What's the Glicko RD system about on chess.com?

[IM Jack Rudd]

But from what I understand, the longer you go without playing the more your rating is likely to increase because it reflects an unquantifiable increase in ability. But as stated, I usually worsen if I don't play regularly. I don't see how absence from the board should increase k-factor, shouldn't it limit it?

Think of it this way: if you are playing regularly, the system can be pretty confident that your rating is about right, and so it should be reluctant to change it much = low K factor. If it has no evidence that you're playing regularly, its confidence in its own estimates should wane = higher K factor.

[MJMcCready]

Yes I take your point but as soon as you factor in the unquantifiable, there are bound to be discrepancies. Is an actual timescale used for it I wonder? How much difference does a month off to six months off make?

[Ian Thompson]

Yes I take your point but as soon as you factor in the unquantifiable, there are bound to be discrepancies. Is an actual timescale used for it I wonder? How much difference does a month off to six months off make?

The general description of the Glicko system says the timescale is measured in number of rating periods that have elapsed without activity. That's clear enough with, say, USCF ratings that are updated once a month. How it works with ratings that are updated after every game, like chess.com, is not obvious.

[MJMcCready]

Well I suppose adding a touch of mystique to numbers isn't the most heinous of all chess crimes committed.

[Joey Stewart]

Like many I can go many weeks without playing a single game and letting chess enter my thoughts at any point.

You spend a lot of time talking about chess though, I think it is always there in the subconscious mind no matter how much we think we are free of it. Once you have first moved those pieces there is no escape.

[MJMcCready]

I stopped playing for 12 years and rarely, if ever, thought about chess in that time. But yes at present it is the main hobby.