>>718109071
SBMM is supposed to be strictly skill based, the more you win, the better the opponents you play against until you settle playing people around your skill level consistently. Think ELO.
EOMM is optimized for just that engagement. When people talk about "forced 50/50s" that's what they're talking about. In order to optimize 'engagement' the game will throw you in mismatched teams to force a win or a less depending on what the algorithm decides is better for keeping you playing.
The wrinkles come into play when it's a team game. Is every team the same skill level? Or are some high ranked players carrying shitter players?
Now I won't pretend to know what goes into matchmaking in any given game because I don't like to play rankslop, but I wouldn't be surprised if games that claim to have SBMM actually have EOMM.