View more analysis of Rucinski’s season in the KBO here and check out his player page on the KBO Wizard. And enjoy this clip of his cutter in action.

Rucinski has been consistently good for the Dinos over the last two seasons, posting a combined 3.10 ERA over 301.2 KBO innings, the ninth-best mark over the 2019-2020 seasons. In 2020, he’s sporting an ERA of 3.22 and FIP of 3.94, which is good but resides just outside of the top tier of starting pitchers in the KBO.

Rucinski wasn’t quite as sharp as he normally is, but he still pitched well against SK. For the 2020 season, Rucinski has been about average with a 64% strike% and an F-Strike% of 63%. Against SK, both those numbers were down, with his strike% just barely at 60% and an F-Strike% of just 54%. Interestingly, both those numbers dipped despite his whiff% of 24% against SK, a few percentage points higher than his 22% whiff rate on the season.

That’s likely due to his swing% falling from 48% on the season to just 41% against SK. These are lots of small differences but seem to indicate that Rucinski was struggling to locate his pitches more than usual, something I noticed while watching the game. He was throwing in the zone a lot less against right-handed hitters; against SK’s right-handed hitters, Rucinski threw 33% of his pitches in the “chase” zone on the edge of the plate, compared to just a 28% mark over his other starts this season, which came with a small reduction of pitches over the heart of the plate from 19.1% on the season to 17.8% against SK. Again, we’re still talking about really small samples in regards to this start, but this indicates that he was throwing more pitches that were not definite called strikes and that he wasn’t getting those calls. While his curveball and slider were above their season average on called strike%, his sinker has below average, and he didn’t get anything out of his tertiary pitches (his 4-seam and changeup).

Even though the umps might not have been giving Rucinski many favorable calls, he did a good job of handling things himself with the types of batted balls that he allowed. Over 17 batted balls, Rucinski allowed a hard-hit% of just 24% and a fly ball% of 29%. A majority of the balls that where hit were hit softly and either on the ground or for a pop-up. As a sinker heavy pitcher, that’s exactly what you want to see from Rucinski. He’s been really good at that all season, with his XBH% of 4.6% the third-lowest in the KBO with a minimum of 350 pitches tracked be me in the KBO Wizard.

In addition, despite his K/9 of 7.75, which is good, not great in the KBO, and a K/9 of 6.42 against SK, Rucinski sports one of the best swing and miss pitches in the KBO with his slider. Among pitches thrown 150+ times this season, his whiff% of 37% on his slider is the second-highest mark on the season. Rucinski usually throws it down and away from RHH and in the zone to LHH. From what I observed and comparing his location plots, that was the biggest difference in how “sharp” Rucinski appeared.

He didn’t throw his slider down and away nearly as often and tended to miss up against lefties, with four sliders missing up, accounting for 25% of the 16 sliders that have missed up in the zone, out of 190 total sliders. That was a consistent theme for Rucinski against SK; the two runs he gave up came off of a walk then HR when he hung a curveball in the middle of the plate to an LHH.

Overall, it was a fine start for Rucinski, throwing seven innings, allowing just four baserunners and two runs. He had a few issues with throwing strikes and his control, but compensated for them with his ability to induce weak contact and easily fielded outs by his defense.

*Stats from the KBO Wizard, myKBO.com, and FanGraphs.com*

That’s why I created the KBO Wizard, a tool to host advanced stats that I’ve tracked from watching KBO games. The newest feature? Pitch type breakdowns that allow you to view pitcher’s success and stats on individual pitches. Pair that with the eye test and I feel confident that these are some of the best pitches in the KBO among pitches that have been thrown 100+ times (with one exception). If you disagree with me, check out the KBO Wizard and let me know why on Twitter @benhowell71. But these are my picks for the best pitches in the KBO:

Aaron Brooks’ Changeup

There’s no other pitch in the KBO that I enjoy watching more than a good changeup from Aaron Brooks. Just look at the way that pitch drops off as it approaches the plate. At an average of 85 mph, how do you hit this squarely? I could watch changeups from Aaron Brooks on a loop all day.

If you have the answer to that question, the KBO teams that have to face Brooks would like to know. He throws his changeup almost exclusively against LHH, using it a total of 21% of the time and it always breaks down and away from LHH. It produces a 23% Whiff%, making it Brooks’ best swing-and-miss pitch that he uses regularly, despite 23% being a relatively average Whiff%, but that’s not the purpose of Brooks’ changeup.

Among pitches thrown 100+ times in the KBO that I’ve charted, Brooks has a whooping 72% groundout rate on balls in play, far and away the best mark, beating Ben Lively’s sinker by 15%. It has the lowest fly out ratio at 2.8% and tied for the second-lowest XBH rate at just 2.8%. With his changeup’s 57% swing rate (second amongst pitches thrown 100+ times), that’s a lot of easy groundouts. That’s a big reason that Brooks has the highest groundout rate overall and second-lowest XBH rate among pitchers with 300+ pitches overall.

Aaron Brooks’ changeup might be my favorite KBO pitch to watch because of the way it moves and it’s success is hard to argue with. His changeup is a huge reason why Brooks has been so successful this season, posting an ERA of 2.60 and FIP of 2.91, the fourth and second-best marks among qualified pitchers this season. Just watch that GIF at the top again and imagine trying to hit that pitch; I’d bet you couldn’t or it wouldn’t go very far.

Dan Straily’s Slider

By most counts, Dan Straily has been the second-best pitcher in the KBO this year, with the third-best K/9 of 9.10, the second-best WHIP of 1.00, and second-best ERA of 2.04. How has he done it? With his slider, an absolutely nasty pitch.

He’s thrown his slider about 37% of the time this season, averaging 84 mph, and against LHH and RHH, which is a little bit surprising, but it’s extremely effective in two ways. Straily throws his slider down and away from RHH and on the edges of the strike zone against LHH. His slider has induced a whiff rate of 41% this season, second-best in the KBO, but the best swinging strike rate at 26%. But what really sets his slider apart if the 18% called strike rate that he gets; no other pitch that has been thrown 100+ times has an SwStr% above 20% and CS% above 15%. Most pitches are either good for called strikes or swings and misses; Straily gets both with just one pitch, resulting in a Called Strike + Whiff% of 43% on his slider, leading the KBO as the only pitch above 40%.

With the way that his slider breaks away from RHH and towards LHH, Straily’s slider is a really tough pitch for hitters to get the bat on as they prove time and time again. Straily’s slider doesn’t show any sign of slowing down and could be the pitch he rides back to an MLB roster spot.

Koo Chang-Mo’s Splitter

If you’ve been following the KBO at all the last few months, you’ve almost definitely heard the name Koo Chang-mo and for good reason. His 10.24 K/9 mark leads the KBO and he’s tops in both ERA and FIP, with marks of 1.55 and 2.77. A big reason for that, and what lands on this list, is his nasty splitter that hitters are finding impossible to hit. This pitch was the sole exception to my 100+ pitches rule; I’ve only charted Koo throwing his splitter 43 times for a 21% usage rate, but you’ll see why I waived that rule.

Koo’s splitter has produced a whiff rate of 46% in the starts I’ve watched, averaging about 81 mph as he locates it down and away from RHH. That equals a 30.2% swinging-strike rate, blowing by anything else in the KBO that I’ve tracked. That’s led to a ridiculous 79% strike rate on his splitter, second place only to Dan Straily’s slider, despite throwing his splitter out of the zone so much.

Drew Rucinski’s Slider

Drew Rucinski would be an ace for most KBO teams, but he’s the #2 for the NC Dinos behind Koo Chang-mo and his splitter. Rucinski’s ERA of 2.88 is sixth in the KBO and the end of the top tier of pitchers as David Buchanan ranks seventh at 3.70. Rucinski has only been striking out 7.70 batters per 9 this season but has been really successful at limiting hits allowed, with a batting average allowed of just 0.234, seventh-best in the KBO.

That’s where his slider comes in. Averaging around 86 mph and throwing it 21% of the time, Rucinski’s slider is used when he’s needs to get hitters out. His slider has a whiff rate of 43%, tops among pitches thrown 100+ times, good for the second-best swinging strike rate of 23%. His slider doesn’t have the most side-to-side movement the way a pitch like Dan Straily’s does, but is more up and down, messing with hitter’s timing off of his fastball.

It’s been a successful combo. In addition to his stellar whiff rate, Rucinski’s slider has also induced a groundout rate of 41% and an XBH% of 0%. When hitters do manage to make contact, the ball isn’t getting hit very hard or going very far, exactly what the pitcher wants. Rucinski has thrown the slider against both RHH and LHH and the approach has worked and I’m interested to see if he uses the slider more as the season continues.

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.

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.

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.