Michael Pineda's inability to get hitters out with runners on base is well documented. Since 2015, his left on base percentage (LOB%) is under 70%, which is below the league average. Stats like LOB% are expected to regress to the league average over a large sample size. With Pineda's stellar strikeout and walk numbers, one might even expect his LOB% to be above league average, not consistently below it.
To make matters worse, Pineda has had the bad habit of giving up home runs with runners on base. Since 2015, Pineda has allowed 19 homers with runners on, tying with Jered Weaver and Ian Kennedy for the highest total in baseball. If a pitcher gives up grand slam, technically there are no runners left to strand anymore. So Pineda's already low LOB% might actually be overestimating his ability to pitch out of the stretch.
Last month, Fangraphs' August Fagerstrom noticed something weird about Jose Fernandez. Against the Marlins' ace, hitters were more than twice as likely to make contact on pitches in the strike zone than on pitches out of the zone. In sabermetric terms, the ratio of Fernandez' Z-Contact% to his O-Contact% was greater than two. Michael Pineda's Z-Contact%/O-Contact% ratio was fifth among qualified starters at roughly 1.7.
If someone only watched Jose Fernandez pitch, he or she might be fooled into thinking that coming back from Tommy John surgery isn't hard. In 15 starts, he has over 13 K/9 with a 2.28 ERA. Pineda, on the other hand, has a 5.24 ERA. In the New York market, saying, "But my FIP is under 4" probably wouldn't be very well received.
Numbers aside, the two starters actually have a decent amount in common. They both throw their fastballs in the mid to upper 90s and rely on a nasty breaking ball, using a changeup more sparingly. Fernandez has better stuff than Pineda, and there are no two ways around it. But despite having better stuff, Fernandez's approach is basically the same regardless of whether there are runners on base:
|Pitcher||BB% (Bases Empty)||BB% (Runners On)|
With runners on base, Fernandez's walk rate drops a bit, while Pineda's virtually disappears. For good measure, someone like Masahiro Tanaka, who lives on the corners of the strike zone, is actually more likely to issue a walk with runners on base.
For what it's worth, Pineda has actually decreased his Zone% this season. Hitters are still destroying his four-seam fastball, and he has stopped throwing his cutter, presumably for good reason. But one way to limit the damage with runners on base could be to simply pitch the way he would if the bases were empty, worrying less about walks. After all, Zack Greinke, Noah Syndergaard, and Tanaka are the only qualified starters who have been better than Pineda at getting hitters to chase outside the strike zone.
Fresh off two straight starts with six innings pitched and one run allowed, Pineda has the opportunity to finish strong after a shaky first half. After his start in Minnesota on June 18th, his ERA reached 5.82. But he still has plenty of time to salvage the season after the All Star break. Hopefully, his last two outings are a sign that Michael Pineda has turned a corner and is ready to live up to his potential.
Data is courtesy of Fangraphs.