When a baseball player who has a lengthy and reliable career track record goes through a period where his production wildly deviates from that track record, such variance is often attributed to luck.

Typically for fans surprised by unexpected short-term outcomes, that rationalization will sound something like this:

“This guy sucks. There’s no way he can keep it up.”

Or.

“I want to bathe myself in kerosene and play with matches when I watch this man perform sports-related activities. I thought he was better than this.”

Dramatic, yes. But if that second line sounds familiar, perhaps you’ve watched a Phillies game with me this season while Tommy Hunter has been on the mound.

Baseball, in particular, is a game driven by the collection of data and numbers. Indicators like batting average, for instance, have long been used to evaluate a hitter’s collective performance. Recently, the game’s decision-makers are straying from traditional metrics and increasingly focusing their attention on newer data to make assessments that may not align with what the traditional numbers suggest.

For example, let’s say a hitter is posting a .300 batting average a month into the season. Great, right? Maybe not. If that same hitter has an average exit velocity well south of the league average of 87.3 mph, and that hitter also has an abnormal batting average on balls in play, then that .300 batting average is probably largely thanks to luck.

So how does this relate to Hunter?

Prior to the season, the 10-year veteran came to Philadelphia on a two-year, $18 million deal to help solidify the back end of the bullpen. Dating back to 2013 when Hunter became a reliever on a full-time basis, he’s been one of the game’s more reliable arms. During that period, which was mostly spent in the American League, Hunter posted a 3.27 ERA, 3.41 FIP, and 1.13 WHIP, while holding opposing hitters to a .241 batting average. That’s damn good, and it’s understandable why the Phillies wanted to add an experienced and productive guy like him to the mix.

This season, however, has been a far different story for Hunter. Despite essentially maintaining consistent velocity from his previous more productive seasons, the results simply haven’t been there. The 32-year-old has a 4.80 ERA, 1.50 WHIP, and has allowed a .302 batting average to opposing hitters, while surrendering at least one earned run in 12 of his 35 appearances this season. There’s no sense in mincing words: He’s been fucking brutal.

But why?

The .372 BABIP he’s allowed thus far is greatly higher than his career average of .286, which does suggest bad luck is at least in part to blame for his poor results, but luck isn’t the lone contributing factor to such variance. Another reason could be that his pitches just haven’t been that good and have been catching too much of the plate. 

But to what extent should luck actually be used to explain Hunter’s rough season? At one point last month, both Gabe Kapler and Matt Klentak went so far as to actually suggest that Hunter was having a better season than a year ago (he’s not). Kapler cited Hunter’s pristine FIP (fielding independent pitching), which is a pitching performance metric designed to remove variables from the equation that are out of a pitcher’s control. Here is Kapler last month on Hunter, in a story from Scott Lauber of the Philadelphia Daily News:

Nobody’s going to look at Tommy Hunter and say, ‘Wow, he’s having such a great year.’ He’s actually having a better year than he had last year. Look at his underlying numbers — his strikeout numbers, his walk numbers, his FIP, his xFIP. The ERA might not be better, but those other numbers are better.

What Kapler was suggesting at the time was, essentially, that Hunter had been unlucky, whereas he previously had not been. Hunter’s career 4.36 FIP is pretty much in line with his career 4.15 ERA. On June 17, Hunter had a 1.30 WHIP and 6.7 K/BB ratio, while allowing opponents to hit .274 with a .349 BABIP. His 4.05 ERA was significantly disproportionate to his 2.38 FIP. In 20 IP, he allowed three walks and one home run, while striking out 20 hitters. Theoretically, Hunter was having great success with the outcomes he could control. The blown holds, backbreaking hits, and poor performances were just plain old bad luck, according to the manager. But if Kapler still wants to throw FIP at us to explain away Hunter’s season, he should probably come up with a different metric to defend his guy.

Since June 18, Hunter, somehow has managed to be worse. Since then, his ERA has ballooned to 6.30 and his FIP is 5.43. His deteriorating 2.3 K/BB is indicative of a pitcher striking out hitters with less frequency and walking them with more. All this while allowing hitters to post a .357 average and 1.021 OPS.

It makes sense why the Phillies brushed off Hunter’s struggles last month. The conventional wisdom is that when traditional metrics are so completely disproportionate from the peripherals that over time things will even out. In the case of Hunter, that hasn’t happened. Instead, the peripherals are rapidly getting worse. Generally, that doesn’t bode well for a reliever that already has the 12th-worst WHIP and 13th-worst ERA in the National League, and it’s a big reason why the team will almost certainly have to add another bullpen arm to the mix prior to the trade deadline.