There sure seem to have been a lot of players changing leagues, haven't there? That means that things will be mostly new. Ricky Nolasco, now with the Twins, had been in the National League his entire career. Justin Morneau, now with the Rockies, had been in the American League for all but one month of his career. And now, the Kansas City Royals have landed former Brewers outfielder Norichika Aoki for the endlessly-joked-about-because-of-his-name Will Smith. Other than three starts in Kansas City in 2012 during interleague play (during which, in 14 plate appearances, he got two singles, was hit twice, laid down a bunt, hit a double, and was caught stealing) he's a new name to Kansas City.
What's Good About Him? When the Brewers signed Aoki prior to the 2012 season, the consensus view was that the three-time Japanese League batting champion for the Yakult Swallows was, at age 29, over the hill. He was viewed as a fourth outfielder and played accordingly, starting only three games in April and 15 in May. His hitting and a succession of injuries to Brewers outfielders landed him a regular role that he never relinquished.
In 2013, as the team's right fielder, he led the NL in singles (140), was tenth in hits (171), and seventh in total times on base (237). His .286 batting average and .356 on base percentage compared favorably to the major league averages of .266 and .320 for right fielders. He bats left but actually hit better against left-handed pitchers last year (.781 OPS against lefties, .703 against righties), and he did better against left-handed starters (though not relievers) in 2012 as well. The average major league lefty batter lost 96 points of OPS against lefties last year. Among Brewer regulars, his on base percentage trailed only Ryan Braun and Aramis Ramirez and was 19th among the 64 players who qualified for the NL batting title. He was the toughest player to strike out in the majors. And he played strong defense, finishing sixth in the Fielding Bible Award voting for right fielders.
What's Not So Good About Him? There's one major weakness and one minor one in Aoki's game. The major one is power. His isolated power, defined as slugging percentage minus batting average (i.e., the amount of his slugging percentage attributable to extra-base hits) was the third-lowest in the NL. His slugging percentage was tenth lowest, boosted by all those singles. He hit just 20 doubles and 8 homers in 2013 compared to 37 and 10 in 2012. He's obviously more of a singles-and-speed guy than a power guy, but that lack of power is a drawback.
The second, smaller issue is that he's gone from being a pretty good basestealer in 2012 (30 stolen, 8 caught, 79% success rate vs. major league average of 74%) to a pretty bad one in 2013 (20 stolen, 12 caught, 63% success rate vs. major league average of 73%). He turns 32 in January, so he's at an age where his speed is more likely to regress than progress.
So What Should Royals Fans Expect? Royals right fielders, primarily David Lough and Jeff Francoeur, were pretty bad last year, compiling a .258/.304/.392 slash line compared to .286/.356/370 for Aoki. Aoki's on-base skills far outweigh the prior players' superior power. Further, Royals leadoff hitters had a .309 on base percentage, sixth-worst in the majors last year, while the Brewers leadoff hitters, primarily Aoki, were third-best. The main goal of a leadoff hitter is to get on base. The Royals were bad at it and Aoki's good at it. So this trade is an upgrade for the Royals in two ways: They'll get more production from the right field position overall, and specifically, Aoki's superior on-base skills fills a major need in the leadoff position. And they'll get a strong defensive player to boot. That far outweighs the loss of all those really bad Men In Black references to the departed reliever.