Those of us who watch on TV notice the benefit (or non-benefit) of the shift when the batter hits into an out (or avoids one because of the shift). But there's a bit of a chicken-chicken comparison too... How does the shift affect what the batter does? Mark Reynolds punched a single through the second base position last night... did he do it on purpose? It looked like it. The amusing thing about the shift, to me, is that it is designed to prevent singles. However, if it makes David Ortiz go for a single rather than a home run, there may be big gain that cannot be measured.

I watch almost all the Orioles games. Gary Thorne has reached the point where he states whether or not The Shift is on or off for almost every hitter, or at least it seems that way in retrospect. The Orioles are definitly using altered defensive alignments much more frequently than last year. My anecdotal opinion is this is also true in varying degrees for their opponents. We have seen a healthy dose of the Rays already so it's possible I've been somewhat jaded by that.

I heard Dewan on Rico Petrocelli's show on XM and he sounded like an advocate for the shift rather than a disinterested researcher. He's done some important work, but it is also worth bearing in mind that he has a substantial financial interest in convincing teams his data is very valuable....

The shift is killing Mark Teixeira.

The trending probably controls for most of this, but is it possible that the same hitters that are shift candidates naturally have a higher BABIP than others? (Thinking of quality of hitter, advantage of LHHs with runners on base, etc.) Could be one reason why the gap between non-'shiftees' and 'shiftees' is negative. Shifts may actually be driving down BABIP, but shiftees BABIP naturally higher than others, so a better test would be longitudinal trend in BABIP for just shiftees.

Like I said, the reason for the widening gap in favor of shiftee BABIP isn't explained by that, though, so it may not be relevant.

BIS could improve its data on shifts if the people recording the data were actually in the stands at the ballgames, no? It might cost BIS more, but wouldn't the greater accuracy be worth it?

Sabermetrics taught me a long time ago to not always trust my eyes. Colin's work reminds me to not always trust data that is very dependent on someone else's eyes, as well.

What about the damage that is done when a ball is put in play? If more line drives are getting caught but more ground balls are getting through, BABIP may stay the same, but TaV or whatever you want to use may be different on those hits.

"It doesn’t show where Desmond set up, simply where he was at when he fielded the ball. It doesn’t show the rest of the infield defense at all until Desmond makes the throw over to first."

Generally, instant replay from other camera angles, notably the camera on the first base side, shows pre-pitch positioning through the point of contact. I'm sure once the broadcast came back from the end of inning/commercial break, they showed at least two or three other angles just like they generally do mid-inning on a routine play.