Rating calculation

Hi,

I couldn't understand for sure (from FAQs and some player's opinion)

whether rating  after the gane is calculated according to opponent's rating

in the beginning of  the game or at the  end of it (may be quite different).

Somebody knows?

Thanks

The ratings will be calculated from the opponent's most recent and accurate rating at the time of the game ending.

Anybody noticed that the ratings seem far more volatile lately? I seem to gain or lose many more rating points for wins and losses than before.

Used to be I gained 8 points agains someone my own rating, now it's much more:

I lost 19 rating point after losing to a player 150 below, and gained 14 after winning against someone very close to my own rating...

Perhaps the guy who was close to your own rating had a high RD, which would result in larger rating swings as they haven't played many games lately.

Rooperi: as Nytik just said, your rating change does not only depend on your & your opponent's ratings, but on the relative uncertainty attributed to your and his ratings which is given a value known as the Glicko RD.

High uncertainty on your rating means high rating change potential for your rating and high uncertainty on your opponent's rating means lower change potential on your rating.

(Assuming that you play games on this website with a fairly consistent frequency) if ever your rating adjustment seems higher or lower than normal, you can attribute this difference to a high/low uncertainty of your opponent's rating which was taken into account in the formula used to calculate your rating adjustment.

Ok, I get that...but

My rating should be fairly certain, I play a LOT of games here all the time. Surely, if my oipponent has a high RD, it should affect his rating more, and mine less? Or am I missing something?

Alright, I'll give you a scenario to help you understand why the uncertainty on your opponent's rating affects your rating adjustment.

Mr. Kramnik signs up here on chess.com and, like everybody, starts at 1200 rating. Now, you and I both know that his rating will only become "stable" or accurate at a much higher value. But, let's say that for his first game at chess.com, he plays Rooperi, a veteran on the website who has achieved a 2100 rating after hundreds of games.

Unfortunately, Rooperi is eventually crushed and suffers a brutal loss. Mr. Kramnik's rating will shoot up, potentially close to 2000~, because of the high uncertainty that was placed on his rating. Rooperi's rating though had a low uncertainty, and yet he lost to a 1200! How shameful.... should Rooperi's rating change a lot, or only a little?

Hope this helped.

Well, I would think it would only change a little, that's my point. But it's my rating, Which should be pretty stable, that is changing a lot. But no Worries, I was just wondering if there was a change, It's not that important to me.

PS, who's this Kramnik you speak of, tell him to bring it on, I'm not losing to any newbie....