xFIP uses statz! on WORLD SERIES TROPHY! It's not very effective...
Dear Viceroy of Stats,
First off, thank you for the stats. If I were to do a line graph comparing my love for baseball and the rise of the internet, the two lines would start rising dramatically around 1996 without a single dip. The stats are a big part of that. One of my favorite things in the world is feeling superior to other people. Now when someone references RBI, I know I’m objectively better than them in every capacity. You can’t buy that feeling, and I have stats to thank. Plus, when people argue about "sabermetrics" vs. "sabremetrics", it reminds me of the Northern Conservative Baptist Great Lakes Region Council of 1912 joke,and that’s always a good thing.
But I also remember those early days of the internet stats. No-hit, all-glove wizards were not tolerated. Teams and GMs who signed players like Royce Clayton, Rey Sanchez, and Mike Bordick were mocked without mercy. The new stats, though, tell us that some of those guys had pretty valuable seasons. Jose Vizcaino, for whom I had a strong distaste in 1997, was actually a 2+ win player that year. Well, I’ll be. This isn’t to suggest that because the methods of evaluation have changed, people should discount every innovation because it’s likely to be considered wrong in a decade. Of course not.
It might not be a bad idea, though, always to assume that stats are likely to contain some measure of imperfection. When I see single-season WAR totals used with a dogmatic certainty, it makes me uneasy. I have a feeling that the formula for WAR will be updated and tinkered for years, if not decades, because it’s surely tricky to combine hitting stats with something as variable as single-season fielding stats to produce a single number. Yet there’s a small faction among us who likes to use single-season WAR as a blunt object. It feels like some folks -- certainly not most or all -- use the stat without the spirit of intellectual curiosity with which it was created.
So I’ve searched for the most diplomatic way to phrase this, and I think I’ve arrived at something that fair, honest, and non-combative. Here goes: Matt Cain is good, and people who use xFIP as a blunt object can shut their yap holes. The idea of normalizing ERA to account for luck with balls put in play is a fine one. Trying to normalize home runs per fly all is a good idea too. Assuming that the current construct will work as an infallible predictive tool for every single pitcher in professional baseball right now? Not my favorite idea.
Matt Cain has outperformed his FIP for four straight seasons. He has probably benefited from some measure of luck, especially in 2009, when he beat the mark by a full run. The traditional stat, ERA, indicates that Matt Cain is an elite pitcher. FIP suggests that Cain is merely very good. That’s a fair debate. Pitchers can do that sort of thing for an entire career, but they’re the exceptions, not the rules. The burden of proof would probably be on the person suggesting that Cain is elite.
However, xFIP suggests that Matt Cain is an innings-eater of the most ordinary capacity, like a Jon Garland or a Joe Blanton. Matt Cain’s career xFIP is 4.43, and aaaaaaany day now, his ERA will regress to meet that mark. Some people pounce on that, and they froth at the mention of Matt Cain as a top pitcher. And I’m forced to react like a troglodyte, mentioning that a) I’VE TOTALLY WATCHED, LIKE, EVERY ONE OF HIS STARTS, AND MY EYES ARE MORE BETTER THAN YOUR STATS, and b) but his ERA! I don’t like both of those arguments. I can link to a study by the wizard who actually invented FIP, which acknowledges that there could be outliers like Cain when calculating xFIP, but because the math hurts my brain, I can’t do anything but appeal to his authority.
It feels like with some folks, you get "Matt Cain’s xFIP is this. His ERA is that. The difference means there is something wrong with Matt Cain." I would like more, "Matt Cain’s xFIP is this. His ERA is that. Maybe there’s something that makes this happen every year." That’s all. I would just like the small, vocal minority to use stats like WAR, FIP, and xFIP as useful tools, not divinely inspired scripture just yet. Please command them to do so with your powers as Viceroy of Stats.
I would like to end this open letter by noting that Matt Cain did not allow an earned run this postseason, and contrary to popular belief, that performance has tremendous predictive value. I predict that in 20 years, Matt Cain’s performance in the 2010 playoffs will still have been totally awesome.
Some English Major