Looking to create a ranked list for PUBG teams PUBG is a video game played with multiple teams in each game. I am looking to create a rating system so that as teams play each other, they will gain/lose rating based on their placement (1st being the best), how many teams were playing (making it more difficult to survive until the end), and the rating of the teams they were playing against.
For example, if Team A has a rating of 1400, and they get 1st place in a game of 16 teams that all have a combined average rating of 1100, Team A would receive less points than Team B would if Team B had a rating of 1200 and won that same game. The same would go for Team A placing last in a game of teams with a lower combined average rating and thus losing more points than Team B would.
I have been looking at the Elo rating system for ideas, but I am stumped at the moment.
If anyone has any idea of a formula that exists that does this, please let me know! Any suggestions or thoughts are welcome, as I am trying to get this done soon with the scene growing.
 A: Here's a suggestion that uses Elo. View Team 1 as being in an individual match with teams 2 through 16. At the conclusion of the match, we say any team above team 1 "beat" team 1 and any team below team 1 "lost" to team 1. 
Now we can calculate 15 separate Elo rating adjustments and we can take the average adjustment as the change in Elo for team 1.
I think this idea should fit your specifications, although there may be some drawbacks (for example, maybe we want to take something other than the average of all the Elo scores). Try it out and see if it works well for what you want. 
A: Microsoft research has created a ranking system that hadles the ranking in the Halo series of games. It's called Trueskill. There are many extensions of this method that you can find published online, for instance Trueskill 2.
Just a rapid google search will give you many examples with code. For instance Trueskill for DOTA 2.
Just bear in mind that Trueskill is a registered trademark and is protected by a patent; you are free to use it for research, but you cannot develop a commercial product or make money with trueskill. Bottom line, if its research and it's open, it's fine. If you plan on making money with it, look elsewhere :)
A: The Weng-Lin rating systems are perfect for your needs. There are several free and open source implementations in different languages by the name openskill.
