The once bulletproof façade of Bill Belichick’s invincibility as a coach has taken some hits over the last several years, and the Patriots’ 21-17 loss to the New York Giants in Super Bowl XLVI was another shot across the bow at Belichick’s sterling reputation.

I half-jokingly like to point out that New England hasn’t won a championship since they were caught in the Spygate scandal several years ago. But now, it’s impossible to look at Belichick’s resume and not recognize that fact. The Patriots were known to have recorded opponent’s defensive signals through the 2006 season. In two of his team’s Super Bowl wins, quarterback Tom Brady had access to the other team’s signals during end-of-half and end-of-game no-huddle drives; against the Rams in Super Bowl XXXVI and the Panthers in Super Bowl XXXVIII. In each of those games, the Patriots had a touchdown drive that ended in the final minute of the first half (a five-play, 40-yard, 49-second drive that culminated in a Brady pass to David Patten with 31 seconds left in the second quarter vs. the Rams, and a six-play, 78-yard, 49-second drive in which Brady hit David Givens for the touchdown vs. Carolina with 18 seconds left in the half). Then, Brady conducted drives to winning field goals at the end of the fourth quarter in each win. Brady and the Patriots also had a touchdown drive late in the first half against Philadelphia in Super Bowl XXXIX.

In their defense, the Patriots have done that a lot since Spygate, too. However, when Brady took over against the Giants with 57 seconds left, the magic wasn’t there this time.

Since winning their first Super Bowl against the Rams 10 years ago, the Patriots have lost to a team twice in a season on four occasions, and all four second losses have come in the playoffs. In 2005, they lost their playoff opener to Denver, whom they had lost to earlier in the season. The same thing happened in 2006, when the Colts beat the Patriots for the second time that year in the AFC Championship Game. Last year, the Jets eliminated New England from the playoffs with their second win over Belichick’s team that season. And this year’s Giants knocked off the Patriots in Week 9 and then again in the Super Bowl.

I picked the Patriots in this game because I thought Belichick and his staff would have learned so much from the first game. But even with two Giants tight ends out of the game, New York was able to take advantage of the weakness of New England’s defense. What must be alarming for Patriots fans, aside from their leaky defense over the last couple of years, is the team’s inability to maintain their offensive excellence in the playoffs. Much like the Greatest Show on Turf Rams, once New England gets to the playoffs, their offense dries up. A team that has averaged more than 30 points a game for much of the last five years has scored, in their last seven playoff games, 21, 14, 14, 21, 45, 23 and 17 points. The Pats are 4-3 in those games, and have been stymied by the Giants in the Super Bowl with four touchdowns in two games.

New England should be commended for their sustained run of excellence. What would we give here in St. Louis to have two Super Bowl appearances and four playoff years in the last five? But in terms of legacy, Belichick is taking a hit. With the losses of assistant coaches like Charlie Weis, Romeo Crennel, Eric Mangini, Josh McDaniels, Dean Pees, Dom Capers and Brian Daboll, the staff has dealt with tremendous turnover in the last half-dozen years. In addition, key personnel guys Scott Pioli and Thomas Dimitroff have left to become general managers, in Kansas City and Atlanta, respectively. While continuing to succeed in the regular season, how much effect did those guys have on Belichick’s post-season success? Much is made of the fact that Bill Parcells never won a Super Bowl without Belichick. Well, Belichick has never won one without Weis and Crennel.

Even with all that turnover, the Patriots still went 13-3 this season, and then knocked off Denver and Baltimore in the playoffs. But they lost to the only two teams they played with winning records in the regular season, Pittsburgh and the Giants. After beating 8-8 Denver in the first round, they did beat the Ravens in the AFC Championship Game. So New England went 1-3 in the four games they played against teams with winning records in the 2011 season.

I give all the credit in the world to Tom Coughlin and his Giants staff. They’ve developed Eli Manning, their offensive line had tremendous turnover, but turned into a solid group, and they turned Hakeem Nicks and Victor Cruz into star receivers. Coughlin has been able to keep offensive coordinator Kevin Gilbride and most of the offensive staff together, and has done a great job of finding defensive coordinators Steve Spagnuolo and Perry Fewell. Coughlin and his staff did a fantastic job this year. In the playoffs, the Giants beat 10-6 Atlanta in the first round of the playoffs, and then went on the road to beat 15-1 Green Bay and 13-3 San Francisco before beating New England. Their greatness is undisputed.

My only question is this: is beating the Patriots such a big deal anymore?