Wednesday, January 20, 2010

WAR - it is good for something after all (Part 1)

Settle down, dirty hippies. I'm talking about a baseball stat.

After posting some travel thoughts, food thoughts, and deep thoughts about the state of our cities, it's time for a good old-fashioned nerdy baseball post. WARNING, WARNING!! This post contains numbers and a stat you can't find by reading the Pittsburgh Post-Gazette!

One of my favorite new-age baseball stats is WAR or Wins Above Replacement. It was developed by Dave Cameron who is the main contributor to his own blog "U.S.S. Mariner" and another great website called "Fangraphs". The main concept of WAR is to determine how many wins a certain player is than if he was replaced by a run-of-the-mill AAA player that never has achieved success at the major league level. This AAAA-type of player is called Replacement Level...a readily available commodity that can be paid the major-league minimum. For instance, Andrew McCutchen last year was a 3.4 WAR player, meaning he was worth an extra 3.4 wins to the Pirates over some typical AAAA-level scrub.

WAR is for both pitchers and batters. For batters, there are 4 main things (with a bunch of little things in each of those four things):
Positional Adjustment
Replacement Adjustment

The detailed description of these items for batters and pitchers can be found here...

...but the thumbnail sketch is this:
Batting - based on stats accrued during the season (BA, OPS, K rate, etc)
Fielding - based on a defensive metric called Ultimate Zone Rating to account for range, arm strength, errors, etc)
Positional Adj - some positions are harder to play than others and if you play one of them, you either get extra credit (SS, CF, C, 2B, 3B) or deducted (1B, DH, LF/RF)
Replacement Adj - this is based on a 600 plate appearance season, so you get a percentage of the points if you are less than 600 PA's

The same concept applies to pitchers, but primarily revolves around a metric called FIP (Fielding Independent Pitching). This metric takes the defense out of the equation and sees what a pitcher's ERA would look like based on his own merit. It gauges a pitcher's strikeouts, walks, and home runs allowed...all things that the pitcher is solely responsible for. Just because your SS had a bad night does not factor into FIP.

Again, consult the glossary above for more explanation.
Not only can you determine WAR for each individual player, but then you can aggregate it for the whole team and determine how many total wins that team may or may not achieve. It is a good predictive model for a season.

In my next 2 parts, I'm going to look at how WAR did as a reflection on each MLB's teams win total from 2009 and then I'm going to break down each of the players on the potential 25 man roster for the Pirates to determine the 2010 Pirates' win total.

Number crunching at its finest!

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