Life In 19x19

It sure has its mysteries.
The other day I played a Free(!) game against a [-]-ranked(!) opponent, and right after the game finished, my rank changed!
Granted, I was right on the edge between two ranks but still, this was unexpected.

peti29 wrote:It sure has its mysteries.
The other day I played a Free(!) game against a [-]-ranked(!) opponent, and right after the game finished, my rank changed!
Granted, I was right on the edge between two ranks but still, this was unexpected.

I think it's pretty safe to say that this had nothing to do with the game you were playing, and everything to do with minute changes in your ranking based on the shifting ranks of your previous rated opponents, that just happened to line up with a rank barrier.

skydyr wrote:

peti29 wrote:It sure has its mysteries.
The other day I played a Free(!) game against a [-]-ranked(!) opponent, and right after the game finished, my rank changed!
Granted, I was right on the edge between two ranks but still, this was unexpected.

I think it's pretty safe to say that this had nothing to do with the game you were playing, and everything to do with minute changes in your ranking based on the shifting ranks of your previous rated opponents, that just happened to line up with a rank barrier.

Yep. Ranks can (and have) changed in the middle of an ongoing game... multiple times. (This has happened to me, and I've seen it happen to others as well.)

ez4u I was just reading the description if the rating system on the KGS website, and if I understand it correctly, the system would assign you a rating somewhere in the middle.

There is also a certainty value that's computed. For six games, it should always be relatively low, but I'm not sure enough to say if those results would make it especially low.

hyperpape wrote:ez4u I was just reading the description if the rating system on the KGS website, and if I understand it correctly, the system would assign you a rating somewhere in the middle.

There is also a certainty value that's computed. For six games, it should always be relatively low, but I'm not sure enough to say if those results would make it especially low.

Since people were describing the system determining upper bounds based on losses and lower bounds based on win, I was just wondering what would happen if the we had a perverse situation where the lower bounds were above the upper bounds.

I believe that situation only occurs when there are either no wins or no losses since in that circumstance the bare probabilities would guess that you are infinitely strong or infinitely weak. In that case it uses lower bounds and upper bounds to avoid an infinite rating. Once you have one loss and one win, the system looks for the rating that maximizes the probability that you have the observed results.

P.S. You should just read the ratings math page on the KGS website. It's quite readable, and from what I recall, you have the background for it (and I really don't).