Remember
the last time JF was ranting about Mickey Mouse time limits? Well
this got me to thinking. The question that I puzzled over is, "What is the likelihood that a 'hero' (famous fan favorite, outstanding performer and what not), having won a tournament last year, would repeat as the tournament winner this year?" Unusually, I did not fall back on GoGoD and Kombilo.
Instead I turned to excel... Lots of time later

I have more or less simulated all the tournament structures from the reports shown on the
Go News site for Japan, Korea, and China. The results of my analysis were a little surprising to me so I offer them here for your enjoyment.
The Basic Story
I assumed a world in which our Hero stands above the crowd. He/She is able to achieve an average 75% winning rate against three tiers of opponents: T1. Those He/She beats 65% of the time, T2. Those He/She beats 75% of the time, and T3. Those He/She beats 85% of the time. The different tiers show a similar pattern among and between them with T1 beating T2 opponents 65% of the time and T3 opponents 75% of the time, etc. Each tier wins 50% of its games against same-tier opponents. I modeled the different tournament structures in excel with random assignment of equal numbers of opponents from the three tiers to fill out the tournament table (note there was no pyramid of skill - I was too lazy). I set up an excel simulation of each tournament structure (see below), ran each simulation 10,000 times, and recorded the results.
Real World Tournament Structures
There are a surprising range of tournament structures in use. I ignored preliminary tournaments, which would add a great deal of additional complexity. Instead I concentrated on the finals.
Challenge Match Structures
The top Japanese tournaments are all structured as challenge matches where the incumbent defends his/her title against a single opponent. Due to the nature of the question that I asked - can last year's winner repeat - these are simple to model. Challenge matches have become rare in Korea and China. In Korea only the Kuktsu and the Female Myeongin retain this structure. In China only the Mingren and the Tianyuan.
Knock-Out Structures
Tournaments based on single-game elimination are the norm. There are a number of varients in terms of size, whether some players are seeded into later rounds, and whether the final is a mini-match or not. (Note that all numbers below for 'seeded' structures assume that our Hero is seeded as deeply as possible into the tournament.)
Other Structures
There are a few tournaments featuring other structures: double elimination, league structures. I skipped those. The only one in CJK that was impacted was the KBS cup, which has a double elimination format.
The Impact of Structure on "Heroism"
The easiest structure to repeat in is a 7-game challenge match like the Meijin in Japan or the Qiwang in Taiwan. In my mythical world, our hero(ine) retains the title about 91% of the time. At the other end of the spectrum is a pure 64-player knock out like the CITIC Cup in China. Despite standing head and shoulders above the competition, our hero has only a 13% chance of repeating. Basically a shorter KO (reducing the number of 'opportunities' to lose along the way) is better, as is being seeded into a later round and having a multi-game final round. The table below shows the impact of these various features.
CJK Tournaments
Below is the list of current tournaments in Japan, Korea, and China per Go News. I have indicated the probability of a repeat winner in my model world beside each one. I have also indicated a "model" that can be traced back to the earlier table. The real take away for me is the huge differences in the probability column for Japan versus Korea and China. Of course most of us were already aware of the fundamental differences in the tournament structures. However, in my case at least, I was not aware of the impact that it would have. It will definitely be one factor in how the Go 'Scene' in each country appears to us fans.
Take Aways
It is an interesting question to me why we see the differences that we do between tournaments in Japan versus Korea and China. Why does Japan have so many challenge matches or alternatively why do Korea and China have so few? The average tournament in Japan is much older than that in Korea or China: Japan 35 years, Korea 17 years, China 10 years (based on the "Holding" column shown on Go News; and yes I know that I am an idiot for deleting the info from my little table!

). Can it be that modern fans within Korea and China prefer the rough and tumble of big knock outs? This would seem like the easiest explanation for what we see and the willingness of sponsors to support it (and also perhaps a big "Hmmm..." regarding the lack of popularity for Go in Japan?). Many of us outsiders looking in have a hard time keeping track of who is who as new winners keep popping up, but presumably local fans do not suffer from this problem to the same degree.
One last warning
All the numbers in my lists are based on a simple theoretical set of competitors. I am not claiming that Iyama has a 91% probability of winning the Kisei next year or that Wang Xi has a 13% probability of repeating in the CITIC Cup. However, I think the relationships between structures are likely to be reasonably appropriate for assessing the impact of choosing one structure over another. As always YMMV!

_________________
Dave Sigaty"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21