From: tedward@cs.cornell.edu (Edward [Ted] Fischer)
Subject: Re: Value of Stats
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Tue, 28 Jul 1992 20:32:20 GMT

In article <1992Jul28.192601.10342@ramsey.cs.laurentian.ca> 91287041@ramsey.cs.laurentian.ca (roger maynard) writes:
>
>It would tell us what percentage of a division-winning offence Bonds is
>repsonsible for.  Likewise Puckett.  It would tell us who carried the 
>biggest load, that is, it could be a measure of MVP.

How about the pitching, then?  Or is pitching irrelevant?  It's fine
to say "Carter was worth 20% of a division-winning offense".  But was
that team shaped like the Tigers or like the Dodgers?  Did they win
games by bludgeoning opposing pitchers or by being miserly with the
runs allowed?

>And forget about 
>guys like Griffey playing for bad teams.

Okay.  But I'm talking division-winners here.  Division-winning
offenses still range from great to average.

>How would you make such a calculation?

I would take the fraction MLV/(team runs - league average runs).
Assuming I wanted to take such a measure at all...

>ok then what percentage of total LEAGUE production did the three players make?
>This business of saying so many runs above average is skirting the issue. 
>What was the average?  Lets add that in and then compare the three.

You need some baseline.  Some sensible baselines are:
1) A player who strikes out every time up.
2) Replacement level player.
3) Best player in the league that year.
4) League average player.

Now the first is just too weird.  We have tools which work for players
in the normal range of abilities.  But we would need an entirely
different method to estimate how many runs a major league team would
produce with a little-leaguer batting in the lineup.  The second is a
reasonable baseline, but it is difficult to pin down.  Exactly how
poorly does a replacement level player hit?  The third would be
strange.  If one player hit 50 HR in a season but somebody else hit
51, is the first player really less valuable than the guy who led the
league the next year with 39?  It would be fine for comparisons within
one season, but would have no continuity from one year to the next.

Leaving the fourth.  Which isn't quite what we want.  After all, even
a league-average player has some value to his team.  If he gets
injured, his replacement probably won't hit nearly as well.  But since
wins are *roughly* linear to offense, the linear transformation from
replacement-level to league-average won't mess things up too much.

Bonds was worth something like 50 runs-above-average last year, and
Puckett was worth something like 25 runs-above-average.  This doesn't
mean that Bonds was twice as valuable as Puckett.  The baseline isn't
appropriate for that.  In reality, Bonds was worth 50+x over
replacement, and Puckett was worth 25+x over replacement.  But 50-25 =
(50+x) - (25+x) = 25 runs.  And 25 runs ~ 2.5 wins.  And so you these
numbers do have some meaning.  The claim is that the Pirates last year
would have expected to win 2.5 fewer games with Puckett's bat than
with Bonds' bat.

>>Roughly double.
>
>Double?  You say further down that there were only 18 or 20 players better
>than Puckett in the AL.  Salazar is almost dead-on average by your reckoning.
>Does this mean that there are only 54-60 players better than average in the 
>AL assuming AL average is approximately the same as NL?

Roughly speaking, yes.  There aren't more than 120 AL players with
comparable playing time.  And because of the pyramid distribution of
talent, there should be fewer players above average than below.  Perhaps
Salazar is underrated?  Or perhaps somebody forgot to park-adjust their
stats.  :-)

>The 18th or 20th could become #1.  And many teams don't even have a player
>of that calibre.  Salazar's are a dime a dozen.  The fact that ordinal ranking
>is not important works against your argument.

Salazar is better than a dime a dozen!  At least last year he was.

>Yes but it might be enlightening to find out what Minny's chances would have
>been without Puckett and likewise for Bonds, Carter and Gant.

A suggested method is to take the difference between Puckett and his
replacement (probably Larkin/Bush), translate that into runs, divide
by 10 to get wins, and subtract from their actual record.  I'm not
sure why you want to do this, though.  If a team wins by 1 game, the
loss of any good player on the team would have cost them the division.
Does this mean that all of those players are more deserving of the MVP
than any of the players on a team that blew away the division by 20
games?

Cheers,
-Valentine
-- 
If Plantier goes, I go!				tedward@cs.cornell.edu
Newsgroups: rec.sport.baseball