This Angels starter's new pitch is nowhere to be found and that's a problem

After five-and-a-half underwhelming seasons, Japanese southpaw Yusei Kikuchi reinvented himself last season following a deadline deal that sent him from Toronto to Houston. By making three major tweaks, which included decreasing his fastball usage, increasing his slider at the expense of his curveball, and changing his location, he rose to new heights, posting a 2.70 ERA over 60 innings down the stretch. That performance is what led the Angels to believe in him and reward him handsomely this past offseason.

During spring training, it seemed clear that Kikuchi wasn't done reinventing himself. His new role as the ace of the Angels' staff meant that the veteran needed to continue to evolve, stave off adjustments hitters will make in response to his new approach, and prove that he is able to put together a similar level of performance to what he showed in Houston over a full season.

In order to do so, he got to tinkering, working on a sweeper in the spring as a complement to his slider, which had proven to be his best pitch with a run value of 9 in 2024.

Despite the hype surrounding the sweeper during the spring warm-ups, he's thrown just 11 all year, representing 1.7% of his total pitches. Through his first seven starts, Kikuchi has been far from the ace Angels fans were promised with a 4.21 ERA, 5.04 FIP, and the worst K/9 mark of his career (8.17) since 2019 when he arrived stateside.

Yusei Kikuchi needs to utilize his new pitch to live up to the role the Angels envisioned for him

When Kikuchi unveiled the pitch this spring against the Dodgers, he immediately got sensational results, He fooled the great Shohei Ohtani with it while also using it to strike out a quality big league hitter in Will Smith.

Yet the sweeper has been an afterthought this season despite some electric results in a small sample. Kikuchi's sweeper has generated a 33% whiff rate, a batting average of .000, and an expected batting average of .040, and one strikeout despite only his sinker (three total pitches) being used less frequently.

On the flip side, the rest of his offerings have gotten hit pretty hard. Hitters are batting .348 against his fastball with a .500 slugging percentage. Against his curveball, the batting average allowed is .300 with an eye-watering .700 slugging percentage. His slider has far and away been his best pitch, with a .217 batting average allowed and a .370 slugging percentage, though the expected numbers (xBA of .244, xSLG of .500) are much worse.

The same holds true for his changeup, which has surrendered a batting average of .250 and a slugging percentage of .406, which are stark differences from the xBA of .316 and the xSLG of .578 the pitch has generated.

Kikuchi's biggest issue this season is that he's not generating whiffs at nearly the same rate as he did last year. In 2024, his whiff rate of 29% ranked in the 76th percentile, while this season it has fallen off a cliff to just 21.5%, good for the 23rd percentile. It's no surprise then that his strikeouts have taken a precipitous drop and he's been less effective overall.

Still, his slider has been his best pitch on the season with a run value of 1.8 and he uses often throwing them 36.4% of the time, just a couple percentage points off of his fastball utilization that sits at 39.1%.

Embracing the concept of tunneling, throwing two pitches that appear the same out of the hand but arrive at different velocities and ultimately have a difference in break, by increasing his sweeper usage could not only prove that his new offering his more effective than he might think, but also positively impact the performance of his already strong slider.

Tunneling is the concept that has made the changeup a staple in baseball, but for a breaking ball artist such as Kikuchi, it could make make a ton of sense to capitalize on two pitches that arrive on similiar planes yet feature different break and velocity.

Kikuchi's average slider velocity is 86.7 miles per hour, a good deal off of the 81.2 miles per hour his sweeper comes in at. In terms of induced vertical break, his slider drops a good deal more at 4.7 inches of drop versus 2.3 inches on the sweeper. However, the slower sweeper has a good deal more horizontal movement, posting 11.5 inches of glove-side horizontal induced break versus just 2.2 inches on the slider.

Pairing the two not only gives Kikuchi another weapon that has produced exceptional results in a small sample, but it can also augment his best pitch and make it even more effective.

As hitters have seemingly adjusted to the changes he made to be successful in Houston, this proposed alteration of his repertoire could prove to be the next step in his evolution, which hopefully ends up resulting in the ace-like performance the Angels desperately crave.

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