why did I lose 20+ points in one game close rated?

Some games plus or minus 6 points... I keep losing/gaining 20-30 points in one game???

This rating system seems very inaccurate and random...?

It's because you haven't played a lot of games so far.

This site is a scam.

The Rating system is rigged....making it worthless.

Your RF is still about 90 which means system thinks that accuracy of rating is high. i.e. with 66 % probability you rating is your actual rating +-90 points hence the steps in system are big. RD goes down as you play (and there are no un probable results). It goes up if you dont play for a while

You have also won recently 34 points, beating a player weaker than you...
You don't complain there ?!

@TheChessRat @PuntaArenas The rating system is confusing because Glicko-2 involves a ton of calculations, that makes it seem confusing. There is a paper on the Glicko-2 scale, but once again, it involves a lot of calculations. But one thing I can make sense out of is that after you start with 250 (or was it 350) rating deviation, it will continue to decrease effectively all the time, even if you win all games. But there are instances where RD can increase, for example when you have a huge winning streak after stabilizing near a certain rating for a certain amount of time. But usually, once your RD hits 45 (the minimum bound set by lichess), it rarely goes above 45 (I have seen it hit 45.03 for me, but that itself rarely happens, in spite of my slow increase in rating so far. Right now, my RD is 45.01). And the number of points you get on your game depends on yours AND your opponent's RD. Once I played a game against a 1500 who had just started on lichess (as a 1500). I won and got 4 rating points. Then I played against a 1491 (or somewhere in the range of 1480-1500, while I was a 1500), and got 6 rating points for the win. But @TheChessRat this site is not a scam.

@petri999 I thought that it was a 90% probability that your rating was between current rating - 90 and current rating + 90...
Edit: @petri999 lichess.org/faq#ratings. The lichess FAQ says something quite different about the rating system than what we both described it.

@SavageAntarctican I had it right. One starts with +-350 RD and that is the 66% limit. FAQ at least the translated to finnish one is horrible.

Basically system assumes that your true rating is gaussian/normally distributed around you measured rating. And RD is standard deviation. In normal distribution true value is with 68 % probability within +. standard deviation and 96 probablity within 2*StandardDeviation. See for example here upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Standard_deviation_diagram.svg/525px-Standard_deviation_diagram.svg.png

It dash more complicated actually: Assuming that person with rating X gets rated his measured rating will be with 68% probability true rating +- SD. But difference to using it as limit is so small that there isno point computing the exact value

@petri999 Oh that's what you mean.

Thank you for the explanation.

Feel free to leave lichess. No one's stoppin' ya.