xFIP

[texasdave]

I don't really pretend to know all the ins and outs of xFIP, but I thought it was premised upon things that pitchers (supposedly) control. Like strikeouts and walks and home runs. Now maybe the accuracy of xFIP does not kick in until a certain level of innings pitched has been reached. I don't know. But here are the current xFIP numbers of the Reds' five starters. Do they look like they match up with the performances we have seen on the field so far this year?


Name xFIP
Leake 3.66
Cueto 3.78
Arroyo 4.08
Latos 4.12
Bailey 4.38


Has Mike Leake really been the Reds' best starting pitcher? Is Johnny Cueto an average pitcher and not an ace? Have Latos and Arroyo honestly pitched better than Bailey? Is Homer our worst starter?

Maybe someone can explain or put these numbers into their proper context. Looking at this I simply have no use for xFIP because it certainly doesn't match up with reality as I see it. Not even close.

http://www.fangraphs.com/leaders.aspx?pos=all&stats=pit&lg=all&qual=y&type=8&season=2012&month=0&season1=2012&ind=0&team=18&rost=0&age=0&players=0&sort=16,d

[Larkin88]

I don't really pretend to know all the ins and outs of xFIP, but I thought it was premised upon things that pitchers (supposedly) control. Like strikeouts and walks and home runs. Now maybe the accuracy of xFIP does not kick in until a certain level of innings pitched has been reached. But here are the current xFIP numbers of the Reds' five starters. Do they look like they match up with the performances we have seen on the field so far this year?


Name xFIP
Leake 3.66
Cueto 3.78
Arroyo 4.08
Latos 4.12
Bailey 4.38


Has Mike Leake really been the Reds best starting pitcher? Is Johnny Cueto an average pitcher and not an ace? Have Latos and Arroyo honestly pitched better than Bailey? Is Homer our worst starter?

Maybe someone can explain or put these numbers into their proper context. Looking at this I simply have no use for xFIP because it certainly doesn't match up with reality as I see it.

http://www.fangraphs.com/leaders.aspx?pos=all&stats=pit&lg=all&qual=y&type=8&season=2012&month=0&season1=2012&ind=0&team=18&rost=0&age=0&players=0&sort=16,d

Tough to look at any one stat in a vaccuum, because none of them tell the whole story. For instance, if Cueto is able to maintain a freakishly low BABIP as he has the last two years, there's a good chance his ERA will always outperform his fielding independent measures, as these are usually based on some league average constants.

xFIP specifically is a normalized metric too. Meaning it replaces a pitcher’s HR rate with an estimate of how many home runs they should have allowed, based on league averages. So for guys like Latos who has been getting shelled with homers, replacing that constant with a normalized league average number actually improves his numbers expected performance.

EDIT: here's a much better explanation than I could give in my limited time - http://www.fangraphs.com/library/index.php/pitching/xfip/