Does the "Ted Williams Shift" make sense?

Based on data from Baseball Info Solutions, there are seven guys in baseball for whom most teams play the "Ted Williams Shift." That is, they put three infielders on the right side of second base hoping that the defense will come up with more plays due to their expectation that these players will pull the ball way more often than other players. The seven players are Big Papi (David Ortiz), Ryan Howard, Carlos Delgado, Jason Giambi, Ken Griffey, Jr., Jim Thome, and Adam Dunn.

In The Fielding Bible—Volume II we show our Defensive Positioning charts for about 25 of the more interesting players in baseball, including some of these shift–inducing hitters. Do these guys pull the ball more than other players? Here are the numbers for these seven guys:

Note: based on the last 120 grounders and short liners hit by each player (including postseason).

Here's my rule of thumb: if a hitter hits significantly more than three out of every four balls in the infield (75%) on the right side, you should put three out of your four infielders on the right side.

There are about 30 more left–handed hitters in baseball who hit over 80% of their grounders and short liners to the right side of second base, including Chase Utley, Carlos Pena, and Alex Gordon. Teams should consider shifting on many of these guys. Of all the players I've mentioned, bunting is not something to worry about except for maybe Carlos Pena, who has attempted six bunts in his last 300 plate appearances, a higher rate than any of the other players.

The one questionable player is Adam Dunn. At 80%, I consider shifting on Adam Dunn marginal. Here's why: The third baseman has a ton of ground to cover to handle 20% of the grounders, while each other fielder has a small amount of ground to cover to handle, theoretically, 26.7% apiece. The 20% compared to the 26.7% is too close. I'd like to see it more like 15% for the third basemen and almost double that for each of the other fielders. Plus, unlike some of the other hitters who get the shift, the 20% that Dunn hits to the left of second are pretty spread out.

Even more interesting to me is that there are several right–handed hitters who pull their batted balls to the left of second base over 90% of the time. That's a higher pull rate than any of the lefty swingers. Jason Bay, Garrett Atkins, Ben Francisco, Marcus Thames, Kevin Youkilis. I think teams should consider the righty–shift on these guys, three infielders to the left of second base. Defensive positioning diagrams for all five of these players can be found in The Fielding Bible—Volume II.