Won Tae-in Continues to Succeed Despite…Everything Against Him

The young Samsung RHP allows hard contact, base runners, and HRs, but the results are hard to argue with

MLB has returned here in the United States, but in the KBO, baseball continues and the playoff picture is beginning to take shape as teams have crossed the midway point of the season. As such, we’re getting a good sample to start evaluating players for their talent, rather than looking at noisy stats influenced by small samples.

Won Tae-in got the win for Samsung against the Doosan Bears, holding them to three runs over 5.1 innings as the Lions’ bats knocked in six runs of their own. It was another solid start for the 20-year-old who’s in his second season as a pro KBO player. But it doesn’t change the fact that Won Tae-in is one of the most confusing evaluations I’ve done while watching and writing about the KBO.

By conventional measures, he’s been fantastic, posting a 3.54 ERA over 73.2 IP this season, a mark good for eighth-best in the KBO. But he has a FIP of 5.20, making him the luckiest pitcher in the KBO with an ERA-FIP of 1.65. He still sports a K/9 of 5.38 and BB/9 of 3.18, ranking towards the bottom of qualified KBO pitchers in sixth to last and 14th to last, respectively. He’s allowing a whopping 1.10 HR/9, 9th-worst in the KBO, and a batting average of 0.280, 10th-worst.

His saving grace has been his LOB% of 78.5%, tied for third-best in the KBO, with Dan Straily, Raúl Alcántara, and Aaron Brooks, all certified studs. When I evaluated Won Tae-in after his June 14th start against the kt wiz, I wrote that I expected Won to regress as the season continued, but his results have remained steady, even as his FIP has plummeted from 4.25 in June to today’s 5.20.

His problems with allowing contact and baserunners continued against the powerful Doosan lineup on Tuesday. He allowed three total runs, only two earned though, with all three coming in the 1st inning. He hung a fastball over the outer third of the plate and Oh Jae-il sent it flying over the seats, driving in Doosan’s first and only two runs of the evening. From there, results-wise, Won settled in but allowed eight total hits in just 5.1 IP of work, an abysmal WHIP of 1.57.

Of course, Won Tae-in seems to be the one pitcher in the world who does better with runners on-base, which has fueled his success. With runners on-base, Won Tae-in has allowed a 0.219 batting average, versus 0.327 with no one on-base. When there are runners in scoring position? Won Tae-in turns into a pitcher like Justin Verlander if there’s someone on 2nd or 3rd, holding opponents to just a 0.167 batting average (Verlander had a batting average against of 0.171 in 223 IP in 2019 for the Astros and won Cy Young).

That’s ridiculous.

Of course, he has walked the opposing batter 17 times when there is a runner on versus just nine walks issued with no runners, which is not great. BUT even more confusing is that he’s allowed 17 walks with two outs, versus six walks with no outs and three walks with one out. So that favorite Little League coach phrase about two-out walks coming back to bite you does not seem to apply to Won Tae-in.

Maybe Won Tae-in is just a soft-contact master? Yeah, that’s not it if you couldn’t figure that out from his 1.10 HR/9 rate; against Doosan, he allowed a 39% hard-contact rate and according to Sports Info Solutions, Won Tae-in has a 24% hard-hit rate on the season, the highest among pitchers with 150+ At-bats against.

My best guess is that Won Tae-in has been getting lucky. He works in and around the strike zone a lot, throwing 68% of his pitches for strikes against Doosan and a first-pitch strike 71% of the time. Those marks are very similar to his 69% and 67% marks from his June start against kt and his approach does result in a lot of balls in play. From observing these two games, the Samsung defense has been extremely helpful to Won Tae-in as seemingly everything gets hit right towards a fielder. However, with how hard opponents are hitting the ball off of Won, I can’t see that continuing.

Despite his low K numbers and Whiff rate of 14%, below average for the KBO, Won’s “stuff” is pretty good. He throws four different pitches, starting with his 4-Seam fastball that he throws at about 91 mph, using it 44% of the time, against both RHH and LHH. He primarily located it away from hitters or up in the zone, setting up his secondary pitches.

If you’re a left-handed hitter preparing to face Won Tae-in, expect a heavy diet of changeups around 77 mph that dive away from you into the down-and-away corner of the zone. His overall changeup usage was 27%, but against LHH, he threw the same number of fastballs and changeups. Won used his slider and curveball about 16% and 12% of the time. He located his slider, around 80 mph, down-and-away from RHH and inside against LHH, jamming a few Bears into easy groundouts or flyouts. Won’s curveball, thrown around 71 mph was really used to “steal” a strike early in counts, with Won consistently painting the edge of the zone with it for a strike.

Won Tae-in’s swing-and-miss pitches are his changeup and slider, which dive away from LHH and RHH. His changeup seems to be a lefty-only weapon, but he did throw his slider to both. Hitters should be on the lookout for 4-Seam fastballs up in the zone early in the count before Won switches to his offspeed stuff to try and induce easy outs. He will throw the ball in the zone at a high rate and it’s up to the hitter to take advantage of those pitches. He is confident in his ability to throw each pitch for a strike and threw fewer fastballs as the game continued.

Won Tae-in’s success this season has baffled me and I’m still not entirely certain how he’s maintained a 3.54 ERA this season. I still believe that regression is coming for Won, but I guess we’ll have to wait a little longer and see what happens this season.

*Stats from FanGraphs, myKBO.com, the KBO website, and my own tracking of KBO games*

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

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