[isolli]

This reminds of a question I had when I played chess for a couple of years. I was a lot better (as evidenced by my ELO score on chess.com) when playing long games (1 turn per day) than short games (say half an hour total).

At the time, I read that everybody is better at "slow" chess. But does that explanation make sense? If everybody is better, shouldn't my ELO score have stayed the same?

[fpoling]

With more time the scale of change is very personal. For some people going from 15 minutes to 1 hour gives a massive boost, while other do not improve match. And then some people can loose focus or get distracted during longer plays so for them more time may make they play worse.

[orlp]

When "everybody is better", you can still increase your relative rank to other people if you benefit even more.

For example if I were to give $1 to every person on earth, but $100 million to you, everyone would be richer but you would be a lot richer still.

[tbrake]

unfamiliar with chess.com but correspondence chess(day/move) and rapid (game 30+0) should fall under two different rating classifications. Having different ratings between them is to be expected.

And while people tend to make __better moves__ in slower time controls, their rapid/blitz ratings are usually higher than standard ratings.