Wednesday, August 22, 2012

Batted Ball FIP

Fielding Independent Pitching (FIP) is an ERA estimator.  It attempts to show what a pitcher’s ERA should look like given an average defense behind him.  It factors in what the pitcher can control; basically home runs and walks are bad, strikeouts are good.  Here’s the formula:

FIP = ((13*HR) + (3*BB+HBP))-(2*K))/IP + Constant

The constant puts it on the same scale as ERA and will be different each year as the run environment changes.

I found this by Tangotiger, who tweaked the formula to included batted ball data.  Infield fly balls (pop-ups) almost always result in an out, so they are very similar to getting a strikeout.  Line drives result in a hit at a very high rate, so they are similar to giving up a walk.  Ground balls and fly balls are somewhere in the middle (about one-fourth between BB and K according to the article).  The formula is:

ERA = 11*bigs + 3*smalls + Constant

Bigs = ((BB+LD) – (K+IFB)))/PA
Smalls = (OFB-GB)/PA

And BB are actually BB – IBB + HBP.

I did some number crunching to see how the Tigers pitching is performing in this bbFIP stat so far this year:

Max Scherzer – 3.20
Drew Smyly – 3.54
Doug Fister – 3.65
Rick Porcello – 4.34
Anibal Sanchez – 5.76 (only time in DET)

Relievers (min 20 IP):
Octavio Dotel – 1.74
Joaquin Benoit – 2.98
Phil Coke – 3.74
Jose Valverde – 4.67
Duane Below – 4.81

The Tigers as a team are at 3.79 bbFIP. 

It is shocking to see Max Scherzer at the top of the starters list instead of Justin Verlander.  

SIERA is another ERA estimator that also uses batted ball data, but it is a lot more complicated.  Here’s how the Tigers pitchers fare in this stat:

Max Scherzer – 3.05
Justin Verlander – 3.27
Doug Fister – 3.34
Drew Smyly – 3.62
Rick Porcello – 3.97
Anibal Sanchez – 4.76 (only time in DET)

Relievers (min. 20 IP):
Octavio Dotel – 1.99
Joaquin Benoit – 2.75
Brayan Villarreal – 2.94
Phil Coke – 3.40
Duane Below – 3.86
Jose Valverde – 4.29

Max Scherzer again is leading in SIERA.  In fact, he’s leading the entire American League in SIERA and trailing only Stephen Strasburg (2.72) and R.A. Dickey (3.00) for the Major League lead.  It makes me wonder how Scherzer would do with a better defense behind him.  This also puts it into perspective how amazing his season really is with his high strikeout rate, 11.34 K/9.

Is Scherzer the most under-rated starting pitcher in baseball?  A good argument can surely be made for it.

1 comment:

  1. Nice article with some good information you won't find just anywhere.