From: dtate+@pitt.edu (David M Tate)
Newsgroups: rec.sport.baseball
Subject: Re: RP/PA for AL and NL (More bogus RP stats)
Date: 22 Jul 92 03:22:21 GMT
Organization: Factors of Ys, Inc.

In article <Brr616.wI@undergrad.math.waterloo.edu> djohnson@cayley.waterloo.edu (David "Clearly not a Dave" Johnson) writes:

(Dr. Dave and David Johnson go back and forth, to wit:)

>>>This stat shows the players value to the team.  
>>
>>I heard you the first time.  I just don't see how you reached this odd
>>conclusion.  Or do you have some weird definition of "value" that you
>>aren't sharing with me?
>
>What you don't think that a player who has more RBI and Runs than anyone
>else on the team isn't valuable.  

And you (below) complain about me putting words in *your* mouth?  Please.

You just claimed that "[RP/team runs] shows the player[']s value to the team."
I ask you why you think this, and you ask me something about "Isn't a player
with more runs and RBIs than anyone else on the team valuable?".  I thought
this was supposed to be a ranking system.  Let's stick to the original claim,
shall we?

Junior Felix leads the Angels in R+RBI, with about 80.  Does this make him
"valuable"?  No.  He's the ninth or tenth best CF in the American League, at
best.  He just happens to play for a team that couldn't compete in AAA this
year.

>A guy with a lot of RBI and Runs scored
>for their team as compared to other players shows that that player has been 
>more productive in the opportunities he has got than other players on his
>team.

How's that, Gracie?

Apparently you are under the mistaken impression that somebody hands out
RBI and run-scoring opportunities to players, being careful to make sure that
everyone gets exactly the same number.  It doesn't work that way.  On any one
team, there can be a 100% or more variation from player to player in RBI
opportunities.

>>>but dividing it by the teams total
>>>runs this factors in the whole teams inability to drive in runs.  
>>
>>No, what it does is tell you approximately where Joe Carter ranks among
>>Angels players in terms of being awarded RBIs.  It *prevents* you from
>>making any comparison with players on other teams, since the context of
>>playing on the Angels has nothing in common with, say, the context of
>>playing for the Blue Jays.
>
>But this stat will show the ability of Carter to drive in runs when he
>gets a chance to.  

Not at all.  You haven't done anything at all that comes close to counting
opportunities to drive runs in.  The are *not* evenly spread across the team.

>California scores less runs because they get less
>opportunities to do so 

No, because they *cause* less opportunities.  There is no lottery you can
enter to win RBI opportunities.

>thus Carter as an individual player will have less
>opportunities as well 

This doesn't follow.  It depends greatly on where he bats in the order, and
who the players around him are.

>and thus his RBI and Run total will go down.  This
>value I find with this stat as compared to others is that it doesn't
>depend as much on the players who hit in front and behind him as some stats
>do.

You get rid of the immediate dependency by making it depend on something even
*less* relevant, namely the entire rest of the team.

>>What fraction of the '27 Yankees' runs did Babe Ruth drive in?  Compare that
>>with Nate Colbert on the Padres of the early '70s.  Was Nate Colbert more
>>valuable than Babe Ruth?

I notice you didn't answer any of these questions...

>A good player should get some Credit and not be brought down just because
>he has poor teammates.  We are trying to evaluate a player fairly not
>make him look bad because he has bad teammates.

Not trying to make him look *good* because he has bad teammates, either.
How about just evaluating him based on those things his teammates don't
affect?  Is that too radical a notion?

>>The point is not that it makes him a worse player; the point is that it
>>makes him *the same* player, whichever team you put him on.  Regardless of
>>the RBI and R totals that his team makes out of him.
>
>But isn't that what we want when comparing players.  

Yes!  But it isn't what you've done.

>How would he do on an
>average team rather than a good team or a poor team.  

It's called an MLV, and you can figure it from individual and league batting
stats.  Hint: it has nothing to do with Runs Scored or RBIs...

>The problem with
>RBI and RUNS is that it depends too much on what the players are hitting 
>around him are doing.  

EXACTLY!  And you can't fix that by adding yet another dependency on still
more players who aren't the one you're trying to evaluate.

>In my example i made Carter the *same* player on
>different teams and giving Carter the same rating on whatever team he
>plays on is the best thing about this stat.  

In no way did you make Carter "the same player on different teams" with this
normalization.  There's an obvious test: put the same player on two teams,
and see if your normalized stat gives him the same rating on both teams.  It
won't.  I guarantee it.

>Carter should be just as
>good of a player on California as Toronto it is just that he will be less
>productive because he gets less opportunities.

Argh.  I wish you wouldn't use the word "productive" that way.

Yes, Carter will be Carter whether he plays for Toronto or California.  So
why use a stat which pretends that he suddenly got better just by moving to
California?  Which is what you're advocating...


-- 
       David Tate        |"Out of the dugout endlessly swinging,
 dtate@unix.cis.pitt.edu | Out of the manager's throat, the sound fundamentals,
 Prof. of Story Problems | Out of the six-month season..."            
 Member ORSA, TIMS, SABR | 	Walt "Lefty" Whitman