07 May 2013

Wins are an Imperfect Way to Measure Who is Best

Bill Parcells once uttered these words which have become a silly mantra.
You are what your record says you are.
Why is this silly?  I think there is a kernel of truth in Parcells statement.  Our current state is a product of what we have done, so in a way we are what we were.  However, this is a statement that is fraught with potential error.  What if the way in which we define ourselves and others is an imperfect way of defining ourselves and others?  What if what we use to measure does not translate accurately what we are?  Is your record truly defining you.

We know that any statistic in baseball, wins included, is an approximation of ability.  You truly are not measuring ability, you are measuring the impact of ability.  Stats are the imprint of the hand, not the hand.  That imprint can have errors.  This is a known fact.  OK, maybe some do not know this to be true as I somehow spent much of Monday discussing why statistics are not perfect definitions of ability.

Maybe a picture will help.
Converting Performance into Wins

What we have in the above diagram are really three components: ability, fortune, and result.  Ability is the grey circle full of components that make up how well a team will perform.  Fortune is represented by a magnet as it contains elements like where balls go in the field or how events stack up on each other, which can alter how well ability will translate into an outcome.  The result is simply that outcome.

Let’s step through this graphic piece by piece.

This category can go by a lot of names, so we should not be too hung up on whether I chose to name this the right thing.  What I mean to put in here is basically the sum result of active elements, items that we can be informed about, items that we are able to change by choice.  This includes traditional concepts of team like talent, training, health, and coaching; but also items that perhaps people do not think about as much, such as scheduling.  All of these elements affect how well a team can perform.  That level of performance is what we are trying to find when we look to name a team the best at something.  However, this is a very difficult thing to measure.  It may well be impossible to measure, so we try to find a way to determine who has the best ability.

The way we try to figure this out is by converting ability into wins by the way of runs scored and runs given.  This is how we define the outcome of a single game.  With a sport where the best team won 60% of their games and the worst won 34% of their games, it takes a pretty long season to figure out which team is the best.  This is not like football where you can have a team flirt with perfection one way or another.  In baseball, you need a larger sample size than 16 to figure it all out.

Right?  Well, that is because wins are an imperfect measure of which team has the most ability.  Why is a single win not a sufficient way to measure how good a team is?

This is another section to not get too bog down into what it is called.  You can call this component fortune, luck, chance, randomness, etc.  Basically, this grouping is what makes wins an imprecise measure of which team is the best because it will affect how ability is converted into wins.
An example, Balls in Play.

This is something we have all experienced multiple times playing this game or watching it.  One team is striking guys out left and right while putting up an extra base hit every inning while the other team somehow manages to have balls hit right to them when the opponent is in scoring position and managing to have a wind aided ball carry just over the fence.  With our eyes, we see that the better team lost.

There is nothing that can be trained or taught that can shift a hard hit line drive straight to a second baseman versus five feet to the right.  That is the same amount of ability from the batter, but one ends in an out and the other might turn into a double.  That is an error in conversion.  The hope is that by playing 162 games that the noise that the conversion error generates will be muted…that the signal (who is better) emerges from the messy noise of wins and losses.

But What About the Post-season?
Well, after using the entire season to figure out who the best teams are, we do not have many options left.  We accept a shorter schedule that will award one of the best teams with a championship.  The championship is not designed to determine which team is truly the one with the best ability, merely the best possible way to figure out who might be.  One game series will not figure out which is the better team, nor will seven game series.

That is OK.  We do not need the World Series to definitively determine which team is best.  It works merely in determining who wins the most, which can be different from which team has the most ability.

Restating It All
So, the basic fact of this is that wins are an imperfect measure of the best team.  Ability does not neatly translate over to wins because there are elements beyond ability that affect that conversion.  That is OK.  With a long enough season, differentiation can be good enough to set up a playoff among many of the best teams.  A shortened post-season is fine because trimming away the lesser teams and letting the best teams duke it out is a sound approach.  However, we know that the team with the most wins is not automatically the best team.  They might be, they might not.  And that is OK.

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