Hi, I have a question about go players like Cho Chikun who manage to win major tournaments (heh, or ANY tournaments). Cho won the Judan last year at age 49, which seems incredible to me. What is the age when go players seem to stop winning? (I'm thinking of the analogy with golf, say early 40's, though it doesn't seem clear to me why older players should be less capable.) Will Cho Hunhyun ever win again, or even be runner-up (he last won in 2002 - twice - according to gogameworld.com)?
I suppose my being 57 (and a terrible player, but trying to improve) has something to do with my interest ;)
In response to your question
In response to your question about the age of when players start deteriorating, I once read a commentary on a game, that mentioned something along the lines of "...Even though he is 48 years old, the age at which most players start waning..." And of course, needless to mention (although I'm mentioning it :) ) that it varies a lot between players. Factors such as health play a role.
About whether or not someone like Cho Hunhyun can win a tournament again, that is a question impossible to answer. The answer will probably be "Yes", but we have to consider the fighting strength of the Korean youngters. Yet we also have to consider that Cho Hunhyun, despite his old age, is still in Korea's top 10.
There are a few records in Japan about the oldest title holders...
Shimamura Toshihiro, at the age of 65, won the Tengen title.
Fujisawa Hideyuki, at the 67, won the Oza title, in 1991.
Note however, that these are old records. Shimamura won the title in the 70s. Right now, the youngters in Japan are probably no less brutal than those in Korea and China. Therefore, winning an open title at an old age is extremely difficult, though possible, based on my humble opinion.
Another of the old age titles...
Rin Kaiho, in his late forties to early fifties, won 5 straight Tengen titles. He also challenged for the Meijin title in 2001, at the age of 58 (or 59).
In addition to the Oza title
In addition to the Oza title GrandYan mentioned, Fujisawa Shuko (Hideyuki) won the Kisei six times in a row during the 1970's, when he was in his 50's. What is remarkable is that there was plenty of young talent at the time in Japan--the famous Kitani pupils (Kato, Ishida Yoshio, Takemiya, Otake, Kobayashi) were starting to dominate most of the titles already. Not to mention Cho Chikun. I would put those 6 players against the top six under-30 players in China or Korea today any day. In that sense, Shuko's achievement is astonishing.