Mamumamu0413's ratings site has a page that tracks the 100 highest rated Japanese pros by age (age 13, age 14, ..., age 50). Unfortunately: (1) it does not have a direct interface to view the ratings history of individual pros by age and (2) it only goes up to age 50. The ratings list covers the period 1951 to date.
Nothing loath, I scraped the site and dumped the data into Excel. A total of 260 pros popped out on my list from this exercise. Obviously the 100th pro on the list can/will fluctuate a lot and add many names to the list. People who appear on the list inconsistently yield career histories with significant gaps that do not lend themselves to pretty pictures. As a strong proponent of form over substance
, I want people of interest whose data will produce nice graphs. I therefore concentrated on high-rated players. Below are graphs illustrating the ratings history of the 19 Japanese pros who achieved an annual rating of 9.0 or higher sometime during their careers as reported on the site (unlike the monthly ratings on the main ratings page, this listing is based on annual average ratings). They are all well-known names. Collectively they have amassed 580 titles (as reported on the Nihon Kiin website; note that no Kansai Kiin player has yet achieved a 9.0 annual rating).The players are broken up into five groups for readability. Cho Chikun's graph is included in all five groups as a dotted line for reference. Why Cho? As the youngest shodan to reach the age of 50, he quite literally defines the span of the data available on the site.
The Gods of Go: Kitan, Go Seigen, Sakata, Fujisawa Hideyuki (Fujisawa S in the graph). This is the least satisfactory graph for a couple of reasons. All of these players began their careers before 1951 so their entire careers are not represented here. In addition, it seems that Mamumamu0413 only included players in the top 100 list if their ratings distribution (RD) was below .5. As a result, Go Seigen and Kitani in particular have significant gaps in their graphs (and are almost certainly missing their peak years) as they were less active in those years. Nevertheless there is at least one big point of interest IMHO. Note that both Sakata and Fujisawa peaked in terms of their ratings in their mid 40's. This supports the common belief, reported in 1971 Honinbo Tournament, that a champion in their 20's was impossible. This belief was turned on its head by the rapid rise of Rin Kaiho in the 60's and the subsequent dominance of the Kitani dojo students in the 70's and 80's.
Otake vs. Rin Kaiho: These two were (are) the same age and viewed as natural rivals from very early in their careers. As it turned out their personal rivalry was rather overshadowed by the larger pool of competitors produced by the Kitani dojo. Nevertheless I have graphed them together here.
The Golden Age of Kitani Dojo: The usual suspects Kato, Ishida, Takemiya, Kobayashi Koichi, and Cho Chikun. Note the range of experience with Ishida peaking at age 25 and Kato at age 40.
The two remaining graphs are presented in my next post due the limitation of three attachments per post.
The horizontal axis is of course the players' age at the end of the year rated (that is why Cho Chikun appears at age 13 even though he qualified as a pro before he was 12). The vertical axis is the rating produced by mamumamu0413 using the glicko-2 rating system (see