This is a random small question, but for the longest time I have been trying to figure out just how strong I am, or at least an approximate neighborhood, and the inconsistencies in IGS at the lower level don't seem to be helping. Well, recently I got the opportunity to play a 4 dan pro. I figure since pros play very consistently, it may be a good measuring stick. Taking into account that he was playing four people at once, what is a good lower limit on how strong I am given that I lost a nine-stone game by about 30 points? Yes, I should have resigned, but by the time I got a proper read on the score, I figured it would be rude of me to not play it out. --BlueWyvern
--Stefan: Ah... Even though a pro's strength is very consistent, I think there is enough 'noise' here to render the experience unreliable as a strength estimate. She was playing different people at the same time. She was playing on the internet. She may have been slightly tipsy (in which case she was probably not concentrated enough to make it a 2 point loss and you ended up with a 30 points deficit)... Sorry, old boy, but I think the 9 kyu AGA on your homepage is still your most reliable indicator for the time being. :-)
--Bill: Good lower limit? 15 kyu.
Suppose that you are playing a teaching game that you have won by 20 points or more. You see that you can kill another group. Do you do it? Possibly, if you think that it will teach a better lesson than there is in the rest of the game. But probably not. Why demoralize the student?
Pros do not play all out in teaching games. The most instructive mistakes are those that the student makes without being put under pressure. I have a friend who takes 8 stones from his pro teacher and sometimes wins. I should give him 8 stones. ;-)
--AlainWettach The only conclusion you can draw is that you were not strong enough to beat the pro with 9 stones in that game. No shame, I am 3/4 Dan in Europe and I wouldn't bet my life on a nine-stone game with a pro (I don't think the pro would bet his life either ;-)). I agree with what was said and I just want to add that, given the way teaching games are played by the pros and strong players, the difference of points has absolutely no meaning. Once the stronger player knows he will win the game, he plays differently. Here is an amazing anecdote. A few years ago, I had a very strange experience in a seven-stone game against Kano Yoshinori 9 pro. In the middle of the small yose, I counted and found out that I was around 5 points behind. Not enough to resign, so I played further and I noticed that he played some very strange moves. When we finished the game, it appeared that he had won by one point. He congratulated me and told me "You are very strong!!!". I must confess that I had a very disturbing feeling!
If you really want the margin to mean something, I advise you to try a game for money against a Korean pro. I heard that in Korea, they sometimes play for a predefined amount of money per point difference. This is of course a very different game...
Dieter: Other anecdotes exist to show the difference in points has no meaning. Like when a Chinese guy came to a club, somewhere in America. He played the two strongest members in the club and won both by 6,5 points. That made him about 3 dan they guessed, in any case quite strong. The next week a 10 kyu played him and complained with his fellows: "I don't know why you guys think he is so strong: I had a very good game against him to lose only by 6,5 points." The stronger members understood they had indeed badly ... underestimated his strength.