Previously, we had Fielding Metrics Made Easy, and Fielding Metrics Made Somewhat Complex. Now, we've basically reached the level of numbers which I can only make a vague stab at clarifying. I have read the explanations, and despite my high tolerance for figures [two years of college statistics and a mis-spent youth playing D&D], my brain still got glazed over faster than a batch of hot Krispy Kremes. I suspect that these are numbers which only God and that bloke off Fringe can truly claim to understand.
An example would be Clay Davenport's work for Baseball Prospectus, which results in a measure called FRAA, for Fielding Runs Above Average. The BP site seems quite coy about the precise scheme behind it,, which appears to be semi-proprietary. But second-hand reports suggest "It takes a fielder's range factor and makes adjustments for innings played, team defense, estimated ground ball/fly ball data, strike outs and some other things. It then compares the range to league average and estimates the number of runs saved above or below average." Pixie-dust may, or may not, be among the "other things" which are taken into account. There are a good example of baseball statistics as a religion; you just have to have faith, and accept the dogma sent down from on high.
Going even beyond FRAA, there is FRAA2, which "incorporates adjustments for league difficulty and normalizes defensive statistics over time." That sounds shiny and impressive, so I'm going with that. I'm not quite sure how the system tracks players like Jackson, who played multiple positions; I assume it probably sums the values obtained at 1B and LF. Leading the way for Arizona here is Orlando Hudson, with a rating of +13. Chris Young had the same FRAA total, but played a lot more innings at his position. Unlike some of the defensive metrics, it does measure catchers. and Chris Snyder performed well, at +11, ahead of - and this might be a surprise, Chris Burke, with +9. Conor Jackson rounds out the top five, scoring +8.
At the other end of the spectrum... FRAA2 gives a resounding raspberry to Mark Reynolds, with only one player in the majors getting a worse rating than the -18 awarded to Reynolds [that being Rockies' right-fielder Brad Hawpe, at -23 - though see the comments at the end of Part 2, about the dangers of directly comparing stats across positions], Special K's figure was twice as much as that of the next worst Arizona player. That dubious honor went to Justin Upton (-9), though Stephen Drew wasn't all the far behind at -7. Backup outfielders Alex Romero (-5) and Jeff Salazar (-4) were also significantly negative.
Finally, Fangraphs.com recently added another fielding metric to the stats on their site. This one is UZR - Ultimate Zone Ratings. If you want more info on how it's worked out, please see here, but there are two factors involved, Range Runs and Error Runs. The former is the runs +/- average, determined by how the fielder is at getting to balls hit in his vicinity. The latter is the same, but based on the number of errors compared to an average fielder. Both stats depend on the distribution of balls in play hit to him, and their sum gives you the overall UZR. So it combines, to a certain extent, the subjective measure of errors, and the objective one of the difference in balls reached, compared to an average player. The guy who originally came up with UZR, Mitchel Lichtman, now works for the St. Louis Cardinals.
The following chart has all the Diamondbacks who played 100 innings or more at a single position. Also shown are the Range Runs and the Error Runs, with the sum of these being the UZR. The final column scales the UZR to take into account the different number of innings played.
Looking at the results here, the phrase that springs immediately to mind is: "God, Adam Dunn sucked, didn't he?" We could probably have put a zombie in right - and one of the slow, Romero ones at that - and got better range than Dunn showed. He was somewhat better at first, albeit in part because we got to see less of him there. In contrast, notice the great performance of Augie Ojeda all over the diamond: if you add up his UZR at those three positions, he comes out at 7.1, the best number of anyone on the team. Given the questionable numbers for most of our infield [and in case you're wondering, Felipe Lopez at 2B was -3.5/-0.6/-4.1/-4.6 - which are actually better numbers than O-Dawg last season], expect Ojeda to get most of his starts with Brandon Webb on the mound.
It's also interesting to contrast the results produced on the left-hand side of the infield, by Reynolds and Drew. The split of Special K's numbers is particularly stark: his Range Runs were actually the best on the team, but were wiped out by the negative impact of all the Error Runs he accumulated. On the other hand, Drew had very steady hands, but his poor range suggests an alternative career for him would involve Stephen's use to block off lanes during road-works on the Loop 101. These two provide a contrast in how the old math [errors and fielding percentage] may not paint the entire picture of defensive skills.
Moving to the outfield, our 'best' glove, taking playing time into account, was Chris Burke? That may be the first - and only - time in 2008, that the words "best" and "Chris Burke" have been used in the same sentence. UZR concurs with most of the other metrics as far as Jackson goes, finding him a good bit better in RF than at 1B [the shift in position there isn't too drastic, as far as difficulty goes] Chris Young doesn't come off particularly well here: he's positive, but only just so. The right-field position appears to have been a Bermuda Triangle of Defensive Suckitude, pretty much regardless who was there: as noted, Dunn was the worst, but neither Romero nor Upton proved a net positive there.
So, what have we learned? Probably that there is still no one metric, as yet, which we can point to and say, "That is an accurate measurement of defensive skill." For some players (such as Stephen Drew), there does appear to be a general consensus of the various systems, which can cause us to label a player as better than most, average. or deficient with the glove. However, there are others for whom there is no such agreement. Orlando Hudson would be one: FRAA2 thinks he's the best defender on the team, while UZR laughs sarcastically at that, and reckons O-Dawg is well below average. Research will, no doubt, continue. But if I don't see another fielding metric before Opening Day, I can't say I'll mind too much.