Questions about UZR/150

[nate82]

I'm not sure if this is in the right spot so you can move it to the right area if it isn't where it should be.

 

I know there are a lot of stat gurus on here who could help me understand some of these questions I have about UZR/150.

 

First question how reliable is the UZR/150? Second question why is there such a disparity between years for example Mike Cameron's UZR/150 went like this; 11.9, 15.2, 3.4, 5.4, -7.2, and 13.3. I didn't include his 2005 season because he was injured that year. Why does did it swing like that? Someone of Mike Cameron's caliber in defense wouldn't it be more consistent?

 

Crawford has this happened to him to between the years of 2004 and 2008. As you can see here at fangraphs. I'm mostly wondering why Crawford went from 4.7 to 28.6 from 2007 to 2008.

[endaround]

For Cameron there has been talk that PETCO screws a lot of things up in the outfield.

[nate82]

For Cameron there has been talk that PETCO screws a lot of things up in the outfield.

OK but what about when he was with the Mets and that doesn't explain why Crawford went down so far playing in the same parks for the most part.

[kramnoj]

One thing that I've read from stats guys is that you need two years of defensive data to equal one years of batting data. So many plays that are made are routine that you need a couple of years to make the data from the non-routine data useful.

[Ennder]

It takes a good 2 years of offensive stats to really know how good a player is and it takes twice as long with defensive stats. Takes at least 500 IP or so with a pitcher as well.

 

Crawford was playing hurt(groin, wrist and ankle injuries) for a big chunk of 2007 and he played LF instead of CF which may make the UZR look worse (he picks some of that value back in the postional adjustement part).

 

Most likely 2007 is also partially just an outlier.