The top four starters in the Detroit Tigers’ rotation – Justin Verlander, Anibal Sanchez, Doug Fister and Max Scherzer – all have better FIP than ERA. This is generally because the Tigers’ defense, notably in the infield, is well below average. These pitchers, however, boast high enough strikeout rates that the poor defense behind them is not prohibitive to their success. Those four starters also have an xFIP that is between their FIP and ERA. This indicates that they’re all enjoying better-than-average success preventing home runs, but the defensive adjustment outweighs it.
The Tigers’ fifth starter Rick Porcello has a similarly lower FIP, due to the same poor defense. He, however, has an even lower xFIP because – contrary to his four rotation mates – has had a miserable time preventing home runs. While the other four pitchers allow home runs on between 3.6-7.5% of fly balls, Porcello is allowing 19% of fly balls to leave the ballpark. While some of this is surely attributable to Porcello’s pitching, he has still endured some amount of bad luck. Having pitched nearly 700 innings before this season, Porcello had allowed about 11% of fly balls to be home runs.
While the other four Tigers’ starters should regress to at least some extent, Porcello should only improve upon his 4.86 ERA. With a 3.67 FIP and 2.97 xFIP, it is not unreasonable for Porcello to have a mid-three ERA for the remainder of the season. With a career high strikeout rate, he has maintained his already-low walk rate.
According to Fangraphs, Porcello is throwing his slider significantly less. Hitters hit .394 against his slider in 2012, so this adjustment in style is clearly helping. Porcello has, in turn, upped the number of changeups he throws. His changeup is a plus pitch, and hitters have consistently hit .250 or below against it for the entirety of his career.
With these adjustments in approach and some regression on home runs, Porcello could parlay a strong second half of 2013 into sustained success for years to come.
Gabe Isaacson is a writer for RantSports.com. Follow him on Twitter: @gabeisaacson.