“Talent wins games, but teamwork and intelligence wins championships.”

BAN system in CS-GO

leaving the match at any point before the end (warm-up included)

after a set period of time (not sure how long) with no activity you will be removed

unsure of how many kicks constitutes excessive, but this does not result in a removal, only a cooldown

after team killing for the third time in one match you will be removed

after dealing a set amount of damage in one match you will be removed (believed to be around 500 and includes over-kill damage)
Regarding excessive team-damage and over-kill. You will often see a player team kill with an AWP to the head. This results in about 400 damage and means the next team damage caused by that player normally results in a kick.

Cooldown offence levels and lengths:

Level 1: 30 minutes
Level 2: 2 hours
Level 3: 24 hours
Level 4: 7 days

Cooldown resets:

Every cooldown received increases your current offence level by 1 (your offence level starts from 0)

Offence levels can be decreased by 1 by going 7 days without receiving a cooldown

The 7 days does not begin until your current cooldown has expired
Offence levels can rise above level 4, but 7 days is the maximum cooldown duration

Confusion can arise for extreme abusers when the offence level goes over 4

An example:

A player reaches offence level 4 and gets their first 7 day cooldown on January 1st. The cooldown expires on January 8th. The player can now play in competitive matchmaking again, but their offense level is still 4.

They receive another cooldown on January 9th and receive another 7 day cooldown (because they were still offense level 4), their offense level rises to 5. Their ban expires on January 16th and they don't commit any offences for a week. Their offence level drops back to 4.

Essentially, if you get your second or third 7 day cooldown in a row, it means you need to have two or three clean weeks after it expires before your offence level drops below 4 and therefore will receive cooldown lengths other than 7 days.

ZDROJ[gaming.stackexchange.com]