From: mjw@Xenon.Stanford.EDU (Michael Wolverton)
Subject: Re: Cecil signs :-( :-( :-(
Organization: Computer Science Department, Stanford University.
Date: Wed, 27 Jan 1993 00:42:44 GMT

In article <2531@blue.cis.pitt.edu> genetic+@pitt.edu (David M. Tate) writes:
>[Explanation of his views on league average]
>Is this more clear?

Yes. In reading this post, it suddenly dawned on me what the cause of our
different views is (well, maybe): your viewing baseball as a zero-sum
game. You certainly *can* view it that way; if you see each "win" as
(say) a dollar won and each "loss" as a dollar lost, then it is clear
that a team which plays above .500 is "positive" and a team which plays
below is "negative". But, of course, that's not the way it works. Wins
and losses aren't dollars, and finishing a few games below .500 isn't
really "negative" any more than finishing a few games above .500 is. For
the purposes of *this* discussion, a more valid way of viewing baseball
is as a game where *everybody* wins -- some just win more than others.

My turn for an analogy: poker is clearly a zero-sum game.  If you 
consistently lose money at it, then your poker-playing skills have 
negative value to you.  But that's only because you have an option -- 
namely, not playing -- which costs you nothing.  That option makes poker 
a poor analogy to baseball.  Now consider that you're the owner/GM of a 
"poker franchise".  You only get to put one player into the game, but you 
also retain the rights of several poker players in your farm system.  
Quitting the game is not an option -- you've made a contractual agreement 
with the other poker franchises that you'll play out a full season.  
You're an expansion franchise, though, so your present prospects don't 
look so hot.  Your #1 player is definitely below average.  He hasn't 
gotten the hang of cheating yet, so he loses over the long haul, but he 
plays pretty conservatively so he never loses all that much.  But your 
farm system consists only of a bunch of brain-dead Stanford grad students 
who consistently bet big and then try to bluff when they have "Queen 
high".  You'll lose big if one of these lame-o's gets in the game.  
Wouldn't you agree that your #1 guy has value?  Or "contribution", or 
whatever you want to call it?  He's saving you a ton of money!  And 
this is true whether you look at it prospectively (he will save you money 
in the future) or retrospectively (he saved you money in the past) -- 
doesn't matter.  You can still view the poker game as a zero-sum game, I 
suppose, but it really is counter-productive to look at it this way from 
the standpoint of evaluating your individual players.  Suppose that you 
get the gate receipts from these poker games which are guaranteed to 
cover the maximum possible losses in a game.  Then any money your #1 guy 
makes you (which the Stanford idiots would've lost) is pure profit for 
you.  That's his value (or contribution, or whatever), even though he's 
below average in this "zero-sum game".

(I should say here that, even if you *do* view baseball as a zero-sum 
game, where above .500 is "positive" and below .500 is "negative", you 
*still* want to use replacement level to evaluate your players.  A 
below-average player can still bring you from below .500 to above .500 if 
he's replacing someone really bad.  I just hope that, by showing that 
baseball can be viewed equally well as a positive sum game, it would 
become clear that replacement level is the way to go.)

>So, for example, the answer to "How can you say that a 12-12 pitcher with
>200 innings is 'worthless'" is (a) that's an above-average performance, I'll
>bet; 

Pitching 200 innings at .500 and league-average ERA is above-average? Why
do you say that? I'll tell you why I might say that: because if you
compared everyone to replacement level, Joe Average's value would be
higher than the average value for all pitchers, or all starters, or even
all starters with 10+ starts. Most of the guys with lower ERAs would have
far fewer innings than Joe, enough fewer that Joe's 200 innings (taking 
away innings from the Joe Slusarski's of the world) would be more 
valuable than their 120 or 150.

>(b) not 'worthless' but 'win-neutral', which is different,

Not from what I can see.  You make it clear in (c) that you don't think 
this guy had any value (after he's finished).  That, to me, is the same 
as saying he is (or was) "worthless".

>(c) because the ability to pitch lots of innings has prospective value (as a
>hedge against having to use a worse pitcher), but no *retrospective* value
>beyond the quality of those innings.

This doesn't make any sense to me.  We sign an average pitcher 
because we think he'll improve the team, help us get to the playoffs, 
etc. (i.e., he has prospective value), but when he actually goes out and 
*accomplishes* these things, we retrospectively decide that he was 
worthless?  Value is value, whether your projecting it for the future or 
looking back on it.  If a guy has value because he *will* improve your 
team, then he certainly has value (or had it) if he *did* improve your 
team.

-Michael
-- 
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Michael Wolverton                       "Is that clear?"
mjw@cs.stanford.edu                     "No, but it's consistent!"
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