From: mjones@fenway.aix.kingston.ibm.com (Mike Jones)
Subject: Re: Mattingly, what a fine fielder (was: Hardly not etc.)
Date: Fri, 06 Nov 92 18:06:55 GMT
Distribution: na
Reply-To: mjones@donald.aix.kingston.ibm.com
Organization: IBM Corp. Kingston NY

In article <7936@transfer.stratus.com> gene@bogus.sw.stratus.com (Eugene Loparco) writes:
>In article <7911@transfer.stratus.com> jmann@vineland.pubs.stratus.com writes:
>>In article <1992Nov05.005627.159157@zeus.calpoly.edu>  
>>
>>More to the point though, are all "feelings" created equal?
>>(I'm not sure why you empahsized "feels," by the way.)  I've 
>>seen Luis Rivera have some real good games at shortstop. (He's
>>also had some real bad ones there, but I'll ignore those for
>>now.)  Is it reasonable based on that to say that I feel that
>>Luis Rivera is as good as Ozzie Smith?  Or, lets take a
>
>I think Mr. Lee's point (and mine) is that if you want to think that
>Luis Rivera is as good as Ozzie Smith defensively that is your opinion
>and you are entitled to it.

True, you are entitled to it. On the other hand, anyone else is entitled to
feel that you are wrong, and to argue the point. Look, when you say that you
know, or think, or feel, that player X is as good (in some sense) as player
Y, you're making a value judgement. There are better and worse ways to do
this, and they can be determined (more or less) objectively. If I say that I
think John Olerud is the best hitter in the history of baseball because he
has a gorgeous swing (which he does), that's an opinion. Is it a correct, or
even defensible opinion? Nope. It can be debated on its merits (or lack
thereof). Now, if I say that John Olerud is my favorite player, that's not
objective and I don't expect any flak about it.

Take Tony Pena, for example.  As a diehard Red Sox fan, I am torn over
Tony. I love to watch him, and I *think*, though I admit to having no
evidence, that he helps the pitching staff pitch better. I have no qualms
about saying that I like him, and I like to watch him. On the other hand, I
have no evidence whatsoever that he helps the team defensively, and a lot of
evidence that he hurts the team at the plate. I can't, in good concience,
say that I think Tony is a good catcher (though he used to be). 

>I personally felt that Alvaro Espinoza was an exceptional fielder, in
>fact one of the best in baseball, just by seeing him play.  I was flamed
>to charcoal for that statement, but I defended myself by saying it was
>MY opinion and not fact.

Your statement was almost certainly perceived as saying that it was your
opinion that the fact "Alvaro Espinoza is an exceptional fielder" was true.
There are a lot of posters here who are very interested in baseball, and who
want to know what is true about it. Those are exactly the people who will
question (and, it must be admitted, sometimes none too gently) these
statements, because they want to know how you know that. They're as
interested in knowing when they're wrong as when they're right. On the other
hand, baseball is a vast repository of "conventional wisdom", a large part
of which is just plain wrong. Most of the statheads, I think, look forward
to a day when the statement "you can't judge defense except by direct
observation" is as obviously false as "curve balls don't really curve".

>>recent example: Borders had a great world series. Is it
>>reasonable for me to say that I feel he is as good a hitter
>>as Barry Bonds? He certainly was good in those games
>>I watched.  
>>
>>You have to judge players based on a reasonable number of games.
>>A dozen isn't enough. The only way to do this is stats. (Oh,
>
>I disagree.  According to some people on the net the "stats" prove that
>Don Mattingly and Andy Van Slyke are mediocre (at best) fielders.  If you
>talk to the people who see them all year (namely the players and managers)
>you will find that this is simply not the case.

Try an experiment. For a month or so, every time you see the word "stats",
think "systematic recorded observations by a number of people". That's what
statistics really are, after all. Most of the direct observations we hear
about are flawed in one way or another. Jim Leyland gets to see AVS every
day, and probably has a fairly good feeling for his defensive capabilities.
On the other hand, if he claims AVS is one of the best, he's also making a
judgement about Otis Nixon, Brett Butler, and a bunch of other players whom
he does *not* see very often, and even then in a very limited range of
conditions. 

>>you can go to all your team's games and say that you think
>>one of their players is good and make a reasonable case for
>>it, but you still can't do an effective job comparing him
>>to another play, who you've only seen ten times or less.)
>>
>>I've found this (and previous debates) on defense to be rather
>>interesting, because it is the last place in baseball where
>>many baseball people still try to judge the "best at XXX" just by 
>>watching them, not by any coherent statistical basis. We may
>>debate which stats make someone the "best power hitter" or
>>"best hitter"  (OPS vs. BA vs. SLG vs. OBP vs. all sorts of
>>other things). But on defenese for too long it's come down
>>to "I watched him and he looked good."  I'll be interested 
>>to see if baseball as a whole (and not just isolated pockets
>>of stat fans) adopt some kind of better defensive stat in the
>>near future.
>
>I don't think there is a defensive stat that can accurately measure a
>player's performance...

OK, here's a line of reasoning about *why* I think DA does a pretty good
(not perfect) job of measuring a player's defensive performance (except for
catchters and, to a lesser extent, first basemen). I'd like to get some
discussion about exactly what is wrong with it.

1. The basic job of a team on defense is to turn batted balls into outs.
2. Teams divide the field into "zones" and position players to cover those
  zones. We typically know them as "left field", "shortstop", etc.
3. The basic job of a player on defense is to turn batted balls that enter
  his area into outs.
4. We assume that the distribution of batted balls around the field is
  roughly constant from team to team.
5. Defensive Average divides the field into zones, and systematically
  records how many balls are hit into each zone, and what the outcome of the
  play is. It ignores "errors" and other official scoring. It ignores
  positioning (more accurately, if there is a true effect due to a player
  knowing where to position himself, it will give that player credit for
  the balls he gets to due to that ability). It does not distinguish between
  "errors" and balls not gotten to, on the grounds that the outcome is the
  same relative to item 1.
6. Defensive Average gives a fielder "extra credit" for balls gotten to
  outside of his zone.
7. Defensive Average does not take throwing ability into account, except
  as it results directly in outs.

Comments? Obviously, I'm interested in convincing people that DA is a good
measure. On the other hand, if it has basic flaws, I'd like to stop making a
fool of myself by recommending it.

   Mike Jones  |  AIX/ESA Development  |  mjones@donald.aix.kingston.ibm.com

Luis Tiant comes from everywhere except between his legs.
	- Curt Gowdy
Newsgroups: rec.sport.baseball