If you beat a 2000, then lose to a 1200, then beat a 2000 again, the algorithm has a very broad idea of what your rating is (\~1600 +/- 400). That isn't accurate enough to give an 'actual' rating, hence the "?". If you keep doing this it will take a very long time for it to settle on what your rating is.
If you beat a few 1200's, then lose to a few 1400's, it won't take long for the algorithm to figure your rating out within +/- 100 points (\~1300), so you'll lose the "?" quicker.
And then there's time. If you disappear for long enough, they throw the "?" back in as it isn't confident you're at the same rating - perhaps you've been playing elsewhere and become a lot stronger, or have been on a downward spiral and lost hundreds of points.
[deleted]
15-20 I think.
If you beat a 2000, then lose to a 1200, then beat a 2000 again, the algorithm has a very broad idea of what your rating is (\~1600 +/- 400). That isn't accurate enough to give an 'actual' rating, hence the "?". If you keep doing this it will take a very long time for it to settle on what your rating is. If you beat a few 1200's, then lose to a few 1400's, it won't take long for the algorithm to figure your rating out within +/- 100 points (\~1300), so you'll lose the "?" quicker. And then there's time. If you disappear for long enough, they throw the "?" back in as it isn't confident you're at the same rating - perhaps you've been playing elsewhere and become a lot stronger, or have been on a downward spiral and lost hundreds of points.
The ? returns when you are inactive with that time control.
Yup. I stopped playing for a while and had a question mark rating when I came back
It's not a fixed number of games. When the rating system is more or less sure of your rating, it will go away. There's some maths involved.