 
Tom Brady was always given credit for his incredible playoff record. But the numbers, the Cold, Hard Football Facts, say he didn't deserve the praise. In nine of those 12 playoff wins, Brady threw for fewer than 250 yards. More importantly for our purposes, he averaged less than 6.5 YPA in eight of those 12 games. Brady produced as many playoff games with a rating below 80 (five) as he did above 100. In four of his five postseasons, Brady had played poorly at least once. But every time he played poorly, his defense bailed him out.
Somewhere along the way, after that landmark 2006 AFC title game, Belichick chose to reload and redefine the Patriots. He stocked up on wide receivers like Wes Welker and Randy Moss, and Tom Brady was challenged to take his game to another level. The results were astonishing. Long decried as a "system" quarterback, Tom Brady led an all out assault on the record books.  
His 2007 and 2010 seasons rank as two of the most spectacular passing efforts in history and netted him two MVP awards (assuming, as we all do, that he wins the award for the 2010 season). Brady saw his yards per attempt spike to 9.0 and beyond, as his passer rating twice soared above 110, a level few men had ever achieved. Nobody had done it twice.
Without question, Brady is a better quarter back today than he ever was when the Patriots were winning Super Bowls. He has improved in every aspect of playing the position. 
They don't call him a caretaker anymore.  
They don't call him a system quarterback anymore.
But they don't call him a champion anymore, either.
Belichick's gambit to remake the Patriots into an aerial offensive force produced spectacular regular season results, but has left New England high and dry in the playoffs. Since starting his career 12-1, Tom Brady's Patriots have lost four of six playoff games, including the last three straight.
Brady hasn't always played poorly. His rating has wavered mostly in the 80s. But the same performances that held up so well when supported by an elite defense were not nearly enough as that defense suddenly grew old, and then just as suddenly became too young.
New England's glory years support the belief that Brady did just enough to get bailed out by a great defense.
2001 playoffs – Tom Brady had brutal day in the snow against the Raiders, but when his touchdown run cut the Oakland lead to three with less than eight minutes to play, his defense forced two punts by an offense led by Pro Bowler and future MVP Rich Gannon, who was in the middle of a four year run of dominant quarterback play. 
2003 playoffs – Tom Brady posted a rating of 73.3 against the Titans, and but his field goal drive with four minutes left held up as his defense harassed Steve McNair, forcing the Titans into a grounding call and a holding call with under two minutes to play and the ball at the New England 33.
2003 playoffs – Tom Brady posted a rating of 76.1 against Indianapolis, but his defense stopped the Colts on four straight plays in the closing minutes to secure the win.
Things started to change when Brady's mediocre performances weren't enough to when paired with a defense that couldn't hold a lead:
2006 playoffs – Tom Brady posted a rating of 79.5 in Indianapolis, but went home a loser as his defense allowed an 80-yard touchdown drive to win the game in the final two minutes.  
2007 playoffs – Tom Brady was battered in the Super Bowl, but gave the Patriots a lead late in the fourth quarter, only to see his defense struggle to stop Eli Manning, who led to fourth-quarter touchdown drives.
2010 playoffs – Tom Brady struggled to read the Jets coverage, but got his team to within three points at the end of the third quarter.  His defense then allowed a 75-yard drive (all through the air) to a young quarterback (Mark Sanchez) with a career passer rating of 70.
Tom Brady is a better quarterback than he has ever been before. Hey may have been better this season than anyone ever. His team, however, is not nearly as good as they once were.
Tom Brady didn't carry the Patriots to three Super Bowl wins. He didn't carry them to another one this year, either. The only difference is that, this time, football fans expected him to deliver. But the truth is that he's just not up to the task.