What the award is - founded 1950, decided by writers' vote
Founded in 1950, the award goes to the best rookie in each of the Central and Pacific Leagues, decided by a vote of baseball writers. In years without a standout rookie, no award may be given.
Past winners include Shigeo Nagashima (1958) and Hideo Nomo, who won 18 games in 1990 and took the MVP award the same year - a lineage of players who went on to define NPB.
The eligibility rules - why veterans of the farm can still win
The main rules: within five years of first roster registration, and through the previous season no more than 30 career innings (pitchers) or 60 plate appearances (batters) in the top league. Because usage is counted through the prior season, players developed on the farm remain eligible.
Ichiro had lost eligibility by his breakout 1994 season under the usage rule, while players like Roki Sasaki - no first-team appearances in his first year out of high school - emerge in later seasons. The five-year window accommodates diverse development paths.
Using the checker - and its limits
Enter your position type, years since first registration, and career top-league usage through last season; the checker shows a verdict against the main criteria. Inputs are processed on this page only and never transmitted.
This is a simplified test. The official NPB awards rules are authoritative, and eligibility is not the award itself - winners are chosen by writers' vote.
Reference data (tallied from npb.jp official records)
The table below is reference data tallied mechanically from official npb.jp records. Source: Nippon Professional Baseball (NPB) official site.
Data as of 2026-07-26 (npb.jp)
Frequently asked questions
What are the eligibility rules for NPB Rookie of the Year?
Within five years of first roster registration, and through the previous season no more than 30 career innings (pitchers) or 60 plate appearances (batters) in the top league. The official NPB awards rules are authoritative.
Can a player win in his second season or later?
Yes - if within five years of registration and prior top-league usage is under the thresholds. Farm-developed players have won this way.
Who selects the Rookie of the Year?
Baseball writers, by vote - one per league, with no award possible in weak rookie years.