The Dodgers had a busy offseason. Perhaps their biggest move was signing 23-year-old Japanese pitching phenom, Roki Sasaki. 

However, in his seven games of action so far, Sasaki has struggled, and the reasons are obvious: Sasaki just hasn’t been able to control his pitches. 

Let’s take a look at the amount of strikes Sasaki has thrown in comparison to those that missed the zone.

Sasaki’s first game was close to being a disaster. The rookie threw more balls (31) in his debut against the Cubs than strikes (25). This resulted in five walks, one hit, one earned run and manager Dave Roberts was forced to pull Sasaki in just three innings. 

Sasaki’s second game against Detroit was more efficient, but much worse. Sasaki allowed three hits and two runs in just 1.2 innings of work. The bullpen bailed out Sasaki and the Dodgers escaped with a 7-3 win. 

Sasaki’s best performance was his most recent game. It was also his most efficient, with the strike count being marginally higher than the ball count, especially when compared to his previous games.

The most important pitch for a pitcher to control is their fastball. In his seven Major League outings, Sasaki has really struggled to get his four-seamer in the zone.

The chart below shows the amount of fastballs Sasaki has thrown and the percentage of which have reached the zone.

In the beginning of the season, Sasaki was unable to get his fastball in the zone, limiting his time on the mound in each outing. But, Sasaki seems to be gaining more control of the fastball in each performance, leading to him staying in the game longer and throwing more pitches. 

The fastball is the backbone of the pitching repertoire, especially for Sasaki. It sets up the pitch that put him on the map. 

Sasaki came into the league with one of the most intriguing splitters in pitching history. It’s famous for the unpredictability of its break. Yet, it becomes useless when Sasaki himself can’t control it. 

The chart above shows each splitter Sasaki has thrown and the result. When it’s thrown right, it’s lethal. When it’s not, it ruins his ability to get swings and misses. 

Sasaki’s splitter is most difficult to hit when it’s just below the knees, where he gets the most swings and misses. However, a majority of Sasaki’s splitters have been way off the plate. 

This, coupled with his lower-than-average fastball strike percentage, has been leading to Sasaki giving up a significant amount of walks. 

In fact, Sasaki is tied for sixth most walks given up among pitchers with 20. Even worse is that among the four players tied for sixth, Sasaki has pitched the least amount of innings. 

For pitchers, everything is connected. For a player with a small pitch repertoire like Sasaki — with the four-seamer, splitter and slider being his only pitches — any inefficiencies can ruin an entire outing. 

As is usually the case with pitchers, experience breeds confidence. Fortunately, that confidence is already starting to take shape. Sasaki is only getting more efficient with each game. If he can continue to gain that confidence, the control will come. 

So will the strikeouts.