Also, I would like to know how the system handles people joining or leaving mid-match. Perhaps a scalable system would be best, instead of a binary check- present at match end yes/no. Basically, for now (in the profile leave count) I am only considered as being in a game if I were in when it ended. But I would like it to be more scalable, for example if I participated for 80% of the game's direction I should get 80% of the score change.
Sure this system would still exclude genius captains who quickly bring a game back from a near-loss and stalemate, but it would acommodate more scenarios than the current binary ones.
Lastly, it would be nice to keep separate ELOs for the different roles, namely captain and crew- the only fixed roles in the game. For example if I'm an engi-captain who flies a galleon, I would like my games as captain to count towards captain-rank.