Low Rapid / High Daily elo 🤨

I somewhat fit the bill of what you are talking about: I am 1800 Daily rating right now, but my Rapid isn't even 1300.

Here's the short and sweet of why this is common:

1. A much higher daily rating (compared to Rapid and Blitz) is just easier if you regularly check your games and make sure you don't flag. From personal experience, lots of somewhat lower rated players sign up for tournaments and then time out (either because they aren't serious about it - or they weren't super familiar with how correspondence worked and just let the games run out). This is free Daily rating. This lack of seriousness results in an inflated rating in the Daily game rating pool.
2. Game databases. It is legal in Chess.com Daily games to consult game databases. There are some extremely powerful and extensive resources to help navigate the opening and middlegame. I have a personal theory: if a player is at least 1000 rapid rating and learns how to navigate through a large game database, then that player would have an opening/middlegame advantage in every single game against other Daily players rated <1700.

Age is also a factor.

I'm approaching 70, and while I don't play fast time controls I am sure that if I did my rapid or blitz rating would be hundreds of points lower than my daily rating.

Some people are better at different time controls. For sample, the faster the time control the better opening traps work. The longer time control the more you need to be able play a more complete game, opening, middle, and end game.

It is, before I timeouted around 40 games on another site, I was 1700-1850 in Daily chess over there. Even now after so many timeouts, my rating is sitting at low 1500s.

On Rapid chess and faster? I struggle to reach 900 elo in those here, which makes for an 800 point difference.

Reporting them is incredibly stupid. If someone is better at slower, Classical-like time controls, it does not necessarily indicate they are cheating.

Additionally, many players suffer from the opposite problem. They are good at fast time controls but they suck at slower time controls, for example this guy I played on this site, in Daily:

https://www.chess.com/member/maedhros64

I went 1.5/2 in Daily against this guy. Was not even close (for him, lol). He would struggle in Classical time controls, especially in >2h games

I guess this isn't too old to reply to? Although 1500 daily and 500 rapid (your example) would be quite something (unless they only played one rapid game, lost, and gave it up).

But as a ~1500 rapid, I'm expecting to be over ~1700 daily when my rating there settles down. First, daily ratings simply are over 200 points higher on chess.com average (you can look for yourself, it's really closer to 300). Second, I generally play about 2 games at a time, while I have opponents with 20 games, so there is no way they are really paying attention. Third, how long to you spend per move? If I spend fifteen minutes, that's a short amount of time. Fourth, the database is allowed, and you can use other ones too, as long as you don't turn on an engine--which I feel like many people don't bother much.

Bottom line, your daily rating "should be" higher than your rapid, by quite a bit, just given the population mean is over 900 (for daily) vs under 600 (for rapid). And then it's just a matter of how hard you are trying.