Stolen Goods: Why You Can't Subtract FIP from ERA

While perusing through some old sabermetrics articles on The Hardball Times, I came across this article by Colin Wyers explaining why the ERA-FIP ("E-F") stat is not particularly a scientific measure of regression (See graph, below).



Neither FIP, tERA or xFIP has quite the same range or slope as ERA. As Wyers explains:

"This doesn't mean that FIP is useless, of course - it should do a good job of putting pitchers in the right ordinal ranking - the best pitchers will generally have the lowest FIPs and the worst will have the highest, at least within the limits of sample size. But what it will do is distort the distance between the best and worst pitchers."

Quite the interesting read, I recommend checking it out.