In his past two seasons with the Tampa Bay Rays, Jeremy Hellickson has been a successful starting pitcher while outperforming his ERA estimators (FIP, xFIP, SIERA). Despite low strikeout rates and an above-average BB/9, Hellickson managed to post a low ERA thanks to a high LOB% and a low BABIP.
Unfortunately the tables have turned on Hellboy in 2013. Through 11 starts (69.0 IP), all of his numbers look completely different outside of his ERA estimators (4.66 FIP this year is just a tad higher than his career FIP). His K/9 and BB/9 rates are actually better than his career numbers so far, his ERA currently sits at a lopsided 5.61 and his BABIP—which is still below league average at .273—is relatively high.
The most noticeable metric difference in 2013 has been Hellickson's shockingly-high LOB%, which has dropped about 20% from 2011/2012 (82% to 62%). Another 'luck statistic' that has seen a rise this season is Helly's HR/FB ratio. At the moment it stands at 13.5%, which is 3% higher than his career average.
So it appears that Hellickson, who has always been considered a lucky pitcher, has maybe ran out of luck.
There's of course more to Hellickson's struggles than just misfortune, however. His fastball command, for one, hasn't been good. He's pitched more inside the strikezone, which has led to the improved strikeout/walk rates, but at the same time caused him to get it harder.
His pitch usage this year has been pretty similar, but I have noticed a couple differences that could have some significance.
Hellickson has inexplicably thrown a very high amount of changeups against right-handed batters this year, especially with two strikes (46% of the time). I've also noticed that he's left his changeup—which is usually a very good one—up in the zone too often this season.
It appears that Hellickson is maybe relying too much on his changeup (against right-handed batters), or at least not utilizing it ideally. About a quarter (25.40%) of the balls put in play off his changeup are line drives, which is well above the norm for him.
Another one of Hellickson's secondary pitches to keep an eye on is his curveball, which he made huge strides with in 2012. He's thrown it 17% of the time this season, which is 5% more than last year. Despite showing a lot of potential last season, it hasn't really been much of an effective pitch for him in 2013. With the hook he's posted a whiff/swing rate of just 20.78%, which is over 11% lower than his career rate.
Another probable cause for Hellickson's struggles is his diminished fastball velocity. The average velocity on his four-seamer so far this season is just 90.64 MPH, a whole 1.61 MPH slower than 2012. The decreased velocity could possibly be a factor in the changeup's lack of effectivity, and of course isn't doing the fastball much good either.
The fact that Hellickson has yet to build up his velocity back to normal is a bit concerning as we approach June. Although he's pitcher who pitches to contact and isn't known for fastball velocity, getting his fastball back up to 92+ MPH is crucial if he wants to return to 2011/2012 form.