What to Expect from Kwang-Hyun Kim in 2021

The Cardinals have approached their potential issues at starting pitcher by hoping that having tons and tons of options that could be good will end up working out. They have Jack Flaherty and Kwang-Hyun Kim. After that, it’s a guy who missed an entire season (Miles Mikolas), a guy who hasn’t been an effective starter in three years (Carlos Martinez), and most of us are hoping to sign a 39-year-old whose upside appears to be league average. The rest are unknowns or unproven.

However, a lot of this is riding on all of us assuming that Kim is a sure thing. Conceptually, having a top 10 or so starter, then an above average one, and then two guys who could be above average with an innings eater at the end is not a bad plan at all. Throw in at least five feasible MLB caliber pitchers behind that group, some of whom are actual prospects, and you have the makings of an above average staff without having to look with rose-colored glasses. But sort of a lot is riding on Kim in this plan.

Here’s a dirty little secret: Kim wasn’t actually that good last year. Or to re-phrase it, if he pitches like he did last year, he will not be good in the future. He had an unsustainably good year last year. He didn’t strike anyone out and he did not have an especially low walk rate either. He had a good GB%, but when you’re dealing with the K/BB numbers he had, you kind of need to be Dakota Hudson in that department and he wasn’t.

Since he had a 1.62 ERA last year, I’ll defend that paragraph. Part of that ERA can be accredited to an 86.6 LOB%. To give you an idea of how high that is, just seven qualified pitchers in 2019 had an 80% LOB or higher. Those seven pitchers averaged 29.9 K%. Kim’s was just over half of that, at 15.6%. Kim’s just not the type of pitcher who will have a genuine talent to keep batters from scoring once they reach base. Not unless he turns into a high K guy. In fact, the closest guy to his K% was Mike Fiers, who had a 78.5 LOB% and has a career 76.2 LOB%. He also has a lot more strikeouts for his career than what he did in 2019, and his 2019 K% was still 16.7%, higher than Kim.

Another thing that helped his ERA was his HR/FB%. It’s definitely too early to say his 9.1 HR/FB% was for real in just eight games played. And you can’t forget about his .217 BABIP against. Players hit .197 against him in 2020. According to Statcast’s xBA, which is expected batting average based on quality of contact, he deserved an opponent’s batting average of .252. Batters had a .247 wOBA against him. His xwOBA was .290. He allowed hard hits at an above average clip - 31.4% - but the MLB average is 34.9% and that is not so large a difference that you’d expect anywhere close to a .217 BABIP.

This is all reflected in the advanced stats though. Sometimes I could just give you the advanced stats and you might wonder why the differential exists. Well the previous two paragraphs explain why. He has a 3.88 FIP, but that’s incorporating possible home run luck. That’s by far his best stats as far as advanced stats go. His xFIP was 4.52, his SIERA was 5.00 and his DRA (deserved run average) was also 5.00. There’s an argument that he may be able to induce weak contact, but to be honest, it’s just not reflected in his stats at all. Any stats that we can use right now at least.

Now, with all of that said, the good news is that he only made 8 appearances. If he did what he did last year over a full season, aside from the fact that he would absolutely not have a 1.62 ERA, I’d be more concerned. 39 innings is virtually nothing. He also accumulated those innings in an extremely unusual way. He had a pretty bad debut as a closer and that was his only appearance as a reliever. When the Cardinals returned from the COVID layoff, he had a really bad appearance as a starter. He was more or less fine after that. There are reasons to believe he won’t have his start in 2020 begin like his 2019 started and there are reasons why you’d expect his 2019 start to negatively impact his performance. Nerves for the first, long layoff for the second.

If you remove those first two appearances, it looks better. Not anywhere near a 1.62 ERA quality pitcher, but better. His K% rises to 17.3% - still lower than you’d like granted. His BB% also falls. None of the stuff I mentioned above really changes - his LOB% is actually higher if you remove his first two appearances, his BABIP is lower, his hard hit% is actually a little bit higher, and his HR/FB% is even lower. His xFIP falls to 4.32, his SIERA falls to 4.73 and his FIP falls to 3.40. I don’t have access to his DRA not being subscribed to Baseball Prospectus, but I imagine that would fall as well.

So where does this leave us? Well, with just 39 innings of major league ball, unfortunately my route is to go to the projections - but with a disclaimer. According to ZiPS, Kim is a projected 2.3 WAR pitcher. Which would inevitably lead to many, many fans being disappointed with him if it happens. People who regularly read VEB probably won’t, but following a 1.62 ERA season with whatever ERA results in a 2.3 WAR season will be perceived as a massive drop in performance. ZiPS sees a rise in K% to 19.7%, nearly league average. Also sees his BB% falling to 6.2%.

ZiPS mostly just sees a repeat of 2020 - after his first two not very good appearances - with a 4.31 FIP in 140 IP. Given he’s 32, I’m not necessarily sure you should plan for more than 140 innings, but just 140 innings means ZiPS does think he’s better than a 2.3 WAR pitcher. Over 170 innings, that’s a 2.8 WAR pitcher. He was projected for 157.3 innings in 2020 originally and it seems a tad unfair to knock him as many innings as ZiPS did. I’d say some age-related innings decline and you got a 2.5 WAR pitcher projection here.

Here’s the fascinating thing though. I was going to present a possible solution to ignore 2020 - because it’s just too few innings and too weird of a season. But oddly enough, ZiPS thinks he’s a better pitcher now than they did before the 2020 season. I imagine some of that is simply having MLB data to work with now. But before the 2020 season, he was a 2.2 WAR pitcher in 157.3 innings. He is, no questions about it, seen as a better pitcher now than before 2020.

That’s definitely curious. Maybe we should still ignore 2020 and call him a 2.2 WAR pitcher. I would have thought he’d have a good projection still, but that would be because he had a good projection based off KBO stats, not an improved stat line from actual MLB data. But like I said, I imagine him simply have a 1.62 ERA over 39 innings - no matter how small the sample and no matter how he got there - ended up weighing quite a bit because MLB data is more valuable to have than KBO data for a projection.

So what to expect from Kim? Despite being in danger of disappointing your average Cardinals fan, I think we can expect an above average pitcher. The Cardinals are gambling with the rotation, but thankfully Kim doesn’t appear to be a huge gamble himself.