Heisey is currently batting .284 vs. Stubbs's .221 - a difference of .063 (we'll come back to OBP). I know there are differences in sample size and situations of their AB's, but let's assume they are accurate representations of their respective abilities. Let's further assume that over the course of a week, an average player gets about 25 AB's (~4 per game * 6 games per week). Multiplying, that means Heisey should get an average of 1.6 extra hits per week - or to keep this in round terms, more than one, but less than two. So in order for Stubbs's defense to be worth more than Heisey's offense, doesn't that mean Stubbs just needs to get to two more balls during the course of the week than Heisey would?
I was a Heisey supporter going into this exercise, but two plays a week doesn't sound like that much - if Stubbs truly is a superior defender, he should be able to do that, right? And if you look at it using OBP (.321 vs. .286, a difference of 0.35), it falls to only one play a week (of course, that assumes a walk = a hit, which it doesn't).
To be sure, this simple analysis ignores a number of other factors such as throwing ability, slugging, strike outs vs. "productive" outs, etc. but on the face of it, I'm not sure the added offensive production is worth a big step down in defensive prowess. Of course, if Heisey's defense = Subbs's defense. . .
Does this way of looking at it make any sense, or is it way too simplistic? I'd be interested to hear your thoughts.