Hello everyone, greetings of the day!

So yesterday, I finally got my premiere rating for CS and it's 11k. I don't know much about the premiere and would like to know how the rating is being calculated. I looked up at the internet and found the rating to be average which is reasonable because I am noob/rookie level so justifying my stats. I checked my stats csstats.gg and my rating was around 0.5. My friend has a rating of around 1.12 and yet he got only a 7.9k rating last week.

Do anyone knows how this is calculated?

PS: Sorry if my post seems irrelevant or stupid, but I am trying to get knowledge about this thing.

thank you!