Minor league numbers cannot tell you everything. Sometimes a quality hitter will fail to put up excellent minor league numbers.
Because proving the non-existence of something--in this case batting talent--is next to impossible, it's hard to write off a minor leaguer simply because his numbers stink.
There are always a few guys who become monsters in the Central or Pacific leagues after looking like nothing on the farm. One reason this happens is that teams trying to transform young players.
A trio of shortstops, Kazuo Matsui, Tatsuhiko Kinjo and Tsuyoshi Nishioka all quickly established themselves at the top level after posting unappetizing minor league numbers while learning to switch hit. On top of that, Matsui had been a pitcher in high school, and like a lot of other young players learned a new position as a pro.
So while we can discount poor farm production, how come teams find it so easy to discount impressive efforts?
Players with big minor league numbers always hit well given regular playing time at the top level, but many clubs haven't figured this out yet.
Sixteen years ago, Takeshi Yamasaki was putting up superior minor league numbers for Chunichi that impressed everyone but the Dragons. A few years after cracking the Dragons lineup as a 27-year-old, Yamasaki said: "If you can hit in the minors, you can hit on the first team."
To the extent one man can prove a point, Yamasaki has done so over his 363-homer career. Of course, it's not just him.
It's Ichiro Suzuki, it's Dave Okubo and it's Katsuhiro Hiratsuka--ignored by Yokohama until injuries forced Hanshin to turn to him and get a serviceable cleanup hitter for next to nothing. It's Toshiaki Imae and Kensuke Tanaka, Akinori Iwamura, Norichika Aoki, Tomotaka Sakaguchi and Lin Wei-chu.
Hidenori Tanoue and Teppei Tsuchiya, Dragons discards despite solid minor league batting records, each claimed a PL Best IX Award a week ago.
Sometimes players make the adjustments to the top level quickly, sometimes it takes a season or two.
This brings us to Yang Zhong-shou. The Hokkaido Nippon Ham Fighters shortstop batted .342 with a .415 on-base percentage in the Eastern League in 2008--numbers suggesting he could hit in the PL, as well.
Only he hasn't. At least, not yet.
Top Fighters executive Toshi Shimada told The Hot Corner earlier this month the team was disappointed with the 22-year-old's slow development.
"He hasn't made the adjustments," Shimada said. "And it's hard to do when you're going up and down a lot."
Yang hasn't succeeded in limited PL playing time and his defense has suffered as well, allowing veteran Tomohiro Nioka to move into the backup shortstop slot behind Makoto Kaneko.
Shimada said Yang had picked up bad habits at the club's minor league facility in Kamagaya, Chiba Prefecture. The ball really carries out to one field and Yang has reportedly tailored his swing accordingly.
"It doesn't help him when he comes up," Shimada said. "He didn't hit well, and then he didn't do well when he returned [to the minors]."
Yang is stuck in the middle, and the club is considering a switch to outfield, where he could concentrate on hitting.
Two qualitatively comparable minor league hitters in recent seasons were Kenta Kurihara and Yuki Yoshimura. Kurihara has since become the Hiroshima Carp cleanup hitter and Yoshimura the Yokohama BayStars starting right fielder. One can bet, despite the current confusion, Yang will be a good first-team hitter sooner or later, although it might not be with the Fighters.
One player who will change teams before paying off is Hanshin's Aarom Balderis. The Western League batting champ and the Tigers' minor league MVP is now out of work.
As the age a player achieves minor league success increases, the chances of a successful transition to the top level decreases. Balderis can play shortstop, but at 27, the odds are long that he'll be a big star.
He is probably a championship-caliber player and could still turn into a monster. And it wouldn't cost a team much to find out.