At this moment, the Arizona Diamondbacks, those same Diamondbacks who went into “win now mode” this offseason, currently sit in fourth place in the NL West division. The D-Backs’ pitching has specifically underwhelmed this year. However, one starter on their roster stands out to me, one who was not much more than an afterthought on their staff at the beginning of this year. That man is Robbie Ray. He has 10.42 K/9! That’s good enough for 9th in the MLB amongst qualified starting pitchers–ahead of Madison Bumgarner, David Price, and Jake Arrieta (to name a few). He struck out eight guys in five innings his last time out. But, his ERA sits at an unimpressive 4.59. What’s up with Robbie Ray? Let’s take a look.
Let’s start with his four seam fastball. Its velocity has risen each season since he first came up in 2014.
He has topped out at 97.6 this year–great for a lefty. He averages 93.6 on the heater, which is harder than all other qualified lefties this season. Its SwStr% has gone from 7.1% last year to 8.3% this year–a very high SwStr% for a fastball. The pitch even has a bit of armside run and added backspin, giving it a “rising” appearance. He throws his fastball 59.6% of the time (3rd highest in the majors), and for good reason.
His slider is solid. Hitters are managing a meager .570 OPS against it. It has an 18.4% SwStr%, up 0.3% from last year. Here is a wonderful gif of Ray striking Andrew McCutchen with the slider:
And him striking out McCutchen again:
Not to mention, the pitch is generating a whopping 67.6% groundball rate this season.
So both the fastball and slider are solid pitches. But here is where Ray runs into some trouble: his two-seamer is mediocre and his changeup is awful.
He throws the two-seamer hard, and consequentially, it has less movement than average. It has slightly more movement than his four-seamer, but otherwise, it’s just a slower version of the four-seamer with much less “rise”. Last year, it did generate a solid 54% GB%, but this year, that number has dropped to 44.7%. Hitters are mashing it to the tune of a .962 OPS this season, though last year they only managed a .729 OPS in a similar sample size. That withstanding, the SwStr% of the pitch has jumped from 6.1% last year to 7.1% this year, probably because his improved fastball and slider help to set it up better.
The changeup is awful: hitters currently have a 1.437 OPS against it this year. But, last year, hitters only had a .662 OPS in a similar sample size. He has trouble commanding this pitch, especially: he throws it for a strike only 53% of the time. However, there is some good news: the SwStr% has almost doubled, going from 4.6% to 8.5%.
Having examined Ray’s repertoire, I have a couple of predictive theories. Firstly, his HR/FB ratio is an exceedingly high 16.7%. This is well above the league average and his career rate of 10.9%. According to park factors on ESPN and Fangraphs, Chase Field is at least in the top 5 in terms of worst parks for pitchers, so that could explain some of this. He also overperformed with a 7.3% HR/FB rate last year, and maybe this is just regression coming in. Either way, I think that this rate should certainly improve through the rest of the season, settling in closer to his career average rather than 16.7%. Unsurprisingly, the changeup is the main culprit here; it has a 100% (!) HR/FB rate. This should almost certainly regress, which would bring his “OPS against” on the changeup back down.
Something else of note is that the changeup and two-seam fastball are weapons primarily deployed against batters of the opposite handedness, as they would move away from the batter. Since these are Ray’s two poorest pitches, it makes sense that he struggles to get right handed batters out. They have a .875 OPS against him, compared to the meager .590 OPS that lefties manage. The changeup and/or two-seamer need to improve for Ray to start getting right handers out. These two pitches have been hit hard, and have thus helped to make Ray’s BABIP climb up to .350. The BABIP against his changeup is .476 and against his two-seamer, it’s .421.
One last thing that should not be discarded is that Ray’s walk rate has risen this year. Poor command of his pitches has resulted in him leaving a few meatballs over the plate. The fact that he only throws his changeup for a strike 53% of the time is specifically a major detriment to his control; the rest of his pitches are at least at 59.9% or higher.
So, Ray’s HR/FB rate should at least regress a bit, and I think that he can get his ERA under 4 for this reason alone. Roll with the Steamer projections for the rest of his season over ZIPS, but keep in mind neither projection system knows of Ray’s velocity increase and improved SwStr%, so it’s entirely possible that he can do even better, maybe even sustaining a 10 K/9, especially if he can improve his command and work on his changeup and two-seam. To sum it all up, the SwStr% has improved on all of Ray’s pitches, and there’s room for improvement yet; he’s only 24 years old.
Written by Alex Eisert