Drew Rucinski Blanks Kiwoom Heroes

Effective slider/curveball combo helps induce 33% Whiff Rate

While MLB Summer Camps are (trying to) ramp up, baseball continues across the ocean in Korea with the KBO. The action is heating up as teams approach 60 games played and tiers start to become more defined. The NC Dinos and Kiwoom Heroes are 1 and 2 in the standings as they headed into game 3 of an important series today.

Courtesy NC Dinos

The NC Dinos beat the Kiwoom Heroes 9–1 to avoid a sweep, maintaining their hold over the #1 seed in the KBO standings. Drew Rucinski led the way for the Dinos, throwing 7 shutout innings and keeping Kiwoom’s powerful bats silenced.

One of the best pitchers in the KBO, Rucinski, a 31-year-old RHP with MLB experience with the Angels, Twins, and Marlins, has allowed just 2 ER in his last 26 IP for NC. His 2.05 ERA is 3rd in the KBO, his FIP of 3.79 is 11th, his WHIP of 1.80 4th, and his LOB% of 86.5% the best in the league. I saw Rucinski’s first start in this scoreless stretch and not much changed from that June 28th outing against Doosan.

In both starts, he threw strikes around 61–64% of the time and excelled at getting ahead in the count, throwing a first-pitch strike 70% of the time against Kiwoom. Rucinski induced a lot of soft contact both times, despite his GO/FO ratio of 0.78; most of those flyouts were popped up. And, of the five hits that Kiwoom had off of him, 3 of them were softly hit infield singles that the batters managed to outrun. His Whiff % also increased, up to 33%, a phenomenal number.

A lot of that weak contact and groundball hits were a product of how he was attacking hitters. He worked up and away to LHH, except for his curveball which he threw down and in. Against RHH, he attacked lower in the zone, throwing his slider and curveball breaking away from RHH and his sinker/fastball at the bottom of the zone.

It’s an effective approach for Rucinski with the 5 different pitches that he throws. His sinker breaks arm side, averaging around 90 mph. He actually upped the sinker usage this time, throwing it 41% of the time against Kiwoom versus just 28% of the time against Doosan. With an uptick in his sinker usage, he didn’t throw as many four-seam fastballs, only throwing it 14% of the time around 90 mph as well. His overall velocity numbers were down just an mph or two and I wonder if he made the conscious decision to go with his sinker, given its greater deception/movement. Whatever it was, it worked as he induced 6 of his swinging strikes on the sinker.

A sinker, slider X 2, and curveball for a swinging strike mix from Rucinski

But Rucinski’s best swing and miss pitch is his slider, inducing 5 whiffs on the 19 times he threw it. Coming in around 86 mph, there isn’t much side-to-side movement, but it has a tight shape and drops right as it approaches the plate. Compared with his curveball, which has a similar shape at 81 mph, but more break overall, it’s a really effective combo. His curveball induced 3 swings and misses, giving him 8 whiffs on 37 total breaking pitches.

Rucinski only threw his changeup 7% of the time and primarily outside to LHH. It came in around 84 mph, giving him another change-of-pace between all of his offspeed pitches. There was nothing notable about it and it’s not worth worrying about from a hitter’s perspective.

Rucinski likes to get ahead in the count early with his sinker/fastball then go after swings and misses with his slider/curveball combo. If he falls behind in the count, he’ll usually turn back towards his sinker, relying on its side-to-side break to help induce weak contact on the ground. His increased whiff rate looks like a result of heavier slider/curveball usage down in the zone, paired with his fastball up, especially against LHH.

Sophomore studying Sport Management and Economics at the University of Texas. Writing about Baseball from an analytical and scouting perspective

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