https://www.coh2.org/topic/84257/useful-interesting-threads-2-0
If you want the practical answer:
1-The ladder is based in an ELO system. A new account is assigned X number. If you win against someone who is ranked higher you win more points than if you do against someone who is inferior to you.
While your ELO number is hidden, your position on the ladder is based on this number.
2-How do you obtain this number? By playing at least 10 games with a certain faction, a certain mode and with certain people. Each ranking is independent of the others. Each different pair (2v2) or team (3v3+) has a specific ELO number.
3-The interesting part comes from the numerical ladder position vs your rank level. There are 20 ranks, which if you look carefully, you can see that several ranks are missing. This is due to the fact that each of the 20 ranks represent a certain percentile of players which are ACTIVE.
While the ranks 16-20 represents the top200 players, the ranks 15/14 are generally missing cause those represent the top X percentile of the playerbase.
4-Talking about activity. Once you stop playing with a certain partnership and mode for a whole month, your rank becomes hidden. Your ELO remains the same (although it is said to be a certain decay, it's not effective TBH to the point it matters). Once you play 1 game, you have a whole 1 more month till it becomes hidden again.
Why does the ladder look like it is right now?
A) The first 10 games are REALLY important. If you secure around 7/8 wins you should easily be put around top200 even if you haven't face anyone around that rank.
B) Top50 with fewer than say 25 games require a really good WR % depending mostly on type of ladder as well. It's not the same the random ladder than the arranged team ladder.
C) There's a breaking point around +100 games on which you forcefully raise in the ladder by just playing and maintaining around 55% WR.
I like to call this, the PG.Angreifen effect. While the player has a better WR that what i mentioned before, you could see that there are probably better players with better WR on the ladder. But these type of players have gone through such a grind, that they have a higher ELO. This is more notable on random ladders for teamgames.