Jung-ho Kang Is Mashing the Ball for the Pirates

Kang is off to a fast start this season, but can he keep it up?

Jung Ho Kang is on fire.

After breaking his leg on a brutal slide at the end of the 2015 season, the 29-year-old infielder progressed through rehab quickly enough to re-join his Major League club in early May. He’s been one of the most productive hitters in the bigs since his return, including his 2016 season debut in which he clubbed two home runs.

The Pirates bid $5 million to win the rights from the Nexen Heroes to negotiate with Kang in the winter of 2014, and signed him to a four-year, $11 million deal in January of 2015. Historically, very few position players from the KBA have transitioned to the MLB, and his contract reflects that. But he’s a valuable player, as his 3.9 fWAR in 2015 already exceeded the monetary value on his deal (according to FanGraphs).

He had an excellent rookie season, slashing .287/.355/.461 and producing a wOBA of .356 and a wRC+ of 130. He’s gotten regular days off since his return, but so far this year he’s been even more productive with a .262/.315/.600 line, a .379 wOBA, and a wRC+ of 142.

Batted Ball Profile

Before diving into the numbers, it’s important to note that we’re dealing with an extremely small sample size here, as Kang only has 73 plate appearances across 20 games this season.

Having said that, he already has 6 home runs, 4 doubles, and 18 RBI. And everything he’s doing this season is supported by metrics -- he’s hit the ball extremely hard, as evidenced by the chart below.

Soft% Medium% Hard%
2015 18% 48% 34%
2016 21% 31% 48%

His ISO is .338 and he’s striking out slightly less -- down 0.7% from 21.2% of his plate appearances in 2015 to 20.5% this season.

But as exciting as the power outburst is, it's unsustainable. He has a 52% fly-ball rate so far this season (double last year’s rate of 27.6%), and 22 percent of those fly balls have left the yard.

However, with the regression in power should come an increase in BABIP. His .239 BABIP is not only well below the league average BABIP, but below his batting average as well.

He’s also been going to the opposite field with more authority.

Pull% Cent% Oppo%
2015 46.1% 33.1% 20.7%
2016 38.5% 36.5% 25.0%

His recognizable leg kick helps him stay back and balanced through his swing. Take a look at this home run:

Don't Throw Him Fastballs

Kang has destroyed fastballs in his career. Per Daren Willman, his career batting average against four-seamers is the highest of any player versus any pitch since 2008 with a minimum of 150 at-bats per pitch. If you wanted further evidence, here's a heat map of his batting average against four-seamers.

Subsequently, pitchers are trying to adjust -- 55.7 percent of the pitches he saw last season were fastballs. In 2016, that number has dipped to just 42.4%, but he's driving the ball more than last season anyway. As the sample size grows, we'll be able to tell if his growth at the plate is truly sustainable. Regardless, Kang is a fun player to watch, and Pirates fans (and baseball fans in general) should enjoy the ride.