Wins should never be used to evaluate a pitcher. A pitcher can only get a win if enough run support is provided. Cliff Lee and Bruce Chen both have 12 wins this season. Are these two pitchers just as good as each other? No.
Earned run average (ERA) has been commonly used to evaluate pitching performance. While it is a useful statistic, it does not take into account the team defense’s effect on pitching performance. A pitcher pitching behind a poor defense will give up many hits and appear to have a poor ERA.
The way around this is to focus only on what the pitcher controls: home runs, strikeouts, walks and hit-by-pitches. Linear weights are applied to each statistic, combined and divided by innings pitched to create fielding-independent pitching (FIP). FIP is useful in that it only isolates the statistics a pitcher has control over.
Fielding: Derek Jeter won three Gold Glove Awards from 2004-2006, as his sure-handed fielding and accurate throws resulted in few errors. The relative high fielding percentage from Jeter masked his poor range, and ultimately poor defense, which cost the Yankees 22.9 runs over those three seasons.
Calculation of fielding ability using Ultimate Zone Rating (UZR) is very complicated. Imagine a baseball field cut up into 78 zones, in which 64 are used. For each zone, a computer keeps track of the number of hits in the zone, the average run value of a hit in the zone and the number of outs recorded for each position in the zone. A fielder who makes enough plays inside his responsible zones and possesses enough range to make plays in outside zones will earn positive fielding value.
Carl Crawford leads all of baseball this season with a +22 UZR. Infielders are evaluated by range, errors and double plays, while outfielders are evaluated by range, errors and arm. Catcher fielding evaluations are currently being developed.
Value: Cumulative run values can be converted into win values and ultimately into money. For a position player, hitting, fielding, replacement and position are all variables to be added for value. Replacement is a measure of durability, and is set at 20 runs for 600 plate appearances. Position adds or subtracts runs, according to the position played, as replacement-level players vary according to position.
Catchers get a 12.5 run boost, while designated hitters start with a 17.5 run handicap. The other positions fall somewhere in between. Pitchers are only evaluated with pitching run values.
This adds up to the amount of runs above replacement (RAR) a player is. This could be divided by 10 to simplify, and converted into wins above replacement (WAR).
Using free agent market values, we could determine how much money a player earned or cost his team. Ultimately, this could be used to gauge how much money a player should earn. In 2009, the value of a win was $4.3 million, but the economic pressures this year dropped the value of a win to $3.9 million.
This is just a glancing overview of basic sabermetric principles. Many other important measures are crucial for a better understanding of the subject, and more research is being conducted every day.
So the next time you are talking baseball with someone, throw in a FIP or WAR in there, it will definitely give you an air of untouchable baseball intelligence.
