Saturday, November 6, 2010

Flawed defense, flawed numbers

From a comment to my Friday post:

So the Twins had the best second baseman, a very good shortstop and a good centerfielder and defense hurt them? Am I missing something?

Perhaps. Like this game. And this game. And this utter travesty. And ...

A slimmer Delmon Young looked better
on defense in 2010 to most fans,
but the defensive metrics say he was as
bad as before. So do you believe your
lying eyes or the newfangled stats?
Let me back up. I did a lousy job on the Friday post. It was supposed to be about Nick Punto's rather remarkable plus-minus and runs saved numbers, and it wound up being about almost everybody else's first — and the underlying problem with the whole idea is that I don't completely trust those stats to begin with.

I like the idea behind the stats, but just try to describe how Baseball Info Systems decided that Punto saved eight runs over an average third baseman in just 344 innings, or seven runs over the average shortstop in just 258 innings. You can't. I have the books, and they can't describe it well.

What's more, they don't fully trust those numbers either. That's why they supplement the 2010 leaders with a rolling three-year figure, and why they left Punto out of the leaders rankings.

Several years ago, when BIS rolled out plus-minus, I wrote a Monday print column on how we're being asked to take these fielding metrics on faith. Unlike the hitting stats, they can't be readily audited. If you doubt that Joe Mauer hit .327 last season, you can go through the box scores and check it yourself. If you question his 91 runs created, you can work though the formula. If you doubt that Orlando Hudson was +23 in plus-minus, you literally can't figure it yourself.

I'd rather know the plus-minus and runs saved stats than not. But I'll continue to doubt their validity as long as I'm watching players who look good in those numbers give away outs and runs and games.

Back to SoCalTwinsFan's comment:

So, the Twins are weak defensively in three of eight positions on the field and those three are the least important on the field, RF, LF and 1B.

Are they the least important? No; they are the least demanding, which is a different concept altogether. Let's ditch for the moment my reservations and work with runs saved. Over the past three years, Hudson has saved his teams 18 runs. Delmon Young, by the same measurement, has cost his team 27. If a run is a run, Young is costing his team more runs than Hudson saves.

It takes more ability to play second base at a major league level of skill than to play left field. That is undeniable. That doesn't mean the runs Hudson saves are more important than the runs Young allows.


  1. Punto is a terrible player and I hope we never have to watch him play in Twins iniform again.

  2. We already have Nick Punto Jr. in Matt Tolbert, in my eyes Punto brings no value to our team, we have utility players already who can do just as good of a job as Punto. Punto has no business starting on any major league team and I have suffered watching him be a starter and bring our team down for far to long. I hope we finally found a way to keep him out of our lineup forever with the emergence of Valencia. If we don't bring O-dog or Hardy back I hope more than anything that Punto is not resigned and in our starting lineup ever. Casilla is better than Punto and if there are any spots to fill in the infield than give a prospect a chance to play. Give the starting job to a player who has some upside if nothing else instead of Punto's worthless bat and over rated defense.

  3. Point well taken, but when all the pluses and minuses are added up, the Twins came out as the second-best team in defense, at least according to both BIS and UZR, two completely different defensive metrics. I'm as skeptical as anyone with the ability to quantify defense, but when two different systems both agree that the A's were the best in the AL and the Twins were second best, that lends some validity to what they're trying to do.