Wells and Kells: A Cutter Case Examine

Last week, in his replace on pitch combine, my colleague Davy Andrews informed a story as previous as time (or at the least 2008, when the pitch-tracking period started): fastball utilization is on the decline, largely to the good thing about sliders (and sweepers). But this 12 months, there’s a brand new wrinkle: cutter utilization is on the rise, too.

Per Statcast, pitchers are turning to cutters greater than they’ve in any season since 2008. That utilization remains to be at simply 7.6%, however the year-over-year leap of 0.7% is the second highest on file. Plus, as Davy and the oldsters over at Prospects Live put it, quite a lot of the cutter’s worth lies purely in its mere existence; it doesn’t have for use a ton to be a worthwhile providing. That’s as a result of, out of a pitcher’s hand, the cutter bears resemblance to each a fastball and a slider. When pitchers are struggling to tunnel their heater and slide-piece, the issue may be that there’s just too giant a motion and/or velocity hole between the 2 choices — one {that a} cutter can bridge. As lengthy because the hitter has to assume not solely in regards to the dissimilar fastball and slider, but in addition a cutter, it may well make a giant distinction, even when the cutter doesn’t present up all that always.

Along these traces, horizontal motion gaps between fastballs and sliders have solely grown within the age of the sweeper. The new “riding slider” additionally tends to have bigger platoon splits than different related breakers, which is the place the cutter can come in useful but once more on account of its relative platoon neutrality.

The cutter doesn’t work wonders for each pitcher, however guys like Tyler Wells and Mitch Keller, each of whom didn’t throw one in any respect final season, may be having breakouts due to it. Let’s check out Wells first, as a result of I do know from watching him in opposition to the Yankees over the previous two seasons that he’s a superb instance of what I’ve been going over up to now. Here’s what his pitches of curiosity (he additionally throws a curveball and a changeup) have carried out this season in comparison with final, per Alex Chamberlain’s pitch leaderboard (motion is induced, w/o gravity, in inches), with run values per Baseball Savant:

When hitters make contact, they’re touching up the brand new cutter, which Wells has launched on the expense of his sweeper (he’s hardly thrown the whirly in any respect this 12 months) and slider. But in response to Savant, the cut-fastball has been impartial by run worth because it’s gotten a ton of referred to as strikes. Whether or not that may proceed is difficult to say; even when it doesn’t, it’s most likely value holding onto the cutter as a result of it’s doubtless helped the four-seamer carry out quite a bit higher. The heater has seen a close to 3% improve in swinging-strike fee, and Savant has it saving Wells six runs on the season whereas final 12 months it price him 5.

Speaking of final 12 months, Wells was seemingly attempting to have his slider, which was extra of a cutter/slider hybrid, bridge the hole between his sweeper and four-seamer on the time. My guess is that the previous slider was nonetheless too completely different from the four-seamer; the vertical separation was simply too giant. This 12 months’s cutter, however, stands firmly between the heater and the slide-piece by way of rise, made potential because of the slider drifting extra towards the gyro-end of the spectrum with 12% much less lively spin and 4.5 extra inches of drop. Despite the lower in CSW%, the slider is performing barely higher than final 12 months on a run-value rate-basis in response to Savant (which stubbornly labeled the pitch as a cutter final season).

The thought behind Keller’s repertoire adjustments is identical: he’s additionally clearly attempting to bridge the hole between his sliders and his four-seamer. But he assaults hitters from east to west:

While Wells is primarily a north-to-south man (nicely, largely a north man now that his four-seamer is so good up within the zone):

Keller employs his technique as a result of he will get wonderful horizontal break on his pitches, and Wells rolls out his gameplan as a result of he will get nice experience on his choices. We’ve already been over the latter, however take a more in-depth have a look at the previous’s repertoire to see what I imply (once more, sans the curveball and changeup):

Both hurlers navigated final season with a sweeper and slider in tow, and each added a cutter this 12 months. But whereas Wells scrapped his sweeper to make room, Keller removed his gyro slider. This tracks with their respective pitch instructions: the gyro slider works for Wells as a result of it assaults hitters on the vertical aircraft, and the sweeper is sensible for Keller as a result of it dodges bats on the horizontal aircraft.

For Wells, having a cutter that’s threaded the vertical-movement needle between his four-seamer and slider has been sufficient. Keller has used a cutter like that, too; its rise is extra squarely in between that of his fastballs and his sweeper than his slider was final 12 months. But not like Wells, the east-to-west Keller has a cutter that additionally has horizontal break in between that of his four-seamer and his most important breaker this 12 months. If it didn’t, that would trigger main issues for the pitch’s slot in his repertoire; Wells is doing simply superb with out goldilocks-zone horizontal motion on his cut-fastball.

At the identical time, whereas nonetheless in between his four-seamer and sweeper’s horizontal motion, Keller’s cutter truly leans meaningfully nearer to at least one facet (the four-seamer) than the slider that he scrapped for it. But the cutter is nearer to equidistant between the sinker and sweeper than the slider was, which is extra vital for him provided that the sinker and sweeper comprise one of the best pair for tunneling; each their spin axes and noticed actions are near the perfect 180 levels aside:

Keller’s sweeper has truly price him runs this 12 months, however its swinging-strike fee has shot up almost three %. Meanwhile, each his sinker and four-seamer have improved dramatically by CSW% and run worth per 100 tosses. Not to say that the cutter itself is performing rather well, with higher CSW and barrel charges than the slider he scrapped for it.

Another motive for Keller’s enchancment this season has been elevated horizontal motion throughout the board; he’s added almost two inches of run/break on every of his fastballs and his sweeper. On Tuesday evening, he struggled to corral this additional motion, throwing up a clunker in opposition to the lowly A’s with 4 walks and only one strikeout. That begin nonetheless hasn’t made it into the pitch leaderboard for my perusal, nevertheless it was the primary time he walked greater than two since his first outing of the season, so I don’t assume his early-career management points have returned. But maybe, amidst a little bit of a dry spell, now could be the time for the Pirates to signal the right-hander to a long-term deal; the changes he’s made this season make me very assured in his future.

Wells I’m a bit much less bought on, particularly since he didn’t have a lot of a prospect pedigree. He’s additionally benefitted from some main BABIP and strand-rate luck this season. At the identical time, whereas some regression is actually so as, the ground at this level remains to be a serviceable rotation possibility, one thing that the Orioles — homeowners of the Twenty sixth-worst starter WAR this season — are in dire want of.

If Wells continues to search out success, it can go a great distance towards reminding analysts that the cutter isn’t only a sweeper complement; within the tall right-hander’s case, it’s been a sweeper alternative. With some making the case for a splitter over a cutter as a platoon-neutral complement to the sweeper, the cutter’s success impartial of the whirly would possibly even stave off its extinction sooner or later.

Stats are as of end-of-day June 5 except in any other case specified.