The Angels’ bullpen was a mostly unremarkable bunch in 2018, with the group finishing 20th in the majors in Wins Above Replacement. That explains why the team has been searching for bullpen help this winter. According to reports, for instance, the Angels were “runners-up” in the Zach Britton sweepstakes and have been exploring trades for the Giants’ Tony Watson and Will Smith. They were also reportedly involved in the markets for David Robertson and Joakim Soria.
Given the bullpen’s forgettable overall results, the Angels are, of course, right to prioritize relief upgrades. Fortunately for the club, though, its bullpen is only in need of reinforcement rather than a complete makeover, as the Angels now have a solid base of relief talent to build upon that includes players like Hansel Robles.
After spending the entirety of his career with the Mets organization, Robles, now 28 years old, joined the Angels on a mid-season waiver claim. Robles was a useful reliever for New York for the first two years of his big-league career, posting a 3.55 ERA and 146 strikeouts across 131 2/3 innings from 2015 to 2016. However, he regressed greatly in 2017 and even further in early 2018. Ultimately, he compiled -1.1 WAR over his final 76 1/3 frames with the Mets.
Once he got to the Angels, though, Robles managed to rekindle some of his early career success. Whereas Robles permitted seven home runs in 19 2/3 innings with the Mets in 2018, he gave up just two in 36 1/3 frames with the Angels. Furthermore, he dropped his walk rate from 11.4% with the Mets to a more manageable 9.7% with the Angels and increased his ground-ball rate from 26.9% to 38.6%, which is four percentage points better than his career-high. The result was a solid 2.97 ERA and 3.22 FIP in an Angels uniform.
More than anything, Robles benefitted from a major spike in velocity when he got to the Angels. In fact, from the day he made his first appearance with the Angels (June 24) to the end of the season, no relief pitcher added more velocity to his four-seam fastball than Robles.
In 2015, Robles’ fastball averaged 96.4 mph. In 2016, it fell to 95.7. In 2017, it dropped to 95.0. And, as seen above, it tumbled even further in the early part of 2018 to 94.7. But Robles’ four-seam velocity steadily improved throughout the season, and, as seen below, it really took off near the end of the season.
July 2018, when his four-seamer averaged 96.9 mph was the second-hardest-throwing month of Robles’ career, and September 2018 is tied for the hardest-throwing month of his career, with his fastball averaging 97.1 mph.
Moreover, in terms of fastball velocity, his last two outings of 2018 were his best. His four-seamer averaged 98.5 mph or better in both, which is something he had done in only three of his previous 222 career appearances. Of the 15 four-seam fastballs Robles threw in those final two outings, all were between 97.6 mph and 100.2 mph. Across the two outings, he retired six of the eight batters he faced and, as he did in 12 of his final 13 appearances of the season, allowed zero runs.
Oddly, the increased fastball velocity did not help Robles generate many more swinging strikes with the pitch. However, opposing batters had much more trouble squaring it up. Prior to June 24, only one reliever allowed a higher slugging percentage against his four-seamer than Robles’ .680 figure.
From June 24 to the end of the season, though, only eight relievers permitted lower slugging percentages against their four-seam fastballs than Robles’ .329 mark. To put that contrast into perspective, Mookie Betts led all qualified hitters in 2018 with a .640 slugging percentage, and Billy Hamilton finished third-to-last with a .327 figure.
In addition to his four-seamer, Robles throws a slider, which, like his fastball, saw a considerable velocity bump when he joined the Angels. With the Mets in 2018, the pitch averaged 86.9 mph. With the Angels, it jumped to 88.6 mph, which is more than two mph faster than it averaged over the previous two seasons and placed 18th out of 171 pitchers who threw at least 150 sliders from June 24 to the end of the season.
In that span, opposing batters managed just a .249 expected weighted on-base average versus Robles’ breaking ball, a significant improvement over 2017’s .319 mark. Additionally, with the Angels, opposing batters chased Robles’ slider 22.2% of the time it was not in the strike zone, up from 16.7% with the Mets earlier in the year. Exploiting this tendency, Robles threw far fewer sliders in the zone with the Angels than he had with the Mets during the first few months of the season (41% Zone% vs. 47.3%), which helped him generate a 33.3% whiff rate against the pitch, an in-season bump of nearly seven percentage points.
We can see how deadly this fastball/slider combination can be by taking a look at how quickly Robles put away Rangers slugger Joey Gallo in a September outing.
First, although he missed his spot, Robles jammed Gallo with a 98-mph fastball that resulted in a weak fly ball that landed in foul territory.
Robles then locked Gallo up with a 90-mph slider that just caught the bottom of the zone for strike two.
Gallo has struck out more times than any other hitter since 2017, so punching him out is not the most impressive feat. But in that same period, Gallo has slugged .632 against fastballs, which ranks in the top three percent of players. Thus, blowing one by him like this is not terribly easy.
Robles has mostly stuck with that two-pitch mix throughout his career, but he reintroduced a changeup late last season. He never had much success with the pitch when he threw it intermittently in prior seasons, and he did not throw it enough last year to be able to gauge whether it is any better now. But it is worth noting that Robles’ changeup averaged over 90 mph in 2018 for the first time in his career and that it’s possible that the strengthening of his other pitches positively affects it.
Bullpens are weird and unpredictable, but the Angels just might have quietly pieced together a strong one. There’s Justin Anderson, whose wipeout slider made him one of the Angels’ top relievers as a rookie last year. There’s Ty Buttrey, who made an excellent first impression in his brief late-season debut in 2018. There’s Luis Garcia, whose intriguing peripheral numbers led the Angels to acquire him last month.
There’s also Taylor Cole. And Keynan Middleton. And Williams Jerez. And you can add Hansel Robles to that list. For him, maintaining his velocity will be key to repeating his 2018, and improving his changeup will be crucial to taking another step forward. The Angels still need to bolster their bullpen for the 2019 season, but one can at least understand why, with Robles and others already in the fold, the team has not been overly aggressive in the relief pitching market this offseason.
Featured image via MLB.com.