Wells and Kells: A Cutter Case Study

Final week, in his replace on pitch combine, my colleague Davy Andrews told a story as previous as time (or a minimum of 2008, when the pitch-tracking period started): fastball utilization is on the decline, largely to the advantage of sliders (and sweepers). However 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 bounce of 0.7% is the second highest on document. Plus, as Davy and the oldsters over at Prospects Live put it, a whole 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 is likely to be that there’s just too giant a motion and/or velocity hole between the 2 choices — one {that a} cutter can bridge. So long as the hitter has to assume not solely in regards to the dissimilar fastball and slider, but additionally a cutter, it may make a giant distinction, even when the cutter doesn’t present up all that always.

Alongside these strains, horizontal motion gaps between fastballs and sliders have solely grown within the age of the sweeper. The brand new “riding slider” additionally tends to have larger platoon splits than different comparable breakers, which is the place the cutter can turn out to be 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, is likely to be having breakouts due to it. Let’s check out Wells first, as a result of I do know from watching him towards the Yankees over the previous two seasons that he’s instance of what I’ve been going over to date. Right here’s what his pitches of curiosity (he additionally throws a curveball and a changeup) have performed 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. However in line with Savant, the cut-fastball has been impartial by run worth because it’s gotten a ton of referred to as strikes. Whether or not 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 seemingly helped the four-seamer carry out loads higher. The heater has seen a close to 3% improve in swinging-strike charge, and Savant has it saving Wells six runs on the season whereas final 12 months it price him 5.

Talking 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, then again, stands firmly between the heater and the slide-piece by way of rise, made attainable because of the slider drifting extra towards the gyro-end of the spectrum with 12% much less energetic spin and 4.5 extra inches of drop. Regardless of the lower in CSW%, the slider is performing barely higher than final 12 months on a run-value rate-basis in line with Savant (which stubbornly labeled the pitch as a cutter final season).

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

Whereas 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 glorious horizontal break on his pitches, and Wells rolls out his gameplan as a result of he will get nice journey 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):

Each hurlers navigated final season with a sweeper and slider in tow, and each added a cutter this 12 months. However 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. However 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 major breaker this 12 months. If it didn’t, that might trigger main issues for the pitch’s slot in his repertoire; Wells is doing simply wonderful with out goldilocks-zone horizontal motion on his cut-fastball.

On the identical time, whereas nonetheless in between his four-seamer and sweeper’s horizontal motion, Keller’s cutter really leans meaningfully nearer to 1 aspect (the four-seamer) than the slider that he scrapped for it. However the cutter is nearer to equidistant between the sinker and sweeper than the slider was, which is extra vital for him on condition that the sinker and sweeper comprise the perfect pair for tunneling; each their spin axes and noticed actions are near the perfect 180 levels aside:

Keller’s sweeper has really price him runs this 12 months, however its swinging-strike charge has shot up practically three p.c. In the meantime, each his sinker and four-seamer have improved dramatically by CSW% and run worth per 100 tosses. To not point out that the cutter itself is performing very well, with higher CSW and barrel charges than the slider he scrapped for it.

Another excuse for Keller’s enchancment this season has been elevated horizontal motion throughout the board; he’s added practically 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 towards 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, but it surely 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. However maybe, amidst a little bit of a dry spell, now’s 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. On the identical time, whereas some regression is definitely so as, the ground at this level remains to be a serviceable rotation choice, one thing that the Orioles — house owners of the Twenty sixth-worst starter WAR this season — are in dire want of.

If Wells continues to seek out success, it is going to go a good 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 unbiased of the whirly would possibly even stave off its extinction sooner or later.

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