In an era of pitch counts, we often hear about pitcher efficiency, or how many pitches it is taking for a starting pitcher to get through innings. Patient teams will drive even a good pitcher out of the game sooner because they drive their pitch counts up. This got me thinking about which pitcher(s) in the Korea Baseball Organization were the most efficient, and which ones were the least efficient. To measure this, I used two simple statistics that are easily calculable by looking at the leaderboards at koreabaseball.com, pitches per plate appearance and pitches per out.
We've seen that more pitches per plate appearance can actually be a good thing for pitchers (most likely because it is more strikeouts). In the KBO, it doesn't seem to matter at all (a correlation of about .086) when it comes to ERA. As we would expect, pitches per out performs much better (.49), a better correlation than innings (-.24) or home runs allowed (-.21). Here are the results for each of the 180 pitchers who have appeared in the KBO this year, sorted by pitches per out
Out of pitchers with at least 100 innings pitched, the Dinos' Eric Hacker is the most efficient, with 5.14 pitches per out, meaning it would take 139 pitches to throw a complete game in an average outing for him (or more helpful, he can go about 6 and a third inning on 100 pitches in an average outing). Woo Kyu-Min has been the most efficient Korean native this year (minimum 100 innings) at 5.15 pitches per out. Since all Korean pitchers will be unfairly compared to Ryu Hyun-Jin, Ryu's pitches per out total in 2012 was 5.2, slightly worse than Woo and Hacker. Woo is a 28 year old right-handed pitcher for the LG Twins. What is amazing about Woo and his efficiency this year is that he has worked as the team's closer in the past (57 saves from 2007 to 2009) and he has already set a career high in innings. He has been a bullpen pitcher transitioning to the rotation and not only has he been good, he has been efficient as well.
In 2012, Woo threw 92.2 innings, which was a career high by 18 innings. This year, he has blown by that, throwing 129 innings already. He is not a high strikeout guy, with a 14.9 K%, but he isn't walking many either (4.7 %, though 10 HBP seems high), and is doing a superb job of keeping the ball in the ballpark (.007 %). His 3.42 ERA doesn't seem fluky as those peripherals show (and as far as I can calculate it, his BABIP allowed is about .313, .007 below league average), and it ranks 8th out of qualified pitchers, better than Chris Oxspring and Andy Van Hekken, both pitchers who were given short shots in the Major Leagues.
What makes this more amazing is the fact that Woo is a sidearm pitcher:
In GIF form we see the leg kick and pause he uses before going down in his delivery to gain some deception:
Naver calls these sinkers and says he will throw it anywhere from 77 MPH to 89 MPH. I didn't see a lot of 4-seam fastballs, but Naver says he throws a lot of them and it is usually in the 84-89 MPH range.
His slider (74-80 MPH) is just sort of a strike pitch, it didn't seem to have much movement to me and mainly works because of the change in location and velocity. His changeup (66-81 MPH) seems to be used less, but he will throw it to a right-hander as well and he can get it to move well both horizontally and vertically out of the zone for whiffs. Naver does note that he doesn't have a power breaking ball (he also throws a slow curve according to the scouting report, but I didn't see it) and this would make sense considering the low strikeout rate. However, this isn't extremely unusual for a sidearmer. In fact, Brad Ziegler is a pitcher with a similar release point with similar velocity and he has a similar MLB strikeout rate. Ziegler is an extreme groundball pitchers, one of the best in the Majors, and considering his home run rate, Woo probably is an extreme groundballer as well (there are sidearmers that are not groundball pitchers and instead rely on strikeouts, like Darren O'Day, but it is clear that Woo fits the Ziegler mold better).
In the limited sample I saw of him, it looked like he did a good job of keeping the ball away, regardless of platoon. From an international perspective, it isn't a big deal if Woo doesn't miss a lot of bats. He uses a funky release point that will be hard on right-handed hitters, has decent stuff for the arm angle, can fill up the strike zone, and hopefully keep the ball low and away. MLB teams won't let a pitcher with this release point start games (for good reason), but his efficiency could be very useful out of the bullpen. Sidearmers are often asked to pitch as long men in blowouts by MLB teams, something that destroyed the stats of pitchers like Cody Eppley and Yoshinori Tateyama, and if his efficiency carries over, he could be very useful in that role, along with being a right-handed groundball specialist.