Norichika Aoki: Going Inside the Numbers

After splitting the first two games of a series that many fans, analysts and pundits probably considered to be a battle between two disappointing ballclubs rather than a competitive bout between to postseason hopefuls, the Milwaukee Brewers took the rubber-match of a three-game set with the Chicago Cubs this week by a 4-3 margin in extra-innings on Thursday. The win pushed Milwaukee to 26-31 this season, currently enough for fourth place in the National League Central division.

Brewers southpaw and struggling veteran starter Randy Wolf tossed 6.2 innings of solid ball, conceding just one run of which was not earned on four hits and two walks to just six strikeouts. Corey Hart, George Kottaras and Ryan Braun provided the offense for Ron Roenicke’s bunch, going a combined 4-for-11 with two runs batted in and a run scored. Of course, they weren’t the only players who broke out the lumber against the south-siders.

Former three-time Japanese batting champ and previously questioned offseason pickup Norichika Aoki went 3-for-5 with two home runs — including a walk-off line drive blast over the right-field wall that ended the game for the Brewers in the bottom of the tenth — which was enough to tally three runs scored and two runs batted in. Aoki’s staggeringly unexpected display of raw power on Thursday now gives the 30-year-old a slash line of .303/.357/.487 in 134 plate appearances this season. For an off-the-bench type player who’s slated to make exactly $1,000,000 this season, that’s pretty impressive.

Just what makes Aoki so effective as a hitter?

First and possibly even foremost, he just knows how to make contact with the baseball. This season, Aoki leads all non-injuired Brewers with a contact rate of 88.6% as well as a swining-strike rate of 4.6%, according to Fan Graphs. To put that into some perspective, both of those rates we just mentioned trump Ryan Braun’s contact rate of 80.1% and swinging strike rate of 9.5%. Moreover, compared to the current league average swinging strike rate of 8.8% and contact rate of 80%, it’s easy to see that Aoki’s bat has been well-above average from a pure bat-on-ball standpoint.

The chart below is a subtle attempt to provide an eye-friendly representation of how effective Aoki’s bat has been at making contact on a variety of pitches thus far this season.





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For me, the biggest takeaway from this chart is that when Aoki swings, he rarely misses. The only pitches that one could say he “struggles” to make contact with would be the slider and changeup, however, generally speaking, those two whiff percentages are well above average compared to many hitters this season.

Probably the second-biggest lesson learned from this table has to be Aoki’s swing percent against curveballs and sinkers. Against the curveball up to this juncture of the season, he’s swinging at just 33.3 percent, and against sinkers, he’s pulling the trigger just 29.4 percent of the time. As we all (should) know, these can not only be two of the hardest pitches to hit, but they can also be two of the most difficult to not swing at. To put Aoki’s plate discipline against these pitches into some perspective we must compare and contrast. Joey Votto, arguably MLB’s most disciplined left-handed hitters right now, is swinging at just 33 percent of curveballs and 38 percent of sinkers.

A final way we can look at Aoki’s advanced approach at the plate is to look at his at-bat results. The graph below Aoki’s spray-chart this season.

While Aoki has struggled a bit with infield groundouts, we can conversely see that he has done a tremendous job in spreading the ball to all fields. And despite his falling-away slap-hit style of hitting that many believe should make him largely an opposite-field hitter, he’s been able to pull the ball into the right field corner more often then you’d think. On Thursday, Brewers fans were made aware of that fact with his multiple-home run affair over the right field wall.

In the midst of the palpable stuggles of many Brewers hitters this season, Aoki has come in and has done a magnificent job for manager Ron Roenicke off the bench. He’s been an extremely disciplined hitter at the plate and rarely gets cheated in an at-bat, and that in turn has helped Milwaukee remain relevant in the divisional postseason race.

But, really, should we be surprised?

Alec Dopp covers the Milwaukee Brewers as a featured columnist at Bleacher Report.  Follow him on Twitter @alecdopp and read his blog, Brewers Rumors.

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