From: snichols@adobe.com (Sherri Nichols)
Subject: Re: More fuel for the Stats fire
Organization: Adobe Systems Incorporated
Date: Tue, 21 Jul 1992 15:56:11 GMT

In article <54615@mentor.cc.purdue.edu> poutsmaj@mace.cc.purdue.edu (unknown) writes:
>in terms of mathematics.  Apparantly this is the motto of many of the netters
>here as they try to reduce all of a baseball player's talents into one,
>easily understandable parameter (ave, obp, ops, rc, etc).

That's certainly not my goal; my goal is to use statistics to better
understand how the game works.  

>  It is always
>important to keep in mind, however, that statistics only reflect what a
>player has done and not what he will do (or is capable of doing).

That simply isn't true.  There is a positive correlation for most of the
offensive stats from year to year for a given player.  For some of the
stats, the correlation is quite good; like for walks per plate appearance.
For others, it's not as good, though still positive; like for batting
average, which is why a lot of us don't like to use batting average when
evaluating a player.

>  A classic
>example of this is Kirby Puckett.  When Kirby first came into the league
>in 1984, he was an opposite field-singles hitter.  His batting average was
>about .280 and his obp and slg were not much better.  Therefore, if I would 
>that KP would hit 30 HR and bat over .330, everyone would have thought I was
>crazy.  I would have probably heard a bunch of numbers supporting the
>conclusion that KP was a mediocre player at best and lacked the power to
>hit many HR's.

Or probably not.  You see, most of us wouldn't try to evaluate Puckett
based on one partial season of major league experience (in which he batted
.296, btw, not .280 - big difference), but would have also looked at his
minor league numbers, where he posted batting averages above .300 most of
the time, and showed good doubles power, and some home run power.  Players
with good doubles power tend to convert more of that power into home run
power as they get older.  Puckett further benefitted from whatever effect
was causing an increase in power across the board in '87, and to a lesser
extent, in '86.

>  Obviously the problem is that the stats could not account
>for the adjustment the Kirby made in his swing, changing from his singles
>hitter approach to a 'drive the ball' mentality which has been so successful
>for him.  The point here is that, even though Puckett was equally as talented
>before 1987, the numbers did not show it.  This is a serious problem with
>statistics:  they don't really show player potential.  

Only if you don't understand how to look for it.

>Therefore, when I see questions like "Who would want Wade Boggs?", all I 
>can think is "Who wouldn't?"  Sure this year is a down year for him (so far)
>but his numbers in the first half in no way predict what he will do in the
>second. 

However, there are a couple of well-understood effects conspiring against
Wade Boggs.  One is the effect of age; Boggs is 34, and will probably be
looking for a long-term contract.  At 34, he should still be capable of
having great seasons, but they won't happen as often, he'll be more prone
to injury, will take longer to recover, etc.  These effects will get worse
as he gets older.  Look at George Brett the last few years.  He's had one
great season, surrounded by good to mediocre seasons.  

The other effect which should give anyone interested in pursuing Boggs
(other than Boston) is the home park effect.  Boggs throughout his career
has enjoyed a substantial boost in his numbers from playing half his games
in Fenway Park.  While overall he hit .332/.421/.460 last year, on the road
he hit .282/.368/.350.  Not all that impressive.

>The fact that stats can't predict what will happen in the future is why
>teams have scouts and coaches to evalute players' talents.  True it is
>a subjective practice, but it is the only way it can really be done.

Teams also use statistics to evaluate players.  Some of them do a better
job at using stats than others, but they don't ignore them.

Sherri Nichols
snichols@adobe.com