Mark DeRosa needs a raise

Recently, 34-year-old Mark DeRosa was traded from the Indians to the Cardinals. The occasion brought to light an aspect of DeRosa’s value that is overlooked (or, at least, under-enumerated).

That aspect is DeRosa’s versatility. Thus far in 2009, DeRosa has played 44 games at third base, 17 games in left field, 9 in right field, and 8 at first. Last year, his main spot was 2B (95 games), but he also played at least 20 games at 3B, LF, and RF, along with one game each at 1B and SS.

Such flexibility is not trivial. Why did St. Louis want DeRosa? As Rotowire.com put it, DeRosa “can play all over the infield, which makes him a perfect fit for the Cardinals.” Assuming this is true (and it’s almost inarguable), then there is an element of DeRosa that we need to account for. Sure, we can go through and total DeRosa’s Wins Above Replacement at each position. But that exercise dodges the value of the ability itself to play multiple positions.

There are two major ways in which DeRosa provides greater value than does a player of the same total WAR but single-position eligibility:

1. Higher resale value

Because DeRosa can play multiple positions, he can fill holes on a larger number of teams; hence, the demand for his services is stronger and so the winning bid should be higher. (This is true even if each team intends for DeRosa to play only one spot; it’s the volume of bids that matters here.)

Cleveland almost certainly fielded more offers for DeRosa—and hence got a better deal for him—than if he played only one spot. Likewise, in the expert fantasy league LABR, the winning FAAB bid for DeRosa was so high ($80!) in good part because most teams could justify submitting bids. (There may even be an add-on effect, whereby teams pay a premium because they know that DeRosa will be easy to off-load later.)

If you want a bargaining chip, you can’t do better than one that appeals to every buyer.

2. Easier replacement of teammates

Because DeRosa can play multiple positions, he indirectly expands the list of tenable substitutes at positions that he can play but that he’s not currently playing. Your left fielder goes down? Well, you can keep DeRosa at 2B and look for a LF—or you can put DeRosa in LF and look for a 2B. Whichever’s better.

The thing to note about this factor is that it’s REUSABLE—each time that DeRosa’s team loses a player at a spot that DeRosa can play, DeRosa’s owner can cast a wider net for fill-ins. And a larger pool of candidates should mean a higher-caliber substitute. (Note that we are not saying that DeRosa has the same value at each position, only that he expands options.)

Moreover, DeRosa’s owner can discriminate not only among overall value but among the nature of that value—maybe the team wants speed, maybe they want a left-handed bat, maybe they want a closer. Whichever the case, more applicants means a better fit.

Imagine two teams. Every player has the same relative value for his position, but on one of the teams, players can play only one spot, whereas on the other team, players can play every spot.

Which team will finish with the better record? The first team—IF two things are true:

1. Players are inconsistent. If players never got hurt or had bad genuinely match-ups, or they never went on stretches that (rightly or wrongly) left them open to demotion, then positional flexibility wouldn’t matter because players would never need to be replaced.

2. Replacement talent is not evenly distributed. If every replacement player who was available to a team had the same relative value for his position, AND talent was evenly distributed among replacement players such that players were identically skilled from both sides of the plate, on the basepaths, and with the glove, then positional flexibility wouldn’t matter because no player would address a need better than would any other.

Fortunately, both things are true: Players are inconsistent, and replacement talent is not evenly distributed. And if the first team does beat out the second team, then our notion of “value” must be incomplete.

In fact, it seems to me that NO extant valuation method properly accounts for DeRosa’s versatility. Valuation systems generally treat a season as a set of numbers—add up the player’s contributions at the plate and in the field and you have his value. However, a season can also be seen as a string of events (some within a team’s control, some out of it). In that light, finding a player’s value entails not a comparison of that player’s success to the success of other players at his position, but a comparison of his team’s success to the success of teams (real or conceived) that lack the player.

Current valuation models are static. They miss that flux; they miss the ebb and flow of a season.

Mark DeRosa “makes his team better,” not because of pats on the back but in a true economic sense: He expands the options for the team when one of his teammates goes down, or when the team is looking to deal him for a needed quantity.

Whatever Mark DeRosa’s making, it’s not enough.