Granderson’s Defense Not Easily Evaluated

From SABR member Mark Simon at on September 2:

In the sixth inning Thursday night, Yankees center fielder Curtis Granderson made a sprawling catch to end a Red Sox threat.

There are certain plays that Granderson is very good at making. This was one of them (as Chris Singleton details in the video above). He’s made his share since becoming a member of the Yankees in 2010.

But how do we reconcile that with a statistic that shows Granderson’s defense rates among the worst in baseball?

This was a hot topic recently regarding Granderson’s MVP candidacy, and a fear that these defensive metrics will hurt his postseason award chances.

That’s a question that only MVP voters can answer. What we want to look at is why Granderson’s defensive rating is what it is this season.


How is Granderson’s defensive value computed?

There are several systems that look at data in different ways. All agree that this is a down defensive season for Granderson. We’ll look at one system more closely. It was designed by sabermetricians Bill James and John Dewan of Baseball Info Solutions (BIS) and calculates both a Plus-Minus Rating and a Defensive Runs Saved rating.

The key component to these metrics is how well a fielder turns a batted ball into an out, regardless of whether the play is a hit or an error. BIS has a group of trained film-watchers who input batted ball information onto a baseball diamond grid.

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Originally published: September 2, 2011. Last Updated: September 2, 2011.