How to not be a poor sport?

you are projecting your insecurities into the chess. this is just a game, your goal should be having fun.
try not to see your loses as a loss, making mistakes is the way of learning. try to see it as a progress, you are actually gaining knowledge and experience.

Treat other players respectfully and how you would want to be spoken to. It's as simple as that! As stated above and my favorite chess quote; "Win or lose you always learn!"

It's how you see being beaten. If you see a defeat as someone insulting you of course you'll be angry. Instead think of every game as a learning experience, if you see every opponent as a teacher giving you their time for free and each defeat as someone giving you the benefit of their time and experience to help you become a better player you'll be less likely to be angry.

This might be in line with what was said here... When I lose a game, I like to analyze it and replay with the computer suggesting to me what were the best moves. I'm still learning all the tools on the site... There are overwhelming reports after a game. I want to improve so I see it as an opportunity to learn a new combination. If I win all the time, I get bored because I learned nothing new.

Oh yeah... And maybe make a habit of just saying good game or nice move might help. I think when you behave kindly, your emotions stay in a reasonable range too. 😊 best wishes

I resign when I know I'm already losing to show my opponent respect.
At my level though, there are a lot of blunders so I may be losing, but then 3 moves later winning. I resign of course if it's not even close, but I've had some great comeback wins that were nice learning experiences. 😊
Obviously you must tell everyone you play gg, but not during the game.
I learn so much in these forums.

If you are a competitive person or have a perfectionist mindset, losing is not fun. Just remember that a chess game does not define who you are as a person and it is just a game. It is supposed to be fun and if it it stops being fun, then take a break and do something else. Also, try not to play angry. It is easy to lose several games in a row and get tilted when you aren't thinking clearly due to being upset. I have made it a point to stop if I lose 3 games in a row.
Oh, the question is how to control your anger response. It depends on my mood actually. Sometimes I explode with anger, other times no. Nobody on line knows because they do not hear my verbal release. After I am done yelling and calling myself a moron and idiot and all that stuff, I am fine.

I occasionally get angry playing live chess.
The reason I get angry at live chess is simple; cos opponents can get lucky, aka. you blunder away a won position, or lose on time etc. I've always been someone who gets triggered when I lose via luck. I used to throw tantrums losing at snakes and ladders when I was four years old, seems I was born that way! But if I lose at activities via skill, I never get angry. It's who I am.
Knowing this I focus on energy on activities where little luck is involved. Daily chess (where I make far fewer blunders) is one of them.
So my advice would be figure out why you're getting angry and try to avoid whatever triggers it.
I occasionally get angry playing live chess.
The reason I get angry at live chess is simple; cos opponents can get lucky, aka. you blunder away a won position, or lose on time etc. I've always been someone who gets triggered when I lose via luck. I used to throw tantrums losing at snakes and ladders when I was four years old, seems I was born that way! But if I lose at activities via skill, I never get angry. It's who I am.
Knowing this I focus on energy on activities where little luck is involved. Daily chess (where I make far fewer blunders) is one of them.
So my advice would be figure out why you're getting angry and try to avoid whatever triggers it.
Same
I resign when I know I'm already losing to show my opponent respect.
lmao i drew this game where i was completely losing because my opponent stalemated

Don't think there's need for some complex etiquette. Just treating others as you would be treated is usually sufficient.
Dealing with the anger of playing chess? Play something that actually properly induces rage such as Street Fighter, and then you will be far less angry playing chess.
Online Chess, no matter on what site its played on is risky, and their are so many options to be negative towards an Opponent, like time wasting, unfair play,and cheap comments during a game ,etc. , I personally cant wait to get back into Club Matches, because the Atmosphere is much better there....