Syria isn’t the only place where we ask “Why War?” Some ask the same question about baseball. In baseball lingo, “WAR” stands for Wins Above Replacement, an advanced statistic that played a prominent role in last season’s MVP debate, and will be prominent again as this year’s voting nears.
In 2012, Miguel Cabrera won the Triple Crown; he was widely known as the league’s best hitter. However, Mike Trout was clearly the superior base runner and defensive player. Historically, there was no good way to determine whether Trout’s base running and defense overcame Cabrera’s hitting in an overall evaluation. This was simply a matter of opinion, akin to the old question of DiMaggio vs. Williams. Such unresolvable debates kept bars in business.
Except we now live in the information age, and “sabermetricians” (the advanced stats gurus) seemed to shape the debate with the development of WAR. WAR yields a single number for each player’s overall contributions by combining separate assessments of hitting, base running and defense (with additional adjustments, and with separate evaluation of pitching).
The several component measures of WAR are each expressed in the common unit of runs (added or lost). These are added together to yield a final run value. Runs are converted into wins, and wins are compared with a hypothetical minimum-salary “replacement” player. Thus, the final term: Wins Above Replacement (player).
The three well-known WAR formulations (from Baseball-Reference.com, fangraphs.com and Baseball Prospectus) all ranked Trout first in the American League in 2012, with Cabrera third or fourth. Thus, some in the mainstream media insisted that Trout, rather than Cabrera, should have been MVP. Similarly, in 2013, Trout leads the American League in all three WAR formulations, with Cabrera second or fourth.
But is WAR valid in ranking players over one season? For WAR to provide an accurate assessment of players’ relative values, each of the three individual metrics — for hitting, base running, and defense — must be accurate. (This is putting aside the issue of intangibles — leadership, hustle and other factors that elevate players like Pete Rose and Derek Jeter beyond their statistics). Defensive and base-running performance will form the crux of this analysis because they are generally considered the most difficult to measure.
The three WAR formulations use different defense and base-running measuring systems, but they track similar ideas. The best-known defensive system is probably Ultimate Zone Rating (UZR), which we can analyze as a representative system. Briefly, UZR evaluates a fielder on every play by comparing the outcome of the play to historical results of other players on similar or, ideally, exactly alike batted balls; a certain kind of ball (i.e. velocity, trajectory, etc) hit to a specific spot on the field. This is an attempt to isolate the player’s ability as the single variable corresponding with the play’s result. This analysis is repeated for all batted balls for the season, and the final tabulation yields a quantitative assessment of each player’s defensive performance.
Does UZR accurately capture a fielder’s performance? We can’t know for sure, but we do know that UZR and similar systems produce some seemingly bizarre results. According to UZR, Alfonso Soriano, universally regarded as a poor outfielder, turned in the single best defensive season (in 2007) of any player from 2002 to 2012. In fact, two years before his unprecedented defensive season, Soriano was graded as terrible by UZR. In 2013, age 37 and virtually immobile, he bounced back for a strong rating. According to UZR, Jeter went from terrible to very good and back to terrible quite quickly. Albert Pujois and Jayson Heyward had better defensive seasons than Omar Vizquel’s best. In Baseball-Reference.com’s defensive measurements, Willie Mays does not have one of the best 500 seasons ever, a list that includes Roberto Clemente only once. Joe DiMaggio was barely better than average.