Originally Posted by Caveat Emperor
I would imagine that, with Stubbs' fantastic speed, he cheats back a bit to have a play on the hard-hit balls that head towards the wall and trusts his own footspeed to make up the extra step or three on the softer / looping stuff.
Could also be defensive strategy -- concede a few more singles (and a few more balls to the 2nd basemen and SS moving backwards) to protect against the XBHs off the walls and into the gap. With the plus-defending Phillips @ 2nd, I suppose you can figure that he'll get at least some of the "can't make it in" CF balls. Additionally, if the idea is that Stubbs has extra responsibilities to his right side (given Gomes' defensive adventures), it would make sense that he pay a little further back.
Usually a very fast CFer will play shallow because he knows he can go back and catch up to the ball. Perhaps Stubbs has trouble going back on the ball. I've seen a couple - like the one last night - bounce off his glove while he was going back for the ball. Granted, they were hard hit balls and few CFers could even lay a glove on the ball but that's the only reason I can think of - besides yours- why he plays back that far.