Regressing defensive metrics

[HoustonGM]

http://www.fangraphs.com/blogs/index...ive-metrics-to

This is essentially a paraphrase of the concept of regression to different means. If we have two players with identical UZRs, but scouts love one and abhor the other, our projection for their relative UZRs going forward should favor the one preferred by scouts. The fact that observational information is available gives us a useful data point to add to the calculation, pushing forward analysis that leads to “best judgment”.

I said last week that I think Teixeira is probably a bit better defensively than his recent UZR scores have indicated, and the foundation of that belief lies in the value of scouting information. Teixeira is revered by almost every scout in the game as an exceptional defensive first baseman. That matters when we’re projecting future defensive performance. There is no reason to simply ignore those opinions simply because they don’t line up with what UZR has measured. We account for those opinions by regressing Teixeira’s UZR projections to a different mean than a player that scouts are less enamored of.

UZR is a tool. Scouts are a tool. They can be used together to produce better information than either can on their own. It is not an either/or proposition. Use both.

[rschusta24]

Hey Houston! I further learned a little more today about these metric statistics that you introduced me to, and I heard Terry Francona talk about it in an interview today. He was basically questioned if he felt he needed to use these statistics in order to manage games or evaluate how he plays his players and he said he is aware of the stats and does see the evaluation part of the players from them, but he says it is probably a better tool for the front office and not neccessarily for game aspects. They were specifically talking about Ellsbury and his UZR stats I believe (not entirely sure), which isn't as good as many people may think it would be. Besides all that, do you personally feel that these type of statistics are probably more useful for the front office and less for the game situations. I tend to agree with what Francona spoke of.

[HoustonGM]

They're useful in both aspects.

[rschusta24]

Thanks, I've been kind of wondering what you've thought of that.

As for the article, I really think a lot of good points are brought up. I've always been more in favor for some time now of the scouts trained eyes to find the best players, but as I have recently found out, the UZR stats definately have some relavence to a players abilities and have been used by successful GM's like Theo Epstein. When it comes down to it all, and there are simular UZR players being looked at, I think it would be smart for teams to make sure that they use both tools (Scouts&Metrics) to make decisions. The example of Texiera is a good one, I was very surprised to see that his numbers are lower than others when it comes to fielding, you really need to use that scout judgement to evaluate a player. I mean it's Mark Texiera! haha.

[actionjackson]

I'll fix that for Dave Cameron: UZR is a tool. Scouts are tools.

All kidding aside though, since I discovered the more advanced metrics, I've always thought that player evaluation needs to be scouting fused with metrics. Why? Simple: in most crime investigations there are a lot of inconsistencies in the eyewitness statements. The eyes can deceive even the most perceptive people. Then, there's that old saying about "Lies, damned lies, and statistics". Numbers don't always tell the whole story when one is evaluating a player. Use both eyes (subjective and objective). Why would you put out one eye and reduce your ability to see things clearly? Especially when you're talking about the kind of money that is spent on baseball players.

[BenFink]

Fielding has always been most difficult to analyze, but I believe it is too easy for a scout to be fooled if they do not using metrics. It's similar to things like strikeouts in pitching and steals and home runs in hitting, exciting plays make the mind think the player is better.
What's more exciting? A player making a diving catch in the outfield for the out, or an outfielder who correctly positioned themselves so that the play would be easy? The former, but which player was the better fielder? The latter. But most importantly, who do you think the scout will favor more? Probably the person which was more exciting, which is brain perceived as better.

[OregonDuck1989]

This was on ESPN.com today.

[HoustonGM]

Fielding has always been most difficult to analyze, but I believe it is too easy for a scout to be fooled if they do not using metrics. It's similar to things like strikeouts in pitching and steals and home runs in hitting, exciting plays make the mind think the player is better.
What's more exciting? A player making a diving catch in the outfield for the out, or an outfielder who correctly positioned themselves so that the play would be easy? The former, but which player was the better fielder? The latter. But most importantly, who do you think the scout will favor more? Probably the person which was more exciting, which is brain perceived as better.

Pretty much, yep.

And all too often, ONE play completely changes the perspective of a player's fielding, and that's just idiocy. Plain and simple idiocy. Gary Matthews made a spectacular catch. That means he's an excellent fielder. Matt Holliday made a terrible error in a playoff game. That means he's a dreadful fielder. It's ridiculous. Would we change the reputation of a hitter based on one at bat? Never. Why does it happen with fielding?