Why does a person have provisional rating after 4k games

Here is a profile to a player en.lichess.org/@/Nonpareil/perf/horde with over 4000 horde games, but his rating is provisional.

Why is that? Also a few days ago he didn't have provisional rating (it was normal rating).

Interesting. i notice that he is only provisional in Horde and Correspondence chess. Perhaps he has just played unrated games in those variations and only a handful of rated games? That's my best guess.

His rating is provisional because he plays against too many low rated opponents...

To @TheDudeAbides, no he played many rated games. @TheChessPrince is it written somewhere in the rules? It is actually hard to play high rated players if you are the highest rated player and there are ~ 5 who are at in the range of 400 points from you.

That is because I had long winning streak, and got too high rating. Now I have to loose few games to to get rid of "?" and to come back to ranking table.
Lichess ranking system is not very well configured. Unfortunately :(

Its not about rules, its how the glicko-rating
system works... I dont know where to find the page but it says that if your rating deviation gets higher than 110, you get the question mark

Somewhere in here problably. Sorry posted this to the wrong topic, but was able to find the rating thread here.

en.lichess.org/forum/general-chess-discussion/elo-equivalent-on-other-sites?page=1

Epic thread about the qa above: de.lichess.org/forum/general-chess-discussion/why-am-i-not-in-the-rankings-in-the-bullet

@pemo that was a "fun" read. i'd also like to play some devil's advocate but i don't feel like getting engaged in arguments..

just to not leave without saying anything though..

there seem to be some differences on how lichess and FICS (freechess.org) calculate RD changes, and the threshold for a non-reliable rating on FICS is 80 RD (as opposed to 110 RD on lichess).
why is that?

i also feel that FICS RD increases and decreases in a more.. uh.. accurate (?) reasonable (?) manner, at least as far as inactivity time is factored into rd. i'll use myself as an example..

i have not played a rated chess960 game here in lichess in literally over one year, yet my RD is still not even 70 (!!) and just playing a game against some random 1200 would put me back on the active players list.
on fics, getting inactive for like 6 months does put me as, well, an inactive player (high RD). my standard RD is well over 150 for what isn't even a full year of inactivity since it was below 80.

that's not very fair, obviously. a number of players here were notorious for sitting on their top 10 rating and only playing a random loser every week or something, so that their rating would be counted as active and show up on the leaderboards.
would anyone like to elaborate?