Underthrown Pitches And The Pitchers Who Underthrow Them: Vol. 3 Sliders and Changeups

Welcome back to the third and penultimate installment of Underthrown Pitches and the Pitchers Who Underthrow Them. Over the last several weeks, we’ve identified high performing four-seamers, sinkers, cutters, and curves and the pitchers who should consider throwing them more often. We’ve defined “high performing” based on a Pitch Score that factors an offering’s proclivity towards inducing whiffs, ground balls, and pop-ups. We’ve also defined the degree that a pitch is “underthrown” using a simple measure of pitch score to frequency.

For a more detailed recap of the results and methodology to-date, check out the previous installments linked below.

Vol 1: Four-seamers and Sinkers

Vol 2: Cutters and Curves 

Sliders

So half of the league’s most underthrown sliders belong to starters currently on the disabled list or toiling away in the minors. Between Danny Salazar (shoulder), Trevor Cahill (shoulder), Dallas Keuchel (neck), Noah Syndergaard (lat), and Blake Snell (minors), we’re missing out some of the league’s very best sliders. But that doesn’t mean there aren’t others worth talking about.

Others, such as Ariel Miranda. Undoubtedly, Seattle’s other lefty has been plagued by too many homers. He’s currently giving up 1.70 dingers per nine innings but that tendency does not necessarily appear due to any bad luck. Rather, he simply gives up a debilitating number of fly balls. In fact, Miranda’s 49.0% fly ball rate is the highest in the league and while the Mariners boast the league’s best outfield defense, it’s a tall order for anyone to catch balls on a trajectory for Safeco’s bullpens. Throwing a few more sliders might rectify that.

Miranda’s slider induces grounders on 50% of balls-in-play. That’s good enough for 37^th out of 118 qualifying sliders. However, it’s the combination of grounders and pop-ups that really sets it apart from its peers. Earning a weakly hit pop up on 13% of balls-in-play, Miranda’s slider ranks 15^th in terms of contact management. Sure enough, hitters have managed just a handful of singles and a .097 True Average against the pitch, which ranks third among the league’s sliders in a tie with Corey Kluber’s. Nice company to keep.

So given this information, you might be forgiven for thinking Miranda’s pitch is just a really effective weapon for managing and neutralizing quality contact. The thing is, he’s also getting a ton of whiffs with it too. Its 45% swing-and-miss rate ranks 18^th in the league despite the fact that it possesses below average velocity and run. This may be a case where the pitch’s effectiveness is a function of its paucity and that throwing it more often might diminish the element of surprise. However, it’s not getting called for strikes very often. Rather, hitters swing frequently and simply miss it so it’s not abundantly clear that hitters freeze in shock when they see it. Given that effectiveness thus far and that Miranda’s problems stem from an abundance of homers, he should lean on any offering that portends more infrequent and weaker contact.

Despite ranking sixth in the league in Slider Underthrown Index, Adam Conley might not actually want to throw his slider more often. Rather, he should pick his spots a little more selectively. His issue this season has been a complete lack of control. Conley is walking over five batters per nine innings so leaning on a pitch with a 35.5% Zone-percentage and 27.5% chase rate might not be the best idea.

Still, it’s the best slider in the league by ground balls-plus-pop ups. Conley should consider himself lucky that he’s maintained a league average HR/9 despite featuring what would amount to the league’s 13^th worst ground ball rate had he the innings to qualify. He should therefore also consider throwing a few more sliders at the expense of his changeup, which is excellent at inducing whiffs but similarly difficult to control. Throwing his slider early to generate ground balls while opting to finish hitters off with his changeup in two-strike counts seems a more appropriate mix.

Eno touched a bit on Mike Bolsinger’s slider in a piece last week that, of course, you should read. Bolsinger is having a lousy year. Yes, his strand rate should regress and he’s great at generating ground balls but unfortunately he’s also the single most capable ball four enthusiast in the league. Literally. There’s nothing fantasy-relevant about Bolsinger, especially considering he’s currently pitching for AAA-Buffalo.

Still, you can’t blame his troubles on his slider, which by almost any measure has been one of the best in the league. The pitch ranks 34^th out of 118 in whiffs per swing and 3^rd in ground balls-plus-pop ups per ball-in-play. And opposing hitters have been unable to muster an extra-base hit against it. It also has excellent run and above average drop making it both an exceptionally difficult pitch for hitters to square up but also for Bolsinger to command. And, as with Conley, therein lies the rub. How does a starter leading the league in walks justify leaning on a pitch that earns one of the league’s worst called strike-to-ball ratios?

Command (and a call-up) seems to be all that stands in the way of Bolsinger adding a devastating weapon to his arsenal. But given his history of league average command, I’ll gladly take a flier on Bolsinger is dynasty leagues. Armed now with multiple breaking pitches, one of which has the potential to be elite, he makes for an excellent sleeper should he regain the command he’s previously shown capable of over the course of his career.

Changeups

When I introduced this series three weeks ago, I used Tyler Chatwood’s changeup as an example to explain how this analysis might be applied. I have to admit, I didn’t expect that by the time I got around to covering changeups, that he’d still be atop the leaderboard. Chatwood’s changeup continues to be that good. And frustratingly, he still refuses to throw it. In fact, it appears he’s thrown it less frequently over the last few weeks as his Change% has decreased from about 7% to 5.8%. And I’m not exactly sure why.

Chatwood’s change ranks 20^th in whiffs per swing and 1^st in grounders-per-ball in play, while sporting a .000 isolated slugging and .137 True Average against. Averaging 88.62 mph, it’s also one of the hardest changeups in the game. Now, Chatwood complements it with a four-seamer that averages a little over 95 mph and that ~7 mph differential doesn’t rank favorably relative to the rest of the league. Perhaps that’s why, despite excellent results and the peripherals to support them, Chatwood doesn’t yet feel comfortable flashing his change piece more often. Still, all evidence suggests that he should and he should do so quickly.

Zack Godley has been a revelation this season. Since bursting into 2017 with some additional heat, Godley has mowed down opposing lineups with a deadly combination of strikeouts and ground balls. He’s been excellent in large part due to his changeup, which he now throws with a little more gas. It’s the fourth best changeup in terms of whiffs, keeping truly elite company behind Syndergaard and Stephen Strasburg and ahead of Sean Manaea.

He’s also inducing grounders with it on nearly three-quarters of the balls put into play. By Pitch Score, Godley’s change trails only Strasburg’s and Kluber’s. Hitters have mustered just a single extra base hit off it, a double, and with a 27.59% Put Away % that ranks 8^th among the league’s changeups, it serves as an elite out pitch as well.

On average, pitchers who throw a changeup frequently enough to qualify for this exercise throw the pitch 15% of the time with a standard deviation of about 7%. Godley only slings his on 12.4% of his pitches meaning he could conceivably throw it far more often than he is now and still rank well within a reasonable distance from the mean.

I ignored Mike Leake in the slider section. But given that he’s also making an appearance on the list of underthrown changeups, I can do so no longer. Despite the excellent season he’s having now, could Leake actually be even better by throwing more sliders and changeups? If he wants more whiffs, he should throw his slider more often. If he’s looking to add to his ground ball rate that already ranks 8^th among qualified starters, he should look towards his changeup. Either way, both pitches perform far better in terms of whiffs and grounders than his cutter which he throws over a quarter of the time, so the fix, if even necessary, seems obvious.

Now, at the beginning of the article I mentioned that I’m planning one more piece in this series. I did so not because I have any real interest in covering the league’s underthrown splitters, screwballs, and knucklers, of which there are only 16, 0, and 2 pitchers respectively who even meet the qualifying criteria. Rather, given how often I came across names like Noah Syndegaard, Brandon Finnegan, and Corey Kluber, I’d like to put it all together and identify which pitchers have the largest combined Underthrown Index, suggesting they should consider not simply throwing one offering more frequently but perhaps overhauling their entire pitch mix. It also may serve as a proxy for an overall arsenal score as well.

As always, below you’ll find the complete lists of underthrown sliders and changeups.