Fireteam size searching?

How does it work? How does it get activated? Or what do I have to do so I don’t have to play against full teams? With the new season here, 343 said that there would be finally a fair matching for solo players, or at it would be less common for solo players like me. I have played about 15 games in three playlists: Slayer, team arena and HCS and I’m no lying when I say that 14 out of those 15 games were against full teams who destroyed me and my teammates. Can someone explain this to me? Maybe I got it wrong and it doesn’t work the way I expected.

There’s a pinned thread above you can use for this question.