I've attached a graph of the age of Fujitsu cup winners over the tournament's history. I just used "win year - birth year" so there may be some off-by-1 errors due to birthdays. I also fitted a cubic polynomial to the data, to get a rough idea of general trend.
There are two things that stand out:
(1) An overall decline in age, especially during 2002-2007
(2) A slight uptick over the last few years, possibly providing support for JF's theory that the wave of youth has peaked.

I chose Fujitsu Cup because it is the longest running international tournament. It would be quite interesting to do some graphs for other titles, like maybe Honinbo (going much further back). One tournament isn't really enough data to provide a strong conclusion.

One other small note: the older winners are not all Japanese. Cho Hun-hyeon won twice in 2000 and 2001, when he was 47 and 48. The only older winner was Otake Hideo, who was 50 when he won.

It just now caught my eye, but John noted that Japan was the only country to have a woman in the top ten, but he used the tournament winnings for the Japanese list. Without getting into an argument about the relative merits of various ratings, Japan would not have had a woman in the top ten if the list were computed by the same methods as the Chinese and Korean ratings.

_________________
Occupy Babel!

I did the relevant numbers for the August 2005 Hankuk Kiwon Pro Ratings.

You only have one teen in the top ten, but four twenty year olds, and four more teens in the top 20.

Since John has previously referred to flash in the pan players, I also took the time to see how many of the players from the August 2005 ratings were still in the top 20. If I haven't made a mistake, fourteen are still in the top twenty--which seems pretty consistent after five years.

Using Valerio's list:
Yu Ch'ang-hyeok dropped from 8th to 36th
Cho Hun-hyeon dropped from 9th to 28th.
Kim Seong-ryong was 12th, and does not appear now.
Kim Chu-ho was 14th and dropped to 38th.
Ok Teuk-chin was 16th, and does not appear now.
Yi Heui-seong dropped from 18th to 32nd.

_________________
Occupy Babel!

We can now add Chinese money earnings to the mix for 2010.

At the top Kong Jie won 3.8 million yuan or roughly US$ 575,000. He was well ahead of Gu Li on 2.2m yuan ($336,000). In 10th place was Gu Lingyi at 450,000 yuan ($68,000).

I made a comment elsewhere that Chinese go looked to me to be in a long-term healthy state. These figures bear that out, I think.

Allowing (by licking a finger and sticking it up in the wind) for the lower standard of living in China, Kong's total will compare very well with Cho U's £1.1m in Japan. At any rate, I think we may safely assume that Kong has discovered many new friends he never knew he had.

Gu Lingyi's 10th place compares with O Meien's $170,000 equivalent in Japan.

In Japan, at least, the gap between 1st and 10th place varies enormously from year to year - for the past few years it has vacillated in the range of about 3:1 ~ 8:1.

I did the same thing for Chinese ratings from 2005. They only had 1 teenager then (Peng Quan).

I counted 9 players who left the top twenty between 2005 and 2010--a higher rate of turnover than in Korea. In many ways, that fits with the trend that China has caught up to Korea in recent years--they were still adding new players who were stronger than the ones they replaced in 2005.

For reference, the 9 were Wang Lei Sr, Yu Bin, Luo Xihe, Ma Xiaochun, Liu Shizhen, Ding Wei, Huang Yizhong, Wang Yuhui and Shao Weigang.

_________________
Occupy Babel!