March 5, 2013
Why Multi-Position Players Matter
We’re a little closer to being able to put a number on it now, thanks to one of the Research Paper Finalists at the 2013 MIT Sloan Sports Analytics Conference held in Boston this past weekend, “The value of flexibility in baseball roster construction.” You can read the whole paper here (PDF). (Warning: intimidating equations.)
The authors, Timothy C.Y. Chan of the University of Toronto and Douglas S. Fearing of the Harvard Business School, drew inspiration from “the theory of production flexibility in manufacturing networks” in their attempt to quantify the contributions of multi-position players. What that means, in practice, is treating baseball players like factories that produce car parts:
It’s a clever approach, and it yielded some intriguing results. The authors studied how likely players are to get hurt, and for how long,* as well as how they perform in the field at their non-primary positions. Then they developed a model to calculate how much team performance suffers as a result of injury, and to assess the difference in the magnitude of the impact on teams with and without many multi-position players.
*In summary: older players are more likely to get injured, but not to miss more time when they do.
Their conclusion? Flexibility matters, not only because it aids teams in overcoming injuries, but because it helps them gain the platoon advantage more often. The most-flexible team in their simulations of the 2012 season (the Cubs) added 30 runs above replacement, or 15 percent of their overall offensive value, due to flexibility alone. The least-flexible team, the White Sox, added only six runs, or 3.4 percent of their overall output. Although they studied the effect of flexibility only on the team level, the authors note that the “same optimization model can be adapted to quantify the value of flexibility each player provides his team.”
If anything, the authors’ model is still underrating the value of multi-position players, since much of the benefit of a flexible roster comes in the planning stage. As I wrote in my Prado piece, “Not only do multi-position players enable teams to maximize the returns on their roster by helping them avoid replacement-level production when guys get hurt or face an unfavorable matchup, they also give general managers greater flexibility in putting their rosters together, warding off weak positions in the first place.”
That doesn’t mean just any old multi-position player will do: as the authors note, “Although it provides a team with options, flexibility alone may not be enough. A team needs flexibility and capability–that is, players with the ability to play multiple positions with skill.” But it certainly suggests that there’s real value in acquiring or developing players who can float all over the field, even if it doesn’t show up immediately in a team’s projected WARP total. Which reminds me of a few paragraphs from an article I read a few days ago:
The Rays are already exploiting multi-position players to eke out a few extra runs from their roster, but any advantage they have in that area won’t last long. For many teams, the future might hold a bench full of Bloomquists.