XFIP, or Fielding Independent Pitching, tries to eliminate the effects of defense on a pitcher's performance
I usually like advanced stats and can find a use for most, but IMO FIP (the X variety or otherwise) does not achieve its aim. There is nothing in FIP that, for example, depends on whether Buxton or Cave is in CF. Simply put, it doesn't eliminate defense, it eliminates from consideration the part of the game that makes it baseball and substitutes average performance in its place.
Much simpler for me is to look at OPS-against. League-wide, you can draw a rough comparison of OPS to the ERA that you could usually expect. Pineda for instance has an OPS-against of .809, and over the years that has worked out to an ERA somewhere a little north of 5.00. Not good, which we already know.
Gibson's OPS is .750, and ordinarily that should result in an ERA like 4.35.
Perez, .700, for an ERA equivalent around 3.75.
Berrios, .666, which I'd expect an ERA around 3.20 or so.
Odorizzi? Batters have a BA against him of .181 coming into this game, built on an unusually low BABIP of .243. The OPS is a minuscule .511, so low that I'm not even confident what ERA it translates to on a league-wide basis, but let's safely say it would be under 2.00. Which is where he is.
Really, all our starters are giving up runs about in line with the underlying hitting stats against them.
xFIP says that a certain percentage of flyballs go out, and Odorizzi hasn't given up his fair share so xFIP reflects skepticism. BABIP usually doesn't stay as low as .243, so there is another reason to expect more hits to fall in.
But he's leading the league in ERA right now. Simple "regression to mean" logic would point toward not keeping up the pace for the rest of the season. xFIP doesn't win any points from me for merely predicting that.
Meanwhile Jake has logged another very good 6 innings today. We keep expecting regression, but so far, he just keeps chugging along.