Jung ho Kang: three keys to new-found success

May 10, 2015; Pittsburgh, PA, USA; Pittsburgh Pirates manager Hurdle (left) greets shortstop  Kang (27) after Kang hit a solo home run against the St. Louis Cardinals during the first inning at PNC Park. Mandatory Credit: Charles LeClaire-USA TODAY Sports

Jung Ho Kang belted a solo home run and later drove in the winning run during a 2-for-4 performance in the Pirates 4-3 win over the Cardinals on Sunday. For a fan base that found itself divided by his signing to begin with, the encouraging day was but the latest in a series of encouraging days. This one carried much more weight, coming in a series-clinching win against a hated St. Louis Cardinals rival. Accordingly so, the buzz around Kang is more than palpable at this point among Pirate fans. But how is he doing it? I took a look at many factors when attempting to answer this question, and found a lot to get excited about.

First, let’s set the table with a look at Kang’s traditional batting stats split between April and May.

It is less than two full weeks into May, and Kang already has a comparable amount of plate appearances in May to his April trips to the dish. The difference in results is staggering, including an otherworldly .727 slugging percentage. This more than anything can tell us a bit more about Kang’s improvement, as it shows that he is driving the ball more and turning singles into doubles and potential doubles into home runs.

Now that we have our baseline, let’s see how Kang built that incredible May slashline.

Next: A look at Kang's plate discipline

May 10, 2015; Pittsburgh, PA, USA; Pittsburgh Pirates third baseman Kang (27) throws to first base to retire a St. Louis Cardinals hitter during the sixth inning at PNC Park. Mandatory Credit: Charles LeClaire-USA TODAY Sports

Kang’s plate discipline numbers between April and May show an amazing improvement in his patience and timing. In April, Kang swung at 31.40% of pitches outside of the zone. In May, that percentage has shrunk nearly in half, coming in at 17.10%. Put simply, Kang is adjusting to MLB pitching. This turnaround may be buoyed by Kang seeing more pitches inside the strike zone in May with 57.30% of the pitches he sees being in the zone rather than the 42.240% he saw in April.

Perhaps most tellingly, Kang has lowered his swinging strike (strikes that result from swings and misses) almost 3%, down to 9.1% from 11.90% in April. On the surface, the improvement on swinging strike percentage may seem incremental. Yet when considering that the average in MLB is 9.5%, we can see that Kang has gone from below-average to above-average in a short amount of time.

When we look at Kang’s plate discipline from a high level,we could assume that pitchers are challenging Kang with more pitches in the zone and that Kang is simply taking advantage. So it would seem that this breakout success is merely gearing up to make a regression back to the mean. However, I would point to Kang’s overall Swing % (the amount of times he offers at a pitch). In April, Kang swung at 72.60% of the pitches he saw. In May the bat comes around at 59.60%.

The clear scenario here is that, because Kang is not swinging at pitches out of the zone, pitchers are forced to come back into the zone, and Kang is taking advantage, but he worked to gain that advantage.

Next, let’s look at how Kang is hitting the ball when he makes contact.

Next: A look at Kang's batted ball numbers

Kang’s home run off of Tyler Lyons in the first inning on Sunday was an impressive one. The ball left his bat in a hurry. The home run was the latest indicator that Kang is starting to drive the ball more with each passing at-bat.

In April, Kang was connecting for line drives at a 19% clip, while putting the ball on the infield carpet at a 57.10% rate. In May, his line drive percentage jumped to 23.50% while his groundball rate dipped to 52.90%. Again, incremental differences. The real indicator of Kang’s improvement is how hard he has hit the ball.

Recently Fangraphs.com (where data for this post and many others is pulled from) introduced Hard Hit % into it’s amazing lexicon. Put simply, this measures how hard a batter hit a ball. Of the balls Jung ho Kang put in play in April, only 23.80% of them would be considered “hard.” In May, Kang has hit balls much harder, with a 35.30% rate. Again, Kang is adapting to major league pitching right before our eyes. Also consider that Kang is staring to hit the ball to all fields. After not registering a single hit to the opposite field in April, Kang has a 5.90% opposite field percentage in May.

If Kang can maintain the percentage of hard-hit balls, expect to see him come close to maintaining an excellent slugging percentage and become a reliable run producer whenever he is in the lineup.

Last, we will look at some intangibles, clutch stats, and how they all relate together.

Next: Kang must now put it all together