James Shields will make his fourth start tonight and his second against the White Sox. Those who simply look at earned run average are probably happy with Shields, but those who value fielding independent metrics might be sour on his performance. To date, Shields has a 3.98 ERA, 4.78 FIP, and 4.40 xFIP –those would be career worst FIP and xFIP measures, while his ERA would be a personal best since 2008.
The peripheral-based run metrics are angry over Shields’ pedestrian strikeout rate. Seeing Shields fan fewer than five batters per nine innings pitched is as jarring as finding out that Shields has a .269 batting average on balls in play or that 18 percent of his flyballs have been of the infield variety per Baseball-Reference. It’s too early to say whether any of those numbers will sustain, but one thing it probably isn’t too early to talk about is Shields’ pitch usage. He has looked like a different pitcher, to wit:
Everyone who wanted Shields to use his fastballs less (cutter included) are getting their wish. Shields has dropped his usage across the board. So far, Shields has even abstained from throwing a first-pitch changeup to a lefty. Rather than go after hitters and pitch to contact, Shields is pitching backwards: lots of first-pitch curves and sliders and an overall increase in his breaking stuff usage.
Pitching backwards only works if Shields can locate his breaking stuff for strikes–which, in theory and often practice, should be more difficult than throwing a fastball for a strike. Sure enough, Shields is falling behind more often (he has gone to 1-0 43.7 percent of the time, as opposed to 39.3 percent in previous years), while getting ahead less often too (43.7 percent too, as opposed to 46.9 percent in the past).
Ultimately, these changes might not be a good thing. Shields has given up a higher rate of extra-base hits per plate appearance this season than he did in 2010 (48 percent to 37 percent—Shields’ career average is 37 percent as well) and his walk rates have remained static. His strikeout rate has dipped. If Shields continues to pitch like this, his ERA is unlikely to stay low. For once, though, it may match his fielding independent stats.