MLB ump schedule covers all the bases

MICHIGAN STATE (US) — Scheduling umpires for Major League Baseball’s entire 2,430 game season is a daunting task. And that’s if you know what an umpire is to begin with.

Growing up in soccer-crazed Turkey, Hakan Yildiz, assistant professor of supply chain management at Michigan State University, didn’t know much about baseball.

But a complex scheduling system he developed with Michael Trick of Carnegie Mellon University and Tallys Yunes of the University of Miami, is so effective the league has used it for five of the past six seasons.

The method is published online in the journal Interfaces.

“Major League Baseball has benefited from this study. The umpire schedules are more balanced and have fewer violations of league-imposed travel rules and restrictions,” Yildiz says.


MLB teams play more than 2,000 games in two- to four-game series during a six-month season, with each game officiated by a four-person crew.

Scheduling is difficult, because of constraints such as union-mandated vacations and league rules that regulate, coast-to-coast travel and potential overexposure to individual teams. To avoid overexposure, for example, each umpire crew is expected to, among other things, travel to all 30 ballparks at least once during a season.

The researchers set out to develop methods to create better schedules while accounting for the myriad constraints. To test their methods quickly, key issues were identified and idiosyncratic constraints such as an umpire’s preferred vacation dates were disregarded, allowing them to test alternative methods using simulated data.

In 2006, MLB decided to use the research team’s schedule—the first time the league had done so for an outside consultant. The league used another method in 2007 and then returned to the Yildiz/Trick/Yunes method for the 2008, 2009, 2010 and 2011 seasons.

One improvement stemming from the research team’s method involves the league’s 18-day rule violation, which says that a crew shouldn’t umpire the same team’s series of games more than once every 18 days—but in 2005 this happened 16 times. Under the new schedule, it didn’t happen at all in 2008, 2009 or 2010.

Yildiz still hasn’t become a baseball fan. “For me, I like the fast-moving games,” he says. “Baseball is a slow-moving game; it takes too long. I still can’t seem to get my head around it.”

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