Comments on: Should Fantasy Owners Use FIP?

By: David MVP Eckstein

David MVP Eckstein — Wed, 10 Feb 2010 02:04:31 +0000

what were the results???

By: Derek Carty

Derek Carty — Tue, 21 Jul 2009 04:52:01 +0000

Nadav,
“assuming that his mix of ballparks will be HR-neutral” and “assuming that his mix of *ROAD* ballparks will be HR-neutral” are two completely different things. We should absolutely account for home park separately, but unless we want to get super in-depth mid-season (like I do with CAPS during the off-season), it’s impossible to put an exact number on a pitcher’s future road ballparks. You admit this, so I agree that it’s fine to make mental adjustments if you see that a player’s upcoming games are in extreme parks. My point remains, though, that xFIP is better than FIP and that assuming a neutral mix of road ballparks is fine unless you want to take the time to dig through schedules.

By: NadavT

NadavT — Mon, 20 Jul 2009 21:11:09 +0000

I guess we’ll just have to disagree on this one. If you’re taking the time to project a pitcher’s performance for the rest of the season, I don’t think it’s sufficient to go with the “simplest way” by assuming that his mix of ballparks will be HR-neutral. Clearly, you can’t pin down every ballpark he’s going to start in for the rest of the season, but you know that his home games will be HR-friendly and you can make guesses based on the remainder of the Phillies’ schedule. I’m not suggesting that one can apply a mathematical adjustment to FIP or xFIP based on this, but I maintain that it makes sense to keep in mind that xFIP might be biased downward in projecting his performance for the rest of the season.

By: Derek Carty

Derek Carty — Sun, 19 Jul 2009 19:24:41 +0000

labe,
tRA is one I would probably avoid as well. I imagine it’s better than ERC and probably FIP, but worse than LIPS, xFIP, QERA, etc. tRA uses HR and LD, both of which are mostly out of a pitcher’s control, so it has much the same problem as FIP.

tRA*, however, regresses each stat to the mean to account for the fact that HR/LD/etc aren’t heavily controlled by the pitcher. While I prefer LIPS, tRA* doesn’t seem to have any of the glaring flaws that FIP and ERC do. I haven’t run any tests on tRA*, but I imagine it’s at least in the same class as xFIP and QERA based on its methodology.

In summary, if you’re going to use one of the two, definitely go with tRA*, although xFIP and QERA are also great freely available options.

By: Toffer Peak

Toffer Peak — Sun, 19 Jul 2009 18:52:34 +0000

FIP
Fielding Independent Pitching, a measure of all those things for which a pitcher is specifically responsible. The formula is (HR*13+(BB+HBP-IBB)*3-K*2)/IP, plus a league-specific factor (usually around 3.2) to round out the number to an equivalent ERA number. FIP helps you understand how well a pitcher pitched, regardless of how well his fielders fielded. FIP was invented by Tangotiger.

xFIP
Expected Fielding Independent Pitching. This is an experimental stat that adjusts FIP and “normalizes” the home run component. Research has shown that home runs allowed are pretty much a function of flyballs allowed and home park, so xFIP is based on the average number of home runs allowed per outfield fly. Theoretically, this should be a better predicter of a pitcher’s future ERA.

http://www.hardballtimes.com/main/statpages/glossary/

xFIP multiplies the number of outfield flys by 11% to get the predicted number of HRs (although it should probably be closer to 10% and for fantasy purposes should be adjusted by 50% toward the player’s home park).

By: labe

labe — Sun, 19 Jul 2009 04:03:13 +0000

derek,

Where do you think tra and tra* fit into the picture? which of the two is better for predicting future performance? thanks.

By: Derek Carty

Derek Carty — Sun, 19 Jul 2009 00:30:04 +0000

BobbyRoberto,
My tests have shown that QERA is a pretty good one, which it logically should be since K, BB, and GB are really what we need to be focusing on. The ERA estimators we really want to avoid are FIP and ERC.

By: BobbyRoberto

BobbyRoberto — Sat, 18 Jul 2009 18:11:29 +0000

Brian (or anyone else who might have an idea),
What do you think of QERA, which is sometimes used at BP? It uses K-rate, BB-rate, and GB-rate. I calculated the QERA for pitchers on my fantasy teams and it comes out fairly close to xFIP.

By: Derek Carty

Derek Carty — Sat, 18 Jul 2009 03:02:39 +0000

You’re right Nadav, but the problem is that Hamels won’t experience that same mix of road parks going forward, so assuming he will is flawed thinking. This kind of thing is completely out of his control, so unless we want to go park by park and at-bat by at-bat and make adjustments (which I do in the off-season), the simple way is to simply assume that he’ll have neutral luck and a neutral mix of parks going forward.

By: Brian Joura

Brian Joura — Fri, 17 Jul 2009 19:57:20 +0000

Hi bballrox thanks for reading and commenting!

The test is between FIP and xFIP not ERA, since it is known that FIP does better than ERA in predicting future ERA. I am only looking for a 50-point difference between FIP and xFIP.