A big part of chess is that you get confronted with yourself, and you need to learn to lose gracefully if you'r going to play. In a way, you not only need to work on your game, you need to work on yourself too.
Why is Online play SO UNFAIR?!

For a few minutes, I'm on a winning streak and JUST got to 800 points and am intrigued to get to 850! But then, SO SO SUDDENLY, someone SO GOOD comes along and COMPLETELY CRUSHES ME. CHESS.COM CAN SEE I LOST THAT ONE, so did they give me an easier opponent? NO, THEY DID NOT. I WON 3, BUT LOST ABOUT 10 IN A ROW!!!!! HOW IS THAT FAIR?!?!?!
You cannot win every time.
You don't play against everybody on the whole server, only a limited subset. Therefore, your rating is far off from other players that are not your immediate opponents.

Life is unfair.😢
That's why I say "Chess is as fair as it gets." Very little, if anything, in life is as fair as chess. If a person whines that chess is unfair, I don't want to know what he thinks about other aspects of life.

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Online it was just brute force "it's ALWAYS a check or capture." I assume that's how some really bad players have super high puzzle ratings... when the moves are always extremely forcing all you have to do is guess which check or capture is right.
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This is not true. There are a lot of more complex puzzles in the system.
same as me lol
760 rapid and 2300 puzzle XD

This is very normal. Ratings don't equal strength. You can be an 800, and get 800-870 rated opponents, but your opponents can be underrated or overrated. If this upsets you, you can always set your opponents' minimum and maximum ratings. To do this, go to the play section choose the time control you want to play, and click "Custom". There you will see "Rating Range", edit it. You'll get opponents in the rating range you set.
thanks
When I was new to puzzle rush I had the same problem... there were times I'd spend a few minutes calculating on a 1200 puzzle, because the full solution was actually really difficult... but of course if you play the random scary-looking check you immediately get it "correct" without needing to input any more moves and you move on to the next one.