You know the story. Manning sucks in the playoffs. He chokes away games. He can't win. He forces it too much in playoff games and costs his team the game.
I decided to look at his QB ratings in playoff games, both wins and losses, and see if there was any pattern.
Playoff QB Rating: 84.81
Not bad. Not up to his regular season standard but still a solid QB Rating. Nothing to be too ashamed of.
Playoff Win QB Rating: 117.18
WOW! Now that's what I'm talking about. in five wins Manning has an overall QB Rating of over 117. He obviously plays well (on the average) in wins. In fact, the two wins this year are his first playoff wins with QB Ratings under 138.75.
Playoff Loss QB Rating: 61.62
Hmmm this seems to give creedance to the "he chokes away games" accusation. But does it?
But what do the playoff losses have in common?
Average Points Allowed in Playoff Wins: 15.8/game
Average Points Allowed in Playoff Losses: 21.14/game
So in the games where Manning struggles, the defense has also allowed an average of 5.34 points more a game.
I would argue that when the defense struggles, Manning takes it upon himself to try and carry the team on his back alone and win the game himself by passing more. Do the numbers bear this out?
Pass Attempts in Playoff Wins: 31.4/game
Pass Attempts in Playoff Losses: 36.5/game
Hmmm... so in games where the D is giving up more points, Manning passes more. This is conjecture (and I'd have to watch all the games an analyze them to know for sure) but it seems to me that this shows that Manning forces it and tries to do too much when he has to make up for a poor defense. When he has a defense backing him up he's looser and more able to play his game at an exceptional level.
The argument can be made that he needs to not force his game so much, that he needs to play within himself and in his normal loose high level even when the other team is scoring. But for people to say that Manning single-handedly chokes away playoff games is wrong. The only criticism that can be reasonably made is that he plays outside himself when the defense is playing poorly and already losing the game for the team.
These last two games are certainly exceptions to the rule. He has been able to play poorly but he's had stellar defensive efforts behind him (and played a couple tough defenses that have been geared towards taking and keeping him off the field and defending the deep ball).
The worst of the last two games, with the 39.58 QB rating, was also tied for the third fewest pass attempts for Manning in a playoff game. This would tie into the argument that with the defense playing well he didn't need to take the game on himself - and with it playing at such an amazing level he was free to just go for some big chances and the offense didn't need to rely as much on the pass at all. (For the KC game he was rated 71.93, 10 above his loss average but a below average game for his playoff career)
This is admittedly using averages (not the best number to look at statistically) but I think it definitely shows that the shallow analysis by commentators and Patriots fans leaves alot to be desired.
Box Scores from http://www.jt-sw.com/football/boxes/index.nsf
QB Rating calculated at http://www.primecomputing.com/