Can anyone explain this to me ?

Hello everyone,
Today I played a Atomic tournament . When I entered the tournament I have 1802 rating ... I played 14 games there and got 4th place with a performance of 1807 ... Now if my performance is 1807 and I started the tournament with 1802 rating then why in the end of the tournament I have 1796 ratings ... My performance is higher than my starting rating then why I lost 6 rating points .. How is the that possible ? Anyways here is the tournament link
lichess.org/tournament/WRWWfgU7

I have three ideas that might explain it.

The first one would that it works similar to percentages(as your score is a relative value). If you increase and decrease a number by the same percentage you end up with a lower value 100*1.1*0.9=99. As you won a lot in the beginning and lost at the end that might explain a bit of that.

Another point might be that one of your opponents was so much weaker than you that you didn't gain a single point. Because of that the performance score doesn't work properly anymore. Imagine you play 2 people in a tournament(as a 1500 yourself):
A) 1500 1800
B) 1500 2100
You win the first one against the 1500 and lose the second game. So in the end you have an average performance of 1650 in case A and 1800 in case B. Even though you will have nearly the same amount of points your performance will be a lot higher.

Another point is the average doesn't always tell the whole story. In case B you will gain a lot more points winning the first and losing the second, while your performances would stay the same.

Hope that might help. :)

Hello. I had a 1597 rating going into a game with a higher rated player. He offered a draw, which I accepted, and afterward my rating dropped to 1582. Really. Could someone please explain?

Only the band Blondie can explain Atomic. Blondie were...atomic!

Thanks @hadfcdg for helping me ...

And thanks to Vegemite for bringing up Blondie! That song and "Dreaming"...my favorites. :)