How bad is Soriano defensively?
Everyone's talking about Soriano's defense recently. Bruce Miles is pretty representative of the general mood:
Alfonso Soriano just may be the most maddening player in all of baseball.
Soriano giveth away.
If the Cubs played hockey, Soriano would be a "minus" player for the season.
But the play that will have most people talking this morning happened in the ninth, when Soriano was playing the field -- a place where he has become a measurable liability.
If you'll excuse a pedantic aside for just a minute - Miles claims Soriano is a measurable liability in the field, but doesn't provide what measurements he's looking at. I know Miles is a Baseball Prospectus subscriber, so I suspected he might be using the Davenport Translations. But Soriano's DT card shows him as a plus defensive outfielder so far this season.
[The DTs use Clay Davenport's Fielding Runs Above Average to evaluate defense; they're a form of adjusted Range Factor, so far as I can discern. The problem with adjusted Range Factor is that it uses things like pitcher handedness and team flyball to groundball ratio to fill in the gaps where there isn't enough data to make any conclusions, in much the same way that Jurassic Park's geneticists used frog DNA to fill in the gaps in their recovered dinosaur DNA. This is why adjusted Range Factors go on terrible rampages, eating people and destroying Land Rovers.
Okay, maybe that's just a reason they're unreliable.]
So I don't know what Miles is using as a source for that statement; I suppose that 90% of his readership doesn't particularly care about the intricacies of defensive metrics, so it probably wasn't particularly relevant to the article. I do know what defensive metrics I use; I explain Zone Rating in a previous post. Again, thanks to Jinaz for his method of converting BIS ZR into a plus-minus metric. [Note: ZR does not include any sort of an arm rating. Those are computed separately, and as of now I don't have any in-season data to compute that from.]
As of this morning, Soriano is -2.3 plays, or about two runs, below average. I don't think anyone would conclude that's good, but it's still an improvement over the likes of Adam Dunn.
What's curious is that the past two seasons, Soriano has been a plus defensive left fielder, according to zone rating metrics (again, not including an arm rating.) What's going on here?
First, it could just be a simple sampling issue. I know it looks like data and observation are converging here, but it's hard to draw definitive conclusions from only 56 chances. It's still very early in the season, and things could improve.
But if the data is correct, then I have two theories:
- Soriano's range is reduced due to his leg injuries; he's not getting to as many balls as he was the past two seasons.
- Felix Pie and Jacque Jones were both exceptional defensive center fielders; Johnson and Edmonds at this point in their careers are slightly below average. So perhaps having a plus center fielder corraling balls in left center masked some of Soriano's deficiencies that we're now just noticing.
They don't have to be mutually exclusive. If it's the first, we can hope that his defense will improve if/when he legs do; if it's the second, we can go a long ways towards remedying the issue simply by recalling Felix Pie and letting him try to play through his troubles on offense.
But Soriano's defense in the outfield is livable, especially for a team that's considering using Micah Hoffpauir as a starting outfielder.
[The biggest weakness on the Cubs defensively so far has been the middle infield - DeRosa's 1.8 plays below average, a substantial improvement over where he was a few weeks ago; there's reason to hope for improvement. Theriot is, to date, the third-worst shortstop in the NL according to zone rating, with 4.6 plays below average.
My gut feeling is that his inferior tools for the position are being overexposed this season, but that could just be a product of my incredible frustration watching him one-hop a throw to second base from the hole. I have enough of a reputation as a "Theriot basher" to have people take my opinions here skeptically (and please, be skeptical; fair and reasoned argument helps everybody learn more and think more critically about their own positions) but Theriot's defense so far has been a much greater liability to this team than Soriano's.]