The hot stat in baseball is replacement value. It’s expressed in different ways, including WAR, or “wins above replacement,” but its basic premise is this: if you replaced player X on your team with a statistically average player, would he perform better or worse than the player he replaced – and by extension, would the team be better or worse?
Yes, to the extent that his replacement value is higher. You may want Brady over Manning in a big game, and that’s your right. Replacement value doesn’t go there.
All of which is the long way ‘round to the big question: What player is/was the most indispensable to his team?
The simplest way to look at this is to examine the change in record from the year before the player left to the year he left, and then if he went to a new team the difference between the year before the player came and the year he came. A couple of simple change equations, acknowledging that the loss of one player does not define any team’s season.
Let’s work with the top 50 players of all time according to Pro Football Reference, and let’s look at changes that occurred in the meat of that player’s career, if that’s possible.
Lest you think the transition from Brett Favre to Aaron Rodgers was smooth and productive, guess again. The Packers got more than 50 percent worse; the Jets got 125 percent better. And the QB aside, the Favre-led team was nearly indistinguishable from the Rodgers-led team; it wasn’t like the defense collapsed or the offense was gutted by injuries. Favre at that stage of his career was that much better than Rodgers at that stage of his career. It was a big difference.
This is good, but there's still the Peyton Manning situation to consider. And we will ... next time.
And I promise there will be a next time.