"Halo 4: I Get a Woman!" - Sgt. Mjr. A.J. Johnson, RIP

[Timo]

I'm having difficulty understanding something. Can one in Matchmaking simply not join a lobby that starts a fresh game? Or does joining matchmaking of any kind revolve around joining games already in progress? I thought you could join a regular lobby like the past 5 years and start a game in this game.

Matchmaking searches for any game it can, whether it's in progress or not. You can get thrown into a game in progress, stick with the players after the match and get thrown into another game in progress. No way to avoid it.