Ariel Miranda’s Controlled Chaos

With his five-inning effort yesterday night, Ariel Miranda has now allowed two runs or fewer in eight of his eleven starts. Outside of his eight-run implosion in Philadelphia, he’s been remarkably consistent this year. Remember when Miranda didn’t even make the rotation out of Spring Training? You could make an argument that he’s been the most valuable starting pitcher for the Mariners this season.

Figuring out Ariel Miranda is particularly difficult because he’s spent the majority of his professional career in Cuba. He defected three years ago and has accumulated just 287 innings in affiliated baseball in the US. Famously, he led the Serie Nacional in strikeouts the year before he defected. He’s finally showing some of that skill in the majors this year. Miranda has increased his strikeout rate by two points, up to 21.1% this year. That improvement is fueled by higher whiff rates across all three of his pitches.

A side note first: it seems like the pitch tracking systems (specifically PITCHf/x) have a particularly difficult time classifying Miranda’s secondary pitches. We know he throws a split/change and a slider but Brooks Baseball is misclassifying his slider as a splitter and his splitter as a changeup with a lot of overlap between them. He throws them both at relatively close velocities and their movement profiles are similar enough that the algorithm has trouble determining what’s what. Statcast classifies his secondary pitches as a splitter and slider so I think they’re at least a little more accurate. I’ll be using Baseball Savant data throughout this article.

Back to Miranda’s arsenal. This season, he’s throwing his slider far more often. He’s generating a whiff almost 40% of the time an opposing batter swings at that pitch, a rate well above league average. That whiff rate is also well above what he was generating off his slider last year. Combine that increased effectiveness with his excellent splitter and you’ve got two pitches that provide a solid foundation for a great strikeout rate.

His secondary pitches also give him the means to manage contact against him. His “rising” fastball leads to a high fly ball rate, the 10^th highest among qualified pitchers this year. That’s led to some trouble with the home run but just two of the ten home runs he’s allowed have come with runners on base. That may come as a surprise considering his high walk rate but he’s actually been pretty good after allowing baserunners. Opposing batters seem unable to square up his secondary pitches and that’s helped him become an excellent contact manager.

Below, you’ll see a table with batted ball stats for each of his three pitches drawn from Baseball Savant.

As you can see, the average exit velocity off his splitter and slider is well below league average (~88 mph). The rate of hard hit balls in play for those two pitches is much better than it was last year and reflects an ability to generate desirable contact. He’s generating a pop up with his secondary pitches as often as he’s allowing a line drive. That’s helped him post the fifth lowest line drive rate and fourth highest infield fly ball rate among qualified starters. With those things in mind, it’s no surprise his career BABIP is just .238 and an excellent .255 this season.

Miranda doesn’t come without some warts. His control is less than ideal and he has serious trouble going deep into games. When he faces a lineup three or four times in a game, his ERA balloons to 7.59. There isn’t much that changes in his pitch mix as he gets deeper into games. His walk rate jumps up to 18.4% when facing a lineup for the third time which could indicate some fatigue issues. His velocity doesn’t drop too much the later he gets into a game so it’s possible these problems are only linked to a loss of control.

A few starts ago, Bill Krueger was asked on the TV broadcast to come up with a pitcher to compare Miranda to. He was cut off by Dave Sims and the end of the inning before he could answer but thanks to Twitter we’ve got an answer: Jeff Fassero. That’s an interesting comp but when Kate asked the LL staff the same question, I came up with a more modern comp: Matt Shoemaker. Like Miranda, Shoemaker’s arsenal consists of a fastball, a splitter, and a slider (with the occasional curveball thrown in as well). Their batted ball profiles are fairly similar as well. Shoemaker has better control and throws his splitter much more often than Miranda but there are some definite similarities. Like other contact managers with a high fly ball rates, their ERAs will consistently outperform their defense independent pitching estimators. Shoemaker probably has a higher ceiling because of his elite splitter. But make no mistake, Miranda has been an incredibly valuable piece for the Mariners and has pitched well enough to make filling out a healthy rotation a difficult decision for Scott Servais.