15 February 2012

Jason Hammel Will Likely Not Throw His FIP

One of the interesting aspects of the Orioles deal with the Rockies is that they exchanged one pitcher, Jeremy Guthrie, who is one of the more exceptional pitchers in performing better than his Fielding Independent Pitching (FIP) would indicate for another, Jason Hammel, who is one of the most consistent pitchers who does not match his FIP.  As I wrote in the previous Hammel and Guthrie column, it may be that both pitchers affect BABIP and the quality of the contact.  That would not be something FIP would be able to use.

For those who are unaware of FIP, it is a statistic that Tom Tango devised based on Voros McCracken's seminal work on what parts of the game a pitcher significantly affects.  It uses the following formula:
FIP = constant + ((13*HR) + (3*(BB + HBP - IBB)) - (2*K)) / IP
If you want to napkin scratch it, the constant is 3.2.  However, if you want to be more accurate then you use the following formula:
constant = (league average FIP) - (league average ERA)
This constant is used to give FIP a closer look to ERA.  That way it is easier for the audience to understand FIP as it is translated to our understanding of ERA.  As we have seen, there is good evidence that some pitchers can actually affect the quality of contact.  It does not appear to alter the usefulness of FIP for a large majority of pitchers, but FIP does appear to consistently over or under measure some pitcher's performance.

Two lists are presented below.  The first consists of the ten pitchers over the past five seasons who logged over 500 IP and have outperformed there FIP the most.  The second list is the top ten of those whose FIP indicates a much high performance level than what actually transpired.  Jeremy Guthrie was the 6th best at outperforming his FIP.  Jason Hammel was the 3rd worst against his FIP.  This does not mean that Guthrie is good and Hammel is bad.  It means that FIP does a poor job with either of these pitchers.  FIP pretty much says that the typical pitcher with Guthrie's walks, home runs, hit by pitches, intentional walks, and strikeouts should do much worse than he actually does.  I think this probably means he does a better job than most pitchers in inducing poor quality contact.  FIP says that a typical pitcher with Jason Hammel's walks, home runs, hit by pitches, intentional walks, and strikeouts should do much better than he actually does.  Conversely, it seems that batters get better quality contact on batted balls.

Pitchers who have overperformed their FIP from 2007-2011:
1. Johan Santana Twins/Mets -0.68 ERA - FIP
2. Armando Galarraga Tigers/Diamondbacks -0.66
3. John Lannan Nationals -0.60
-. Trevor Cahill Athletics
5. Joe Saunders Angels/Diamondbcks -0.58
6. Jeremy Guthrie Orioles -0.56
7. Kyle Kendrick Phillies -0.54
8. Tim Hudson Braves -0.53
-. Shaun Marcum Blue Jays/Brewers
10. Bronson Arroyo Reds -0.49

Pitchers who have underperformed their FIP from 2007-2011:
1. Luke Hochevar Royals 0.96 ERA - FIP
2. Ricky Nolasco Marlins 0.79
3. Jason Hammel Rays/Rockies 0.69
4. Francisco Liriano Twins 0.68
5. Kyle Davies Braves/Royals 0.58
6. Zach Duke Pirates/Diamondbacks 0.45
-. Jorge De La Rosa Royals/Rockies 0.44
8. Kevin Slowey Twins
9. Jeff Francis Rockies/Royals 0.42
10. Brian Bannister Royals 0.39
It has been suggested before that perhaps discrepancies between FIP and ERA could be explained by poor infielding or outfielding.  Johan Santana, Francisco Liriano, and Kevin Slowey give us a solid comparison as they appear on either list and we can compare ground ball and fly ball rates.  Santana outperformed his FIP and had a 37.6% ground ball rate and a 42.7% fly ball rate.  Liriano and Slowey underperformed against their FIP.  Liriano had a 47.0% ground ball rate and a 35.1% fly ball rate.  Slowey had a 31.6% ground ball rate and a 47.9% fly ball rate.  Santana's rates fall right in the middle of them, so this simple comparison does not implicate infield or outfield defense affecting the FIP discrepancies.

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