Yes, many people starting on a new server enter as a rank lower than their true rank, myself included. And it could be a problem because as you play other 24 kyus (actual 15 kyus) the server starts to think that all these 15 kyus are actual 24 kyus and the ratings adjust accordingly.
I have been playing on OGS for many years now and have thousands of games under my belt, but my rank is still about 4 stones weaker than what it should be. But maybe I’m just not playing well lately.
Keep in mind it’s difficult to compare ranks across different pools. As you can see at http://senseis.xmp.net/?RankWorldwideComparison even though it is out of date you can see that rank can vary a lot depending on which pool you’re in. Who’s to say which rank is a player’s “true” rank? Ultimately a rank should be not much more than a rough indication that if another player in the same pool has the same rank as you, you should have roughly a 50% chance to win. Deriving any more meaning than that out of a rank number gets a little sketchy.
Yes, you are correct. It’s just that many people on OGS have a deflated rank.
If only there was a way to reliably get an even game from players ten stones stronger than me…
I don’t think I have ever run into sandbaggers in any of my games although I have run into people starting new accounts at 25Kyu who are really SDK’s or dans.
re unintentionally sandbagging not beeing possible: I think it is possible. What if someone hasn’t played for a while but was still studying or was playing on a different server. For example, I play almost all my games on OGS but will occasionally play a game on KGS. I have gone up 2-3 stones in strength since I last played on KGS so when I next play on KGS, will that be unintentional sandbagging?
Or if one takes a break from playing games for a month but reads a couple of books and do 100’s of problems in that time, then when one comes back, one may be significantly stronger than their rank suggests (especially at DDK level)
In both of these cases, the person is still intentionality playing at a rank that they know they are stronger than. But I think this is ok in cases like this. Or at least is much better than creating a new account ever time one moves server for a while.
I don’t think this is a problem tho. I just do think that one can sandbag unintentionally
At ddk any number of things can drastically improve your skill even just in a couple days. Sandbagging to me is playing below your level with the express purpose of securing easy wins. If I’ve gotten better since my last game, I’ll probably challenge a player 1 or 2 stones higher than my rank. This isn’t sandbagging this is how the ranking system is supposed to work.
I totally agree with BHydden on this point.
If an account has (like his does) a steep ramp of rank, then it isn’t a sandbagger account, it’s just someone who’s rank on the system is still settling. The jury remains out on whether that was sandbagging until the point where the rank settles. At that point, the person probably was sandbagging if the account then goes dormant. But if the rank slows down and the person keeps playing, then it was simply the system discovering what their rank is in the first place and/or their initial rapid go learning curve.
I started this account at the weakest rank just to see how the ranking system worked so you could say I was sandbagging for a while or that the ranking promotion system is insanely slow. However you want to see it as. 
Incidentally I played mostly small boards, which did not help much in promotion.
Your graph shows that you shot spectacularly quickly to 10k. So I guess you could say that was your actual rank when you joined - the rest you gained through hard work over some extended time…
I think you are a bit salty
That’s a phrase that doesn’t translate very well. IE “huh?”
Anyhow, what I was doing was trying to refute the claim that the rating system is insanely slow. If you look at his graph, it doesn’t look slow to me.