The whole entire is worth a read, but I find this passage interesting:
Tazawa was expected to be a top draft pick in Japan, causing one to question how other top-round pitchers his age have done here. The answer, surprisingly enough, is not very well.
Since 1983, 13 pitchers his age were signed as either first-round picks or amateur free agents. Seven failed to win 20 games in their entire careers, three have won 50 or more games, and only one can be considered a star. The lone success story belongs to the man who had a chance to go Tazawa's way in 1999, Koji Uehara. Instead, Uehara joined the Yomiuri Giants and won 112 games.
Now that the 33-year-old Uehara is likely joining Tazawa in the States for next season, it will be interesting to see which of the two ends up with the better major league career.
That is surprising. Tsuyoshi Wada (70-42 in seven seasons) would be one of the other 22 year-old draftees to win 50 games. Off the top of my head, I can't think of who the other might be.
Some time in the next week or so I'll take a look at how other recent high draft picks out of the industrial leagues regardless of age have fared in NPB. I haven't looked at the big picture yet, but anecdotely there seems to be a pattern of needing a year or two to ramp up.