The Value of Swapping Positions

From SABR member Jeremy Greenhouse at Baseball Prospectus on April 7:

In an offseason packed with turmoil and turnover but bereft of big-money acquisitions, the Mets made one high-profile on-field move by swapping Carlos Beltran and Angel Pagan in the outfield. Even though Beltran still feels that he could play center, he offered to move to right field to save his knees and supplement his offense at the risk of losing defensive value …


Two players on the same team trading positions is an interesting phenomenon, requiring a lack of stubbornness and a willingness to learn on the parts of both player and management. How have positional swaps worked throughout history?

I searched for all instances where two players exchanged positions and were in the field for at least 50 balls in play at each position, and then I totaled both the team’s and the players’ individual defensive efficiency ratios in specific cases to determine whether the swap “worked.” Since the beginning of the Retrosheet era, the right-field-to-center-field switch has occurred most frequently.


A more comparable case of an All-Star-caliber player bowing to a quality outfielder in his own right would be the Twins’ transition from Kirby Puckett to Shane Mack 20 years ago. With Mack in right and Puckett in center, the Twins had played over 100 games with a .714 DER. Puckett switched positions with Mack, and in the 95 subsequent games the pair played together, the Twins’ DER fell to .685.

A more recent pairing of established players switching positions came just one decade ago. In 1998 and 1999, Garret Anderson played center field for the Angels, while Darin Erstad manned left.

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Originally published: April 7, 2011. Last Updated: April 7, 2011.