It was a bag of mixed results for Heath Fillmyer in his first major league season. Coming off a successful stint in double-A last year, a trade, and a big league spring training invite, he looked to continue his rise as a prospect with a good showing in Omaha. The exact opposite of that would end up happening, as Fillmyer would show a lack of consistent command and control, something that is especially hard to get away with in the hitting confines of the Pacific Coast League. So with a 5.75 ERA at the Triple-A level, you’d figure any sort of success for Fillmyer at the Major League level would be welcomed.
The 4.26 ERA Fillmyer posted in 82.1 innings with the Royals was a good start in the sense of actual results. It didn’t necessarily reflect his actual level of play, which with his low K-rate and high BB-rate, probably was closer to an ERA in the fives. It’s almost nearly impossible to make it as a big league starter with a single digit K-BB%, so if the peripherals don’t improve for him, it’s going to be tough sailing from now on. Regression will inevitably come.
If you look even deeper past the peripherals, you’ll find the positives in Fillmyer’s debut season. All three of his secondary offerings showed above-average results, something that is pretty rare to see. The problems drew off his lackluster fastball and again, inconsistencies in command. While watching Fillmyer earlier in the season down in Triple-A, you could see the makings of a big league starter in a few select games. If he was throwing his secondaries where he wanted, he was having success. If not, which happened a fair amount, he was getting lit up all over the ballpark. I pointed this out in my evaluation of him back in late July.
In a game that summarized the ugliness of the 2018 Royals in one inning, one of the few positives that stood out was the performance of Heath Fillmyer. He left little to be desired with his performance in AAA, showing extreme inconstancies with command and control. Mixed in his overall lackluster performance though were a few starts that showed his capabilities of becoming a viable major league starter, such as...
April 15: 5.1 IP, 2 H, 0 R, 0 ER, 1 BB, 4 SO
April 20: 6 IP, 3 H, 0 R, 0 ER, 1 BB, 6 SO
May 22: 7 IP, 4 H, 1 R, 1 ER, 3 BB, 3 SO
June 7: 6 IP, 3 H, 2 R, 2 ER, 3 BB, 9 SO
I think we saw a lot of this at the next level too. You’d see starts where Fillmyer was walking guys, having trouble inducing whiffs, and allowing hard-contact, while you’d also see starts where he’d command the ball in the zone, load up on the swinging strikes, and get hitters to punch the ball softly into the ground. Over a third of his starts had swinging strike rates greater than 11 percent, something that doesn’t usually fit with a high-contact pitcher. Conversely, he had three starts in there with a sub-six percent rate.
As I said, the repertoire showed some good results through the course of the season. All three of Fillmyer’s secondaries graded positive prorated pitch values, per FanGraphs. Only 14 pitchers with 50 innings as a starter did that this year, a group that includes names like Jacob deGrom, Trevor Bauer, Mike Foltynewicz, and Clayton Kershaw.
List of pitchers with positive grades with their slider, curveball, and changeup
The issue now lies in the fastball. Among 334 pitchers with 500 fastballs thrown this season, Fillmyer ranked 309th in swinging-strike rate, sitting at 5.0 percent.
With a glut of possible back-end starters fighting for an Opening Day rotation spot next year, Fillmyer will have to show improvement is his underlying peripherals to stick around. The initial results might not have been pretty (also worth mentioning he’s only been pitching since 2014), but at least we know there might be something there with the trio of average to above-average secondaries. He’s flashed this success too, he’ll just need to show it more often.