Treating Ariel Miranda’s Dingeritis

Dingeritis—loosely defined as an inability to keep fly balls in the yard—plagued Major League Baseball’s pitchers last year. The league total for home runs leapt by almost five hundred more than in 2016, despite an uptick in ISO of just around ten points. Few staffs were bitten harder by the homer bug than the Mariners, who gave up the fourth-most in the league at 237, trailing only the Orioles, White Sox, and Reds —three teams that play in bandboxes relative to Safeco. Not exactly the most esteemed company there.

One Mariner, though, had an especially severe case. Ariel Miranda gave up a whopping thirty-seven home runs last season, trailing only Rick Porcello, and was responsible for about fifteen percent of all homers given up by Mariners pitchers. He did manage to avoid the long ball in nine starts out of 29, but he allowed multiple dingers in twelve others, including a brutal outing against Baltimore at the end of August in which he surrendered four. Throw in his merely decent strikeout and walk numbers and the fact that he’s entering his age-29 season, and it’s easy to understand why many fans breathed a sigh of relief when Miranda didn’t open the season with the big club.

It would be brash to write him off completely, though. Miranda’s raw stuff can impress; his fastball touched 96 MPH at times last year, and his splitter, changeup, and slider are all capable of getting swinging strikes. Unfortunately, he leaned a little too heavily on the fastball, which is his one pitch that has a below-average whiff rate.

Brooks Baseball

Although Miranda did start mixing his pitches a little more in the second half, he threw his fastball over half the time in every month except September, peaking at nearly 63% in June. Luke wrote back in February about how both Brooks and FanGraphs have a hard time with distinguishing his splitter and changeup, but the true surprise is how little he threw his slider, which was an excellent pitch for him all season long—he didn’t allow a single extra-base hit off of it, and it generated an astounding 42.9% pop-up rate. While it was used more and more in the last two months of the season, its lack of use is still puzzling given how efficient it was at inducing weak contact and whiffs.

Brooks Baseball

August saw the highest whiff rates for both the splitter and changeup, with the change especially seeing a bump up of almost ten percent. While the fastball’s whiffs dropped from July, this graph looks encouraging. How did this translate on the field?

Well...

Brooks Baseball

FanGraphs

Oof. Although Miranda’s changeup started getting more whiffs as the year went on, when batters connected with it, it tended to get hammered; its ISO against never dropped below .200 until September, when Miranda curiously didn’t give up an extra-base hit off of it. What unexpectedly stood out to me, though, was the fact that his fastball got smacked even harder in August, to the tune of a .600 (!!!!) ISO against.

Let’s jump back to the four-homer start that was mentioned earlier. Three out of four of the dingers given up that day were off of the fastball, and the fourth was off the split. Here are some sequences to feast and/or avert your eyes on.

MLB.com

MLB.com

MLB.com

MLB.com

With the possible exception of Craig Gentry (seriously?!), all of those pitches were cookies. The first-pitch dinger—on the split, no less—to Schoop was especially egregious, with Zunino setting up here...

MLB.com

...and the pitch ending up here:

MLB.com

Miranda also lost a lot of command in September, walking ten guys against just eight strikeouts, although this could possibly be attributed to fatigue; he set a new career high in innings pitched at 160 last season. His swinging strike rates fell across the board, and he managed just 9.2 innings that month, capped off by a dreadful relief performance against Cleveland. If there’s one silver lining, though, it’s that his velocity stayed consistent all year, even when he struggled.

Brooks Baseball

Despite his advanced age and up-and-down 2017, Ariel Miranda still has upside. Three out of four of his pitches are adept at generating whiffs, his durability was a very pleasant surprise to an injury-ravaged rotation, and he still has four years left of team control after 2018 - with options left to boot. While he would ideally spend more time in Tacoma fine-tuning his pitch mix and sequencing, the M’s are going to need a fifth starter by April 11th, and either Miranda or Rob Whalen seem most likely to get the call if Erasmo Ramirez isn’t ready. Should they opt for Miranda, his fastball usage and secondary command will be the main things to keep an eye on. If he can optimize both of those, and start throwing his excellent slider more often, he stands a good chance at recovering from dingeritis and being a reliable option for the next couple of years.