Yang Hyun-jong is a 25 year old (turns 26 next March) left-handed pitcher for the KIA Tigers of the KBO. Strangely, Yang doesn't have a Naver scouting report despite having quite a bit of KBO experience and is one of the ERA leaders in the KBO this year (he was the ERA leader when he got hurt and remained so until his last outing). Because of this, I thought he was a good player to write a scouting report on.
Yang's most recent outing was coming off injury (from what I understand, a pretty serious rib injury on his left side, costing him nearly a month and a half) and that is what i watched. It was not a good start, as even though he struck out 4 and walked 2, he gave up 4 runs, all earned, all in the first (not to mention nearly imploding in the 3rd inning, amazingly giving up no runs). He jammed 95 pitches into 3 and 2/3rds innings.
He looks pretty small on the mound, but is listed at 6 feet tall. He offers no projection thanks to age, and the fact that he has filled out already. From what I saw, Yang has four distinct pitches with three of them having frequent usage.
Yang's fastball was 87-92 MPH. 88-89 was where he usually sat at. He could sink it, and also got it glove side quite a bit (it was probably a glove side pitch on average), even against righties. He got away with this (his fastball inside being hittable was not his problem in the outing) because the velocity is enough that many KBO hitters couldn't square it up unless they were expecting it. It is not something I would recommend him trying if he ever pitches at higher levels, but Yang used enough off-speed pitches that they couldn't sit on his fastball. He would pitch so aggressively inside that he hit a couple of RHB (he also hit a RHB with a breaking pitch, as his control was really poor throughout the game). Yang could also throw it high like a 4-seam to get whiffs, though this appeared to be less common. He hit 92 MPH in the 32nd pitch of the first inning, and then 91 on the next pitch. Then arm strength seems to be there despite the injury.
His feature off-speed pitch appeared to be a 78-80 MPH change. He was really struggling to get it down and it broke glove side, unusual for a changeup. It had somewhat significant movement when he did get it down.
The second off-speed pitch he threw as 79-81 MPH, down to 76-77 MPH, slider. The break on it was often inconsistent, as at times it would tail away from lefties, but not really sweep or slide. When it did break like a slider it had good drop and often broke just straight down. He would throw it to RHB as well as LHB. It was his best whiff pitch in the game, while his fastball was the best weak contact pitch he showed. This was a much better pitch than the changeup he was throwing, even though he threw the former more.
Yang also broke out a 107 curveball in the 3rd inning to a LHB. It had decent tilt, with a little two way break. He threw it for a strike, but it was probably more up than he wanted. He later tried to throw it to a RHB and it slipped out of his hand, staying very high and nearly becoming a wild pitch.
He has walked over 10 percent of batters this year, so it isn't like he has good control, but it is doubtful he has had such poor control this year. Half of his season's HBP came in one inning of the outing. With the latest outing included, Yang has a 10.95 ERA RAA and 22.94 ERA RAR. However, a lot of this success appears to be randomness or luck, as he has given up a .273 BABIP versus the league average .322. This is why his defensive independent metrics are not as good, with a .52 FIP RAA and 12.5 FIP RAR. Still, this is an improvement considering that he had been worth about 52 runs below average before 2013 according to ERA and 31 runs below average according to FIP.
While it is unclear why he went from a pretty poor pitcher in the KBO to at least an above average starter, but Yang is was considered one of the best pitchers in the country before he was drafted 9th overall (which is actually the second round) in 2007. He has the stuff to be successful in the KBO, or at least the fastball, as there are successful left-handers in the Majors with worse fastballs. Evidently, Yang threw up to 93 MPH in high school. Certainly he would be more interesting if he threw that hard, but he can have success with his fastball velocity in the KBO. How much he actually improves depends on whether or not he controls his breaking pitches.