Keegan Thompson Made Sweeping Changes

Pitches are arduous to categorise, and the interactions between them are much more fraught. Combine up a slider and a cutter, and also you’ll make the aggregates look all — wait, I began too particular. Let’s again up. Baseball is a sport performed between two groups, every of whom take turns making an attempt to hit a ball thrown by the opposite group utilizing a bat. The thing of the sport is to advance safely — wait, now that is too common. Let’s see if we are able to hit a contented medium.

Keegan Thompson throws a number of pitches. Relying on the way you rely them — and boy, will we get into the way you rely them on this article, don’t fear — he throws as many as six totally different pitches, all with distinct properties in a method or one other. Want a grounder? Keegan has a pitch for that. Strikeout? Positive factor. Need to beat a lefty, or induce a pop up, or regulate native energy vegetation? Thompson can do the primary two of these, if he picks the appropriate pitch for the appropriate state of affairs.

This yr, it appears to be like like that earlier paragraph is barely partly hyperbole. In his 2021 main league debut, Thompson primarily labored out of the bullpen and had blended success. He struck out a median variety of batters but in addition ran a stroll fee of practically 13%. He went into 2022 with out a clear position on the group — we projected him for just a few begins and loads of bullpen work — however with a urgent want for enchancment on the command entrance.

Within the bullpen, Thompson largely relied on his four-seam fastball, cutter, and curveball. He blended in a particularly occasional changeup — 12 of the 620 pitches he threw in aid — however for probably the most half, he caught along with his bread and butter. That is sensible. They will’t all be his greatest pitch, and when you’re solely throwing one inning per sport, you would possibly as effectively follow the bread and butter — in his case, the excessive cheese.

However tinkerers wish to tinker, and in his new beginning position, Thompson explored the studio area. At first, he did it in suits and begins. He caught to his fastball/cutter/curveball strengths, mixing in a handful of changeups and sinkers in each begin. Then, in his final three begins, he began throwing a slider from time to time. The slider doesn’t grade out notably effectively by Pitch Data, and he doesn’t throw lots of them, however fortuitously, his cutter and four-seamer acquired a lot better, and similar to that, Thompson was a wonderful starter.

Or, effectively, that’s the way it goes when you take a look at varied pitch classification websites. The truth isn’t fairly so easy. The truth that he’s throwing a brand new slider is definitely true; MLB.com’s Jordan Bastian wrote an excellent story on the pitch this week. Thompson and the Cubs needed a brand new pitch to complete at-bats, and it’s arduous to overlook the impression that sweeping sliders have had on the sport. He discovered the pitch throughout bullpens — aspect observe, wow is that spectacular — and began throwing it three begins in the past, on June 17.

To date, so good! We’ve lined all that already. Bastian’s article additionally lays out a number of the outcomes: iffy location, however glorious bat-missing means. Thompson talked about the necessity to management the pitch higher — per Pitch Data, it has a zone fee of 12.5%, so he’s not improper — however praised its motion and sounded enthusiastic about utilizing it sooner or later.

Now let’s get to the complicated half. In those self same three video games, Thompson’s cutter improved markedly. It began lacking extra bats. Contact towards it acquired worse. The identical factor occurred to his four-seamer, a minimum of considerably; the contact information is blended, however it’s definitely lacking extra bats.

We will depart the four-seamer apart for now. As greatest as I can inform, that comes down to raised location. Check out this time lapse of four-seam location earlier than his current good stretch and through it:

Okay then! Increased four-seamers, revenue. That’s simple sufficient to know. And he’s finding his cutter nearer to the perimeters as effectively — most likely not sufficient to elucidate the extent of its enchancment, however nonetheless a tailwind. Nonetheless, Thompson added a brand new pitch, and his outdated ones all of a sudden acquired higher. Is there one thing to it?

Let’s attempt one other concept. Is Pitch Data (which drives these location charts I simply used) mis-classifying his new sweeping sliders as cutters a number of the time, resulting in a mis-match in what we’re measuring? Because it seems, principally no. One of many neat and under-appreciated instruments on FanGraphs is the pitch graphs tab, the place you may escape velocity, motion, and launch level by pitch sort. With maybe one or two exceptions, the slider and cutter seem like distinct and accurately categorised pitches:

And, effectively, if that’s the case, then the cutter is kind of the identical earlier than and after Thompson added a sweeper:

In truth, when you strip out the 2 probably mis-classified cutters, there’s been no change in velocity and a negligible change in vertical motion. The one distinction is barely much less horizontal motion, and that doesn’t sound like a good way to elucidate how the pitch acquired higher.

I’ve a guess, however I wish to be clear that it’s only a guess. Mainly, I feel that including a slider has freed up Thompson’s different pitches for use in conditions the place they shine. Take into account: earlier than he added his slider, he threw both a cutter or curveball 50% of the time in 0–2, 1–2, and a couple of–2 counts, or, in different phrases, counts the place he was searching a strikeout and will afford to waste a ball. In his final three begins, that quantity has plummeted to 29% per Statcast, and it’s extra like 23% if you account for classification points.

That’s not an enormous distinction within the mixture. Thompson has thrown 16 (or extra, Statcast’s classification isn’t as clear as Pitch Data’s right here) such two-strike sliders in these most up-to-date begins; we’re not speaking about an amazing variety of pitches right here in any respect. However I don’t discover these counts conducive to cutters, a minimum of not the sort of cutters Thompson throws. As assistant pitching coach Daniel Moskos instructed Bastian, “when you’re searching for swing-and-miss… to righties, you want one thing that strikes a little bit extra horizontally.”

Positive, that’s in response to a query concerning the new sweeper, so horizontal break was absolutely on his thoughts already, however when you’re particularly seeking to miss bats, extra motion is best. As an additional benefit, having the slider as an choice most likely helps the cutter play up. Each pitches function a ton of gyroscopic spin, which helps to disguise them out of his hand, and so they’re solely 5 or so miles per hour aside. Regardless of that, the slider drops practically a foot extra on its path house — thanks, gravity — and strikes 4 or so extra inches horizontally. If you’re seeing cutter after cutter all through the day, a similarly-spun pitch that dives down and away can’t be simple to adapt to, and realizing the following pitch could possibly be a sweeper does you no favors in hitting a cutter both.

Thompson hasn’t thrown sufficient sweepers for me to really feel comfy measuring this impact. I’m truthfully undecided I might decide it up even when he’d thrown 10 instances as many; deciphering the interplay between pitches is without doubt one of the hardest analytical challenges within the sport. However I definitely don’t suppose it hurts. And even when that isn’t the case, utilizing his cutter in better-suited counts can clarify a number of the advance by itself.

In case you surrender contact in a two-strike rely, you’re forgoing an opportunity to strike somebody out. Irrespective of how good you might be at suppressing contact, letting a two-strike rely cross by with out a strikeout is a foul deal. Just like the conundrum that sinker-heavy pitchers face, Thompson was struggling a strikeout scarcity. He couldn’t maintain his four-seamer excessive, and he didn’t miss sufficient bats along with his cutter to make up for it.

That scarcity has changed into a surplus in his final three begins; he’s struck out precisely one-third of the batters he’s confronted. I don’t count on that fee to proceed — his peripherals don’t help it, with a swinging strike fee of solely 13.6% — however I do count on him to put up above-average strikeout numbers the remainder of the yr.

Maybe most fun? Thompson has achieved all of this with out his sweeper being notably good. He hasn’t refined its management in any respect; he’s thrown 24 of them, and 14 have been within the “waste” zone. A few of these have labored, however you may’t at all times face the Reds:

If he begins to hone his command of the pitch, higher days is perhaps forward. Not higher than his final three begins — I don’t suppose he’s a true-talent 2.45 ERA pitcher — however higher than his blended 2021, and higher than the lengthy reliever position he began the season with. As an added bonus, including the slider makes the graph of Thompson’s pitch motion fairly fairly:

For Thompson and the Cubs, 2022 is a season of discovery. There gained’t be playoff video games on the finish of the yr. There is perhaps empty seats in September, and there’ll virtually definitely be trades with a watch towards the long run on the finish of July. However discovering one thing new is a superbly good purpose to play baseball, and along with his new sweeping slider and all of a sudden improved command, Thompson appears to be like to be heading in the right direction.