Concerning competitive skill rank..

First of all I’d like to say I’m really enjoying Halo 4 and am eagerly anticipating the return of a skill based rank. However, I have one question that I’m really trying hard to figure out. Assuming the CSR takes into account wins/loss (like H2 and 3)…how is join in progress going to factor into this? Are players going to be punished for joining a game where their team is already losing? Is quitting going to count as a loss like previous games? Any clarification would be appreciated.