I don't own 20 champions yet so I can't go in and find out myself, and Google isn't helping at all. Could someone please explain to me what the difference is? Also, why are premades of exactly 4 players disabled in flex?
Solo/duo is only for one/two people and in theory focuses on individual skill.
Flex is for 1, 2, 3, or 5 people, and in theory focuses on teamwork more than individual prowess, so the idea is you can queue up with your friends and have coordinated plays. 4 man premades are disabled because it's often a particularly bad experience for the 5th person, as the 4 premade may be on their own comms and may not communicate at all with the 5th, or if they do communicate it's more "do this, we say so" and it can be more of a bully situation.
Flex is a bit of a fiesta in practice since theres a lot of variance in skill level in any given game, so it can feel a messy as normals, where diamond skill individuals can be in the same match as bronze skill individuals. (Again the theory is that maybe peoples extra teamwork and coordination could allow lower individual skill players outplay uncoordinated higher skill people...but it's messy.)
Flex is mainly for groups. Parties of four are disabled because there are very few players who que solo in flex que, so it would take forever to find a game
4-man premades are disabled because 4-man premades are toxic hellholes (around 50% of the time) and nobody wants to get matched with those scumbags. I gave up playing normals years ago just to get away from 4-man premades.
Flex is the ranked mode that people mess around in. It's basically Normals<draft <flex<<<solo in terms of how much people care about winning.
Solo Queue can have 1 to 2 players queued together.
Flex Queue can have 1 to 5 players queued together.
Four-man premades are disabled because it shortens matchmaking and helps prevent toxic 4-man groups from harassing solo players.
