27 replies to this topic

[King Jeff]

Why is it troubling that there is so much variation in year to year defense? We see the same year to year fluctuations in pitching and hitting.

Starlin Castro's UZR dropped from -2.7 to -8.7 from 2010 to 2011. He committed 2 more errors last year in 300 more innings, there is no way his defense got that much worse. Tell me where that much variation came from.

Yeah, there's fluctuation in hitting and pitching, but nothing like the kind of swing I pointed out in Byrd (which is commonplace in UZR). Further, it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching.

Jacoby Ellsbury Hr's.
Adam Dunn's OPS
James Shields ERA

Those swings aren't as big as the UZR jumps?
I'm no UZR supporter by any means, but I think they jump around just as much as a players AVG, a players HR's, a players RBI's, ERA, Whip, etc....

The problem is that defense isn't supposed to jump around that much. If anything, defense should improve with age. Also, from what I've seen, the stats don't justify the UZR jumps and drops, which is why it confuses me.

[hansman1982]

The problem is that defense isn't supposed to jump around that much. If anything, defense should improve with age. Also, from what I've seen, the stats don't justify the UZR jumps and drops, which is why it confuses me.

Actually, defense is the first thing to decline even before speed, while decision making on defense should improve with experience, reaction times, reflexes, the "phyiscal" side of defense makes it more difficult to get to the ball. In theory, Castro will hit his defensive prime next year and decline after that. He will start to lose the ability to get to the fringy balls that account for most of his errors right now that makes him a plus defender without the mental side.

[hansman1982]

Also, why should fielding be the one area of a players game that can't swing wildly? Looking at Albert Pujols during his age 26 season he hit homers at a 7.7% clip and the following season he hit them at a 4.7% clip and his OPS dropped over 100 points. Should we disregard the OPS stat? No, we look at OPS as a part of the bigger picture, same as to how we should view UZR, part of the bigger picture.

[NormB]

The problem is that defense isn't supposed to jump around that much. If anything, defense should improve with age. Also, from what I've seen, the stats don't justify the UZR jumps and drops, which is why it confuses me.

Actually, defense is the first thing to decline even before speed, while decision making on defense should improve with experience, reaction times, reflexes, the "phyiscal" side of defense makes it more difficult to get to the ball. In theory, Castro will hit his defensive prime next year and decline after that. He will start to lose the ability to get to the fringy balls that account for most of his errors right now that makes him a plus defender without the mental side.

This.
Defense peaks EARLY....WAY early.
And I don't see why there shouldn't be as many swings defensively as with offense or pitching? You can't use errors, for anything. UZR doesn't care about errors. What one scorekeeper calls a hit, UZR will still say "he didn't make that play". If a player gets an error on an impossible play, UZR won't punish him.

[Brett]

Why is it troubling that there is so much variation in year to year defense? We see the same year to year fluctuations in pitching and hitting.

Starlin Castro's UZR dropped from -2.7 to -8.7 from 2010 to 2011. He committed 2 more errors last year in 300 more innings, there is no way his defense got that much worse. Tell me where that much variation came from.

Yeah, there's fluctuation in hitting and pitching, but nothing like the kind of swing I pointed out in Byrd (which is commonplace in UZR). Further, it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching.

Jacoby Ellsbury Hr's.
Adam Dunn's OPS
James Shields ERA

Those swings aren't as big as the UZR jumps?
I'm no UZR supporter by any means, but I think they jump around just as much as a players AVG, a players HR's, a players RBI's, ERA, Whip, etc....

We could play the "let's find examples" game all day. Very few stats have a guy being one of the best in the game one year to being one of the worst in the game the next year with the kind of regularity you see it in UZR.

And, again, I say: "it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching." The fact that there are wild swings in offensive performance or pitching doesn't disprove my theory - it actually supports it.

Does anyone really want to dispute that?

[King Jeff]

The problem is that defense isn't supposed to jump around that much. If anything, defense should improve with age. Also, from what I've seen, the stats don't justify the UZR jumps and drops, which is why it confuses me.

Actually, defense is the first thing to decline even before speed, while decision making on defense should improve with experience, reaction times, reflexes, the "phyiscal" side of defense makes it more difficult to get to the ball. In theory, Castro will hit his defensive prime next year and decline after that. He will start to lose the ability to get to the fringy balls that account for most of his errors right now that makes him a plus defender without the mental side.

Defense definitely declines with age, but I think you are way off when saying that a guy is a better defender at 22 or 23 than he will be a 28 and 29, which is the physical peak for most professional athletes. I haven't done a lot of research, but most of the players I remember were at their best defensively in their late 20's.

[NormB]

The problem is that defense isn't supposed to jump around that much. If anything, defense should improve with age. Also, from what I've seen, the stats don't justify the UZR jumps and drops, which is why it confuses me.

Actually, defense is the first thing to decline even before speed, while decision making on defense should improve with experience, reaction times, reflexes, the "phyiscal" side of defense makes it more difficult to get to the ball. In theory, Castro will hit his defensive prime next year and decline after that. He will start to lose the ability to get to the fringy balls that account for most of his errors right now that makes him a plus defender without the mental side.

Defense definitely declines with age, but I think you are way off when saying that a guy is a better defender at 22 or 23 than he will be a 28 and 29, which is the physical peak for most professional athletes. I haven't done a lot of research, but most of the players I remember were at their best defensively in their late 20's.

Here's a study...includes this line:
"Based on this study, the defensive peak for a shortstop is between the ages of 22 and 24. Afterwards, for the matched pair at every age level, the shortstops showed a decline. The average decline is nine plays per year, which roughly corresponds to seven runs per year."
-
http://www.hardballtimes.com/main/article/fielding-aging-curves/

[NormB]

We could play the "let's find examples" game all day. Very few stats have a guy being one of the best in the game one year to being one of the worst in the game the next year with the kind of regularity you see it in UZR.

And, again, I say: "it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching." The fact that there are wild swings in offensive performance or pitching doesn't disprove my theory - it actually supports it.

Does anyone really want to dispute that?

I guess I don't really know what is considered a big swing in UZR numbers. is -3 one year to +3 the next year a big swing? Or is it a small swing? How many missed plays does one have to have to create that change?
My impression is that -3 to +3 isn't that big of a swing, but maybe I'm wrong.

[hansman1982]

We could play the "let's find examples" game all day. Very few stats have a guy being one of the best in the game one year to being one of the worst in the game the next year with the kind of regularity you see it in UZR. And, again, I say: "it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching." The fact that there are wild swings in offensive performance or pitching doesn't disprove my theory - it actually supports it. Does anyone really want to dispute that?

I guess I don't really know what is considered a big swing in UZR numbers. is -3 one year to +3 the next year a big swing? Or is it a small swing? How many missed plays does one have to have to create that change? My impression is that -3 to +3 isn't that big of a swing, but maybe I'm wrong.

http://www.fangraphs...hp/defense/uzr/

There is the fangraphs article on UZR. The thing I didn't know is that UZR is a counting stat so that will skew player stats even further for the ones that play every day. In this article it states that the best defender in 2010 was Brett Gardner at 22.3 UZR and the worst was Matt Kemp at -24 UZR. With that in mind, is a 6 UZR swing that wild? Basically, Castro went from the 35th percentile to the 20th percentile.

Byrd is an interesting case example as a couple times in his career he has swung from negative teens to positive teens. However, the article does state that sample size is an issue with UZR and you should always seek out 3 years of data.

The problem with any defensive statistic is that it is heavily weighted on human eyes. Where did the ball land, how hard was it hit, how quickly the player got the ball back in to the infield, etc… As such, there will never be a perfect defensive stat.

What would be interesting is to take the UZR rankings for the entire year of 2011 and compare them to a 3- and 5-year average of UZR to determine any how much it varies to see if there are any patterns. Maybe players new to a stadium receive a big bump, maybe players in a contract year always do wildly better, etc...

[hansman1982]

Why is it troubling that there is so much variation in year to year defense? We see the same year to year fluctuations in pitching and hitting.

Starlin Castro's UZR dropped from -2.7 to -8.7 from 2010 to 2011. He committed 2 more errors last year in 300 more innings, there is no way his defense got that much worse. Tell me where that much variation came from.

Yeah, there's fluctuation in hitting and pitching, but nothing like the kind of swing I pointed out in Byrd (which is commonplace in UZR). Further, it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching.

Jacoby Ellsbury Hr's. Adam Dunn's OPS James Shields ERA Those swings aren't as big as the UZR jumps? I'm no UZR supporter by any means, but I think they jump around just as much as a players AVG, a players HR's, a players RBI's, ERA, Whip, etc....

We could play the "let's find examples" game all day. Very few stats have a guy being one of the best in the game one year to being one of the worst in the game the next year with the kind of regularity you see it in UZR. And, again, I say: "it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching." The fact that there are wild swings in offensive performance or pitching doesn't disprove my theory - it actually supports it. Does anyone really want to dispute that?

I will dispute that. While the talent may not change drastically, the product on the field will, just the same as with pitching and offensive stats and sometimes, for no real good reason.

Same as with writing posts to this site, sometimes, despite the effort and preparation, you have articles that are just really good as opposed to stupendous. It is just a fact of life.

[King Jeff]

The problem is that defense isn't supposed to jump around that much. If anything, defense should improve with age. Also, from what I've seen, the stats don't justify the UZR jumps and drops, which is why it confuses me.

Actually, defense is the first thing to decline even before speed, while decision making on defense should improve with experience, reaction times, reflexes, the "phyiscal" side of defense makes it more difficult to get to the ball. In theory, Castro will hit his defensive prime next year and decline after that. He will start to lose the ability to get to the fringy balls that account for most of his errors right now that makes him a plus defender without the mental side.

Defense definitely declines with age, but I think you are way off when saying that a guy is a better defender at 22 or 23 than he will be a 28 and 29, which is the physical peak for most professional athletes. I haven't done a lot of research, but most of the players I remember were at their best defensively in their late 20's.

Here's a study...includes this line:
"Based on this study, the defensive peak for a shortstop is between the ages of 22 and 24. Afterwards, for the matched pair at every age level, the shortstops showed a decline. The average decline is nine plays per year, which roughly corresponds to seven runs per year."
-
http://www.hardballt...g-aging-curves/

Cal Ripken had his three best defensive years at ages 28,29, and 30. Then I looked at Derek Jeter, and his best seasons were his late 20's and early 30's. I know it's a small sample size, but two of the best shortstops ever completely ignore the aging curves theory. Besides, those ratings depend largely on balls in play and balls handled, which are almost completely out of a players hand aside from positioning. They don't take into account ballpark differences, whether teams are full of ground ball or fly ball pitchers, who their defensive teammates were.

[wvcubsfan]

We could play the "let's find examples" game all day. Very few stats have a guy being one of the best in the game one year to being one of the worst in the game the next year with the kind of regularity you see it in UZR. And, again, I say: "it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching." The fact that there are wild swings in offensive performance or pitching doesn't disprove my theory - it actually supports it. Does anyone really want to dispute that?

I guess I don't really know what is considered a big swing in UZR numbers. is -3 one year to +3 the next year a big swing? Or is it a small swing? How many missed plays does one have to have to create that change? My impression is that -3 to +3 isn't that big of a swing, but maybe I'm wrong.

http://www.fangraphs...hp/defense/uzr/

There is the fangraphs article on UZR. The thing I didn't know is that UZR is a counting stat so that will skew player stats even further for the ones that play every day. In this article it states that the best defender in 2010 was Brett Gardner at 22.3 UZR and the worst was Matt Kemp at -24 UZR. With that in mind, is a 6 UZR swing that wild? Basically, Castro went from the 35th percentile to the 20th percentile.

Byrd is an interesting case example as a couple times in his career he has swung from negative teens to positive teens. However, the article does state that sample size is an issue with UZR and you should always seek out 3 years of data.

The problem with any defensive statistic is that it is heavily weighted on human eyes. Where did the ball land, how hard was it hit, how quickly the player got the ball back in to the infield, etc… As such, there will never be a perfect defensive stat.

What would be interesting is to take the UZR rankings for the entire year of 2011 and compare them to a 3- and 5-year average of UZR to determine any how much it varies to see if there are any patterns. Maybe players new to a stadium receive a big bump, maybe players in a contract year always do wildly better, etc...

I just read that and the UZR primer and now my head hurts, I'm more confused than 15 minutes ago, and I'm almost positive that this stat is worthless. Oh, well what am I supposed to believe, UZR or my lying eyes?

[Brett]

We could play the "let's find examples" game all day. Very few stats have a guy being one of the best in the game one year to being one of the worst in the game the next year with the kind of regularity you see it in UZR. And, again, I say: "it's just my opinion from playing and watching baseball that defensive ability is likely to be more consistent from year to year than hitting or pitching." The fact that there are wild swings in offensive performance or pitching doesn't disprove my theory - it actually supports it. Does anyone really want to dispute that?

I guess I don't really know what is considered a big swing in UZR numbers. is -3 one year to +3 the next year a big swing? Or is it a small swing? How many missed plays does one have to have to create that change? My impression is that -3 to +3 isn't that big of a swing, but maybe I'm wrong.

http://www.fangraphs...hp/defense/uzr/

There is the fangraphs article on UZR. The thing I didn't know is that UZR is a counting stat so that will skew player stats even further for the ones that play every day. In this article it states that the best defender in 2010 was Brett Gardner at 22.3 UZR and the worst was Matt Kemp at -24 UZR. With that in mind, is a 6 UZR swing that wild? Basically, Castro went from the 35th percentile to the 20th percentile.

Byrd is an interesting case example as a couple times in his career he has swung from negative teens to positive teens. However, the article does state that sample size is an issue with UZR and you should always seek out 3 years of data.

The problem with any defensive statistic is that it is heavily weighted on human eyes. Where did the ball land, how hard was it hit, how quickly the player got the ball back in to the infield, etc… As such, there will never be a perfect defensive stat.

What would be interesting is to take the UZR rankings for the entire year of 2011 and compare them to a 3- and 5-year average of UZR to determine any how much it varies to see if there are any patterns. Maybe players new to a stadium receive a big bump, maybe players in a contract year always do wildly better, etc...

I just read that and the UZR primer and now my head hurts, I'm more confused than 15 minutes ago, and I'm almost positive that this stat is worthless. Oh, well what am I supposed to believe, UZR or my lying eyes?

You can't hide your lyin' eyes.