## Introducing Statistics: Fielding Independent Pitching

I would like to introduce an advanced stat today. Given all of the award talk and Hall of Fame talk in the last week on this site, it seems useful to introduce statistics by which players can be evaluated. The stat for today, fielding independent pitching (FIP) is one such stat used to isolate the performance of pitchers. It starts from a very simple problem and then attempts to resolve it as simply as possible. How can pitching and fielding be separated?

The statistician Voros McCracken began work on this problem in the late 1990’s. Start with this observation: it was easier to pitch for the St. Louis Cardinals in the 1980’s with Ozzie Smith behind you than to pitch for the Cardinals in 2000 when supported by Edgar Renteria. This has nothing to do with the inherent talent of the pitcher and is instead completely dependent on the talent of his shortstop. The influence of parks on pitchers and hitters has been studied for a long time, and park factors were developed in an attempt to isolate them. The impact of fielding, though always known intuitively, has gotten its best study only recently. McCracken argued that pitchers have minimal control over the percentage of balls hit into play that are turned into outs. Instead, pitchers seem to control 5 factors, walks, strikeouts, home runs, hit batsmen, and intentional walks. These factors correlate highly from year to year, not changing dramatically if a pitcher switches teams or if a team switches important defenders. In contrast, hits vary wildly depending on factors outside a pitcher’s control, which has the corollary that so does earned run average. To account for this McCracken created a stat called defense independent ERA.

If you click through the link, you see that dERA is brutally complicated. Because of this, two other sabermetricians developed simpler formulas for what is now called FIP, Clay Dreslough and Tom Tango. (FIP is the name Tango gave his stat; Dreslough nearly identical stat was called DICE.) These two authors simplified the formula to this:

FIP={13HR + 3BB – 2K}/IP

Since this original formula, a 3.2 has been added to the end to convert this number into something that more nearly resemble ERA. The second term in the numerator has also been updated to 3(BB+HBP).

What does FIP tell you about this season? Zack Greinke and Tim Lincecum are the best pitchers in baseball. Incorporating relievers changes this, pushing Jonathan Broxton and Brian Wilson to the forefront. As this should tell you, FIP relies heavily on strikeout rates and will always push high strikeout pitchers to the leaderboard. Groundball pitchers, in turn, are much more dependent on having reliable defense behind them.

**Explore posts in the same categories:**Baseball, Statistics

**Tags:** Fielding, Pitchers, Sabermetrics, Statistics, Tim Lincecum, Tom Tango, Voros McCracken, Zack Greinke

09/24/2009 at 1:46 pm

Baseballbriefs.com tracking back Introducing Statistics: Fielding Independent Pitching…Baseballbriefs.com tracking back Introducing Statistics: Fielding Independent Pitching…

09/24/2009 at 9:32 pm

Where do people come up with these stats? Honestly, I just don’t get it! Enjoy a game! Eat a hot dog for goodness’ sake!