When Nori Aoki decides to swing at an offering, the odds that he'll connect with that pitch are incredibly high. Over the last three seasons, Aoki's contact rate of 91.5% is third highest in all of baseball (out of 233 qualified hitters), bested by only Michael Brantley and Denard Span. For reference, the league average contact rate since 2013 is ~79%. To illustrate how good his contact skills have been, below is a plot showing both the O-Contact% (contact % when a batter swings at a pitch outside of the strike zone) and the Z-Contact% (contact % when a batter swings at a pitch inside of the strike zone) for MLB hitters between 2013 and 2015.
I've marked recent Mariners players in red to provide some perspective and to show just how different Aoki's contact numbers are from what we've been used to. (From left to right we have Zunino, Cruz, Trumbo, Jackson, Smith, Miller, Morrison, Seager, and Cano.) His ability to make contact and put the ball in play has also dramatically suppressed Aoki's strikeout rate. Aoki's 2015 K-rate of 6.4% would've ranked as the second lowest by any hitter in Mariners history (after normalizing to the league average strikeout rate).
|Rank||Season||Player||PA||BB%||K%||AVG||OBP||SLG||wRC+||League avg K%||
Normalized K% (K%/League avg K%)▾
Min 350 PA, league avg K% is for non-pitchers only.
In 2015, Aoki struck out less than 1/3 as often as the average hitter in MLB. The only Mariner to strike out less often (relative to his peers) was Scott Bradley, way back in 1988. Another interesting thing to note is that Aoki is the only player on this table to post an above average offensive performance; he may be somewhat of a slap hitter, but he doesn't swing at too many pitches out of the zone and knows how to draw a walk. This will be important for the M's because Servais will likely slot Aoki in at the top of the Mariners lineup.
Finally, I've seen a lot of people draw parallels between the approaches used by Aoki and Ichiro. I'm sure that some of this has to do with the fact that they're both relatively petite Japanese dudes, but their hitting style is fairly similar. See the ball, hit the ball, run fast, and hopefully get a single. Number 51 is (was) obviously a much better hitter, but Aoki's contact skills have actually been superior to Ichiro's.
|Plate discipline numbers for age 31-33 seasons|
|Ichiro Suzuki||25.8 %||65.3 %||46.5 %||74.4 %||94.0 %||88.9 %||5.1 %|
|Nori Aoki||26.9 %||64.5 %||44.2 %||85.4 %||94.5 %||91.5 %||3.7 %|
Admittedly, this doesn't really mean very much in it of itself. There are great hitters with poor contact skills (Nelson Cruz) and poor hitters with great contact skills (Andrelton Simmons). However, it does serve as another reminder that Aoki's skill set is unique and pretty dissimilar from anything the M's have ever had on their squad. Aoki epitomizes the whole "Just put it in play and see what happens" mantra, which has the potential to provide a nice change of pace from the below-average contact% squads that Jack Z put together the last several years. Hopefully things work out for Nori in Seattle and he's able to contribute 2 or 3 wins—both this season and in 2017.