From: mjones@fenway.aix.kingston.ibm.com (Mike Jones)
Subject: Re: Lies, Damn Lies, & Statistics (was Re: The Monthly Cecil Fielder Thread
Date: Fri, 04 Sep 92 23:44:27 GMT
Reply-To: mjones@donald.aix.kingston.ibm.com
Organization: IBM Corp. Kingston NY

In article <1992Sep04.193158.7434@brtph560.bnr.ca> psycho@brtpa25.bnr.ca (Paul Jezioranski) writes:
>In article <1992Sep04.162411.49348@watson.ibm.com>,
>mjones@fenway.aix.kingston.ibm.com (Mike Jones) writes:
>> In article <1992Sep03.105123.10657@brtph560.bnr.ca>
>psycho@brtpa25.bnr.ca (Paul Jezioranski) writes:
>> >Sure. Simply idiotic. An example:
>> >
>> >	Rudy Fafoofnik: 680 Plate appearances, 1.000 SLG, 1.000 OBP
>> >	
>> >......	but he scored zero runs because he hit 680 two out singles and
>the guy
>> >	behind him struck out 680 times.
>> 
>> BAG O' MF. Let's ignore, for the moment, that you've chosen an example that
>> will NEVER, NEVER, NEVER, occur in anything resembling real life (even if
>> the aliens from the planet Zartron come back and run the season again, like
>> in 1987). 
>
>Really; gee, I thought it was pretty realistic.
>
>> Look, instead, at what Rudy did. How valuable was Rudy? Well, for
>> starters, look at how stupid his manager was. If he batted every time with
>> two out, then it's obvious that his manager didn't put that 1.000 OBP
>> leadoff, which leads one to suspect that he must have been playing for Don
>> Zimmer. It's not his fault there was two out every time he batted. It's not
>> his fault that the man behind him struck out. 
>
>Agreed.

Good start.
 
>> Put Rudy in front of, say,
>> Cecil Fielder and Mickey Tettleton and watch him score about 200 runs and
>> each of them get boatloads of RBI.
>
>Assuming he performs identically in his new spot in the batting order.
>Assuming all other factors are essentially the same, but they won't
>necessarily be, will they? Zartron could block the sun, too...

That's exactly the point. I want to look at what Rudy might have done in
terms of stats some people claim are valuable if he had performed exactly
the same in a different situation, in order to show that those stats are
highly situation-dependent. I'm not claiming that IF you put Rudy in front
of Cecil and Mickey, THEN he would score 200 runs, but rather that IF Rudy
had performed exactly as he did with average performances from Cecil and
Mickey behind him, THEN his performance (as measured by Runs) would have
been very different - WITHOUT HIS HAVING DONE ANYTHING DIFFERENT. Do you see
the difference between the two claims?
 
>> Now tell me. If we're trying to figure how valuable Rudy is, should we
>> deduct from his value for the men who made outs in front of him? Should we
>> deduct for the men who made outs behind him? More to the point, if Rudy
>> repeats the same statistics the next year but his team has traded for Brett
>> Butler and Rickey Henderson to hit in front of him and Juan Gonzalez and
>> Mark McGwire to bat behind him, his RBI and R will balloon.
>
>Notice you say *if* Rudy repeats his feat. You can have all the
>potential in the world, but potential doesn't mean squat in the standings.

Irrelevant, for two reasons. First, either statistics have some predictive
value or not. If they don't, they're meaningless and we should give the
batting crown to the guy with the prettiest swing. Second, The hypothetical
took Rudy's repeating (or close) as the presumption. The question is whether
his value increases due to what the players around him do. I'm sure that
you'll have to agree that the odds of him having two seasons as you
described is only infinitessimally larger than the odds of him having one of
them.
 
>> Does this
>> reflect an increase in *his* value?
>
>Maybe. 

Please do explain. This is the crux of the argument, and I'm afraid I don't
find "maybe" to be a particularly enlightening answer.

>> >contention is that adding external dependencies (such as who and how
>> >many were in scoring position, who was pitching, etc) only complicates
>> >things and leads people to draw errant conclusions like "if Jose was in
>> >his place, he'd have 5000 RBI". But I guess that's most of the
>> >attraction of all these stats. 
>> 
>> Exactly. That's why true SDCN's prefer stats that eliminate or control for
>> as many of those other conditions as possible. RBI are *bad* measures of
>> individual ability exactly because they're so context dependent. Several
>> studies have shown that two factors determine a player's RBI totals: his SLG
>> and the number of men on base when he bats. A player has control over
>> exactly one of these things. Hint: it's not men on base.
>
>I'll concede that RBI are a bad measure of individual ability, but they
>still measure his opportunism, which is a big part of the game. Also,

Actually, they don't even measure that very well unless you normalize for
RBI opportunities. Even Babe Ruth would never have had more than 60 RBI if
he'd never had anyone on base in front of him. Anytime you count by pure
RBI, you're rewarding primarily players who get a lot of at bats with people
on base.

>singles, doubles, etc. have a huge element of opportunism because poor
>pitching can heavily dictate the size of these numbers (as can position
>in the batting order, time of day the game is played, ballpark etc.). So
>all the stats become context dependent. 

A huge element? Do you have any evidence to support this claim? What would
provide any sort of systematic bias that would allow you to say that, for
instance, Wade Boggs has faced easier pitching over his career than, say
Omar Vizquel? And what has reversed the situation this year? Generally, we
assume that players face about the same strength of pitching over the course
of a season. We do this because a) there's not that much difference between
the best and worst staffs in the league, b) everybody plays the same amount
of games (modulo divisional differences) against the same other teams, and
c) pitchers don't move between teams very often. You're basically claiming
(by saying that all offensive stats are context dependent) that the
opposing pitching staff effect is significant. Why?

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

The US should stand up for values, shared values. Why are we more shocked
when a dozen people are killed in Vilnius than a massacre in Burundi? Because
they are white people. That's who we are. That's where America comes from.
	- Pat Buchanan, in the London Sunday Telegraph
Newsgroups: rec.sport.baseball