Born on March 1, 1988, in Gwangju, South Korea, one of the country's top gastronomic destinations, Hyeon-Jong Yang honed his baseball skills as a youth. Yang became a standout baseball star as a teenager, pitching for Dongsung High School in the 29th and 30th President's Cup National High School Baseball Championships in 2005 and 2006, respectively, and in the 36th Phoenix Flag National High School Baseball Championship in 2006. In all three competitions, the young left-hander dominated, helping lead his high school team to the finals in all three competitions. Based on his performance in those tournaments, Yang was named a member of the South Korean Junior National Team in the 2006 World Junior Championship. He posted a 1.04 ERA in 17.1 innings over the course of the event. As a result, Yang was considered a hot commodity and one of the top high school left-handed pitchers in South Korea, along with Kwang-Hyun Kim. Yang was selected by his hometown KIA Tigers with the ninth overall pick in the 2007 KBO Draft.
The young southpaw made his debut in April 2007, and like any other young player, he had some growing pains. Yang's performance—especially his control—was up and down early in the year, and he was therefore demoted from the Tigers at the end of May. He rejoined the team later in the year and was mostly used out of the bullpen, where he was much more effective. All in all, Yang ended his rookie season with a 4.17 ERA in 49.2 innings, an impressive 48 strikeouts, but a disconcerting 31 walks. He actually took a few steps back in 2008, posting a 5.83 ERA in 75.2 innings, with 56 strikeouts and 48 walks. Much like the year before, he was given every opportunity to thrive as a starter before being relegated to the bullpen midseason.
Yang finally began achieving his potential in 2009. That year, he posted a 3.15 ERA in 148.2, with 139 strikeouts and 58 walks. He was among the league in numerous categories, including wins, ERA, strikeouts, and innings pitched. By far, the best game of his career until that point came on August 11, when he threw 7.1 shutout innings against the Lotte Giants, striking out ten and walking none. The team and the pitcher drew momentum from each other, and the Tigers ended the season with the best KBO record and a Korean Series victory over the SK Wyverns. Yang was rewarded after the season, being tabbed as the starter for the 2009 KBO-NPB Club Championship game, an exhibition contest played between the winners of the KBO's Japan Series and the KBO's Korean Series. In the game, Yang allowed a run on three hits over five-plus innings, striking out six Yomiuri Giants.
The southpaw failed to build on his breakout season in 2010. Though he won four more games than he did in the previous year with a 16-8 record, he regressed in most other areas. His ERA rose from 3.15 to 4.25, his strikeout rate dropped, and his walk rate rose. The next few years would prove similar, as injuries and inconsistency would limit his time on the mound and how effective he was when he was on it.
In 2013, the bespectacled lefty had something of a renaissance season. Though he only made 19 total appearances (17 starts) thanks to a somewhat serious rib injury that cost him almost two months, Yang posted respectable numbers in numerous pitching categories, including ERA, strikeout rate, and walk rate, for the first time in many years. In 2014, the 26-year-old Yang had a second good season. For the first time since 2010, he eclipsed the 100-strikeout mark, striking out 157 batters in 165 innings. Yang's trimmed-down walk rate and stinginess allowing home runs resulted in the southpaw posting a 3.49 FIP, one of the best marks of his career. While his 4.25 ERA is not impressive on the surface, only six pitchers posted an ERA below 4.00.
After the season ended, KIA officials informed the public that Yang had been interested in playing for an MLB team for some time, and that they were weighing the possibility of posting him. "Yang has expressed strong desire to go overseas," a KIA Tigers official said. "We're reviewing the possibility while considering a wide range of factors.
In November 2014, the KIA Tigers went ahead and posted Yang. There was initially some confusion as to what MLB team posted the winning bid, as some reports claimed the Minnesota Twins did while others claimed that the Texas Rangers beat them, but in the end, it wouldn’t matter much as the Tigers rejected the winning bid, feeling that it was too low an offer. "Yang maintained that he wanted to go play in the majors, but he also seemed to understand our position," said an official with the Tigers. "He accepted the team's final decision." As such, Yang was not released from his contract and suited up for the Tigers for the 2015 season.
The failed posting ultimately proved a boon for the 27-year-old southpaw. He would have a career renaissance, posting some of the best numbers of his career despite a KBO environment that was heavily skewed towards hitters. In 2015, he had, by far, the best season of his career. In 184.1 innings, he recorded a 2.44 ERA- not only a career best, but was the lowest in the league among qualified pitchers- allowing 150 hits, striking out 157 and walking 78. His numbers in 2015 were similar. Eclipsing the 200-inning mark for the first time in his career, he posted a 3.68 ERA, allowing 191 hits, walking 77, and striking out 146.
After signing the most lucrative one-year contract in KBO history worth ₩2.25 billion won- roughly $1.9 million- Yang began the 2017 season on a poor note, as he did not perform well in the 2017 World Baseball Classic. Once the KBO season began, the left-hander turned things around in a major way, going on to win the KBO MVP Award. For the year, he went 20-6, with a 3.44 ERA in 193.1, walking 45 and striking out 158. The left-hander went 13-3 with a 3.86 ERA in the first half of the season and 7-3 with a 2.90 ERA in the second half. His momentum carried into the KBO playoffs, where the KIA Tigers took on the Doosan Bears in the Korean Series. In Game Two of the series, he held the Bears to just four hits and struck out 11. He made another appearance in Game Five notching the save in the 7-6 ballgame that had once been a 7-0 Tigers lead. It was only fitting that he was on the mound when the Tigers won, as Yang told reporters, "I've dreamed about finishing off a championship game for a long time, and everything became a reality." He was voted Korean Series MVP by a large margin, and a few days later, was voted KBO MVP, the first time in the 35-year history of the league that a player earned both honors.
A free agent, MLB clubs have put in status checks regarding his availability. Given his previous desire to play in the United States and his unrestricted free agent status, perhaps 2018 will be the year Yang will be able to do so.
Throwing from a high ¾ arm slot, the left-handed Yang has a fastball that sits in the high-80s to low-90s. The velocity of his fastball was erroneously reported as being much higher by Daily News reporter Mark Feinsand, but as I pointed out when Yang was first posted by the KIA Tigers, his reports were grossly exaggerated. For a southpaw, such velocity is roughly average, and is enough to get by at the MLB level. He complements his fastball with a slider, curveball, and changeup. His slider is a low-80s pitch with good vertical tilt. His curveball sits in the low-70s and features 12-6 drop. His changeup features roughly 10 MPH in differential from his fastball but lacks fade. Overall, his slider is his best secondary pitch when it is working, generally reserves it for his strikeouts, while his changeup is his least effective pitch.
Despite what Yang throws and how hard he throws it, a pitcher will have difficulty succeeding if he doesn't know where the ball is going, and Hyeon-Jong Yang historically has had such issues. For his career, the left-hander owns an ugly 4.1 BB/9 rate. He has improved in the last few years, but earlier in his career, the southpaw was regularly posting walk rates north of 5 batters per nine innings. Part of the control problems he has had during his career has been inability to command his fastball, as it can get good glove-side run and sink, and part of it has been inconsistent mechanics in his delivery. The landing point in his long stride is inconsistent, prompting his release point to bounce around.