Nyjer Morgan: How Valuable Is Defense? Part One

Sixty Feet, Six Inches Correspondent IAugust 12, 2009

DENVER - JULY 08:  Centerfielder Nyjer Morgan #1 of the Washington Nationals tracks down a fly ball against the Colorado Rockies during MLB action at Coors Field on July 8, 2009 in Denver, Colorado. The Rockies defeated the Nationals 10-4.  (Photo by Doug Pensinger/Getty Images)

I'm going to go out on a limb here and make an assumption. I'll assume for a moment that the majority of our readers have either read or at least understand the premise of the book Moneyball.

However, what a good deal of people don't know is that Billy Beane himself shifted focus shortly after Moneyball was released.

See, the underlying point of that book isn't about stats. It's about a small-market team—in this case the Oakland Athletics—finding a niche that hasn't been exploited by teams with more money yet. In this way, they gain a competitive advantage.

At this point, if all the fans know about the revolution of sabermetrics, you can bet that every front office knows about them, too.

Bill James works for the Boston Red Sox now. The Yankees cite OBP in articles on MLB.com. The competitive edge gained has leveled out.

So what did Beane do?

Simple. He exploited something else that many large-market teams ignored. With the offensive revolution going on, Beane built his teams around defense.

But I'm not here to talk about Billy Beane and what he's done with his teams. Michael Lewis has done that quite well, and hundreds of sports writers have since beaten that dead horse.

This post will instead focus on the premise of a conversation I recently had with the author of Fire Jerry Manuel regarding Nyjer Morgan's impact on the Nationals and their win streak.

This post is annoyingly long and analytical, so I'm going to put a jump here for anyone that wants to skip over it. If this subject interests you, read on.

I'm going to ignore the offensive contributions Morgan has made to the Nationals' lineup. Currently, Morgan is hitting in a very un-Morgan-like fashion.

Sorry Nats fans, I know he's been on a tear lately, but he did this in the beginning of the year in Pittsburgh as well. If he doesn't regress, I'll be a blue-nosed gopher. Tony Plush may be good for a .300 average, but that's about it with the bat.

Instead, I'm going to talk (primarily) about Morgan's defense.

The stats I'll be using are Ultimate Zone Rating (UZR) and its rate companion, UZR/150. I'll then use Wins Above Replacement (WAR) to illustrate just how valuable Morgan's defense actually is.

For those of you unfamiliar with UZR, it's widely considered to be the best defensive statistic made available to the public. If anyone wants to see all the details of it, Baseball Think Factory did two lengthy posts here and here.

In summary: UZR assigns each fielder multiple zones of responsibility. The zones grow and shrink depending on what type of ball is hit there. For example, a line drive results in a smaller zone of responsibility based on how much more difficult it is to make that play than one on a lazy fly.

In contrast, the lazy fly expands the zone based on how much easier it is to make the play.

UZR is then calculated by measuring how many plays are converted into outs when hit into the fielder's zone. This is compared to a baseline that's calculated according to how many other fielders made the play in the same zone. It's then adjusted for things like park factors and handedness of the fielder.

UZR/150 is just a player's UZR expanded to 150 games.

What we see when we look at Nyjer Morgan's UZR is fantastic.

This year, Morgan's UZR/150 of 27.7 is ranked higher than all outfielders in the major leagues. This includes his time with Pittsburgh when he was playing in the less defensively-challenging left field, however, so it doesn't give a full picture.

Counting only his games in center—where he plays in Washington—Morgan's UZR/150 is 30.4, which is higher than everyone but Chris Dickerson and Andres Torres among players who have played at least 10 games in CF. Considering that Morgan is a regular CF while Dickerson and Torres rarely play there, speaks volumes.

However, we should remember that UZR/150 is a rate stat and thus more likely to be influenced by small sample sizes. Morgan's 44 games in center aren't a sample that one could consider "large."

So, let's take a look at raw UZR. Remember, UZR is a counting stat, not a rate one. Thus, Morgan would actually be at a disadvantage by having less playing time in center.

What we find, however, is that out of all players that have played center this season—even for one game—Morgan ranks second in raw UZR. That's among 122 players that have manned center at least once this year. The only player ranked ahead of Morgan is Franklin Gutierrez, who has a 60-game edge.

So how valuable is Morgan's defense?

I mean, he still can't hit for power, (his three HR this year is a career high, unless we count the year he hit four in A-ball.) and he gets thrown out too much on the base paths—he leads the majors with 16 caught stealing and has a stolen base success rate of just 70 percent. He's just a great defensive sub and fourth OF, right?

Not so fast, my friend. It turns out that a .307/.370/.388 line can be pretty valuable provided the fielding is superb. Even if you DO lead the league in caught stealing.

This is the part where we use wins above replacement (WAR.) for those of you familiar with VORP (value over replacement player), think of it as VORP, only it includes defense and adjusts to fit the "10 runs = 1 win" maxim.

WAR works by taking the amount of runs a player produces with the bat, adding it to the number of runs saved with the glove, and subtracting the performance one could expect from a replacement level player at that position.

It is then adjusted for position (you don't want to value an average-fielding 1B just as heavily as an average-fielding C or SS, for example) and finally multiplied by .10 to conform to the standard of 10 runs = 1 win.

For the more hardcore among you who want to see the exact calculation process of WAR, see this link.

What we find when we look at Morgan's WAR is that, of all MLB players, he is ranked 11th in value. The only OFs who rank higher than him are Ben Zobrist (who plays just about everywhere on the diamond) and Matt Kemp.

Even if we take away Morgan's time in the less defensively-challenging left field and focus solely on his starts in center field, only Kemp ranks higher than him among full-time center fielders. This remains true even if we do what I did earlier with UZR and include anyone that's played even one game in center this season.

I'm not just making this up, folks. Here's the data at FanGraphs.

So...is Nyjer Morgan a big reason for the Nationals' turnaround? Yeah, probably.

Was the Morgan-for-Lastings Milledge deal a good one for the Nationals? That is far less certain. I'll examine that in a post tomorrow. Stick around.

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