nabla: And just as a side note on the subject. If the time comes that Fencer does change the rating system, in the past what he had done when a change happened in the rating system was run every single game already played on the site through the rating system to get a new accurate rating..... so if he were to do it again, there is a chance that current games / matches be ran through to get the new rating.

So just a thought to keep in the back of your mind - even though it does not matter to the current rating system, if he were to make the change - there is a chance your current games would be taking into account for the future rating change.

Not that I know if he plans to do it or not - but I have always agreed that it would be nice if different games used different ratings systems... instead of all games be lumped under the Chess rating system which I think he uses.

nabla: It seems to me that the longer a match the more likely that the better player will win, so doesnt that mean that you should get less of an increase in your BKR for those types of matches versus a single game match?

Then again, in a single game match a win for a lesser ranked player should be considered more luck than skill, therefore they too should get less of an increase than if they won a longer match?

Czuch: The latter makes more sense if you want ratings to represent a skill level, doesn't it?

Czuch:  Using the FIBS formula as an example, because it is widely accepted, there are two variables -- match length and the difference between player ratings.  Between players of equal strength, the longer the match, the greater the point adjustment.  Where there is a difference between player ratings, the positive adjustment from a win is greater for the lower-rated player than for the higher-rated player.  Conversely, the higher-rated player suffers a greater negative adjustment if he loses than the lower-rated player would.

Longer matches produce smaller point adjustments if the higher rated player wins, but larger adjustments if the lower-rated player wins.

alanback: Between players of equal strength, the longer the match, the greater the point adjustment.


I would think just the opposite, since the longer the match, the more likely the better player would win, and a likely win should correlate a lesser point adjustment?

Czuch:  I should have said, "between players of equal rating".  In other words, if match length is the only determinant, then longer matches produce larger adjustments, since the skill factor is greater in a longer match.

Your observation about the effect of a likely win is what I meant when I said

"Where there is a difference between player ratings, the positive
adjustment from a win is greater for the lower-rated player than for
the higher-rated player.  Conversely, the higher-rated player suffers a
greater negative adjustment if he loses than the lower-rated player
would."