An interesting post from Dan Szymborski of Baseball Think Factory renown over at ESPN:
What would this AL East race look like if the Sox had stayed healthy?
….For those five starters, there were a combined 996 missed plate appearances compared to what would be expected.
Those 996 plate appearances had to go somewhere, so to do the next phase of this projection, I had to take them back from the guys who got them. I tried to be as fair as I could — Daniel Nava and Ryan Kalish lost the most, as did players like Bill Hall.
Then I used runs created, a Bill James stat. I created an estimate of how many runs the replacements created in those 996 plate appearances — and how many the injured players would have likely created. For the injured players, I used their preseason ZiPS projections as a guide to how they likely would have played, given their normal playing time.
The five injured starters would have created 153 runs; the replacements created 114. That’s a difference of 39 runs, which equates to roughly four wins.
If you look at the AL East standings, that makes the Red Sox a 78-53 team as opposed to their current status as a 74-57 team; they’d be three games back of the New York Yankees and Tampa Bay Rays, as opposed to their current seven games back.
I did not want to reproduce the entire article, and was forced to snip out some of the analysis. I highly recommend reading the original article to make sure you capture the context of his calculations.
Dan’s conclusion seems about right. One thing that the saber revolution has taught us is that even the greatest players tend to be worth only 6-7 wins more than a replacement player over a full season. This does not mean that the player only contributes to 6-7 victories. Rather, it states that all of the player’s contributions add up to 6 or 7 full victories that can be credited to the player (relative to a replacement player baseline). Being that none of the Sox players missed the entire season and that their replacements played above “replacement level,” it seems logical that the injuries cost the Sox fewer wins than you might think if you were, say, an overnight host for WEEI (who stated that the Red Sox lost 10+ games in the standings due to injuries and would be way out in front without them). The injuries have killed Boston, and they would absolutely be more involved in the race if they had remained healthy. But they would likely still be on the outside looking in at the start of September even without their incredible spate of injuries.