We had nine players at our last session.*
How do I manage that?
No Equality, Only Fairness
I don't make sure everyone gets screen time. I don't make sure everyone gets equal time. I just make sure everyone gets the time they need to do the things they are doing in game. If you're passive, you'll observe more. If you're active, you'll do more. I don't make sure to bring up the passive players and restrain the active players. I just try to adjudicate play and focus on whoever is appropriate for the in-game situation.
At this point, I don't even go out of my way to make sure I hear out the 9-year old in our group. He's played enough to know to speak up when he wants to do something.
Let them Wander
I get annoyed with people who are doing more of something not-game than game. But a certain amount of attention-wandering is needed.
If someone gets a little bored or antsy and needs to had a sidebar conversation with a player, go for a smoke, go outside and throw hatchets and knives, check their Instagram, it's all good. As long as they don't miss their combat turns and don't neglect the game, we're fine.
Heck, I stop mid-sentence and reply to emails about my Monday schedule. It needs to get done, so I do it and move right back to game.
My players manage encumbrance to the 1/4 pound, they deal with mana recovery, they track HP, cumulative healing penalties, ammunition, potions, rations, light sources, etc. etc. on their own. If they need to roll for that stuff, they do it. I don't even check, unless I hear something that doesn't make sense - and usually it's because I lack a piece of information. They fill me in and we move on.
I track the things they can't - the monsters, the dungeon, etc. - or won't - FP, conditions, and so on.
You can't run a game for nine people and watch them all do everything and double-check it for them. They'll play it straight. At least mine will. I can save my attention for other things.
Nothing really huge there, but that's how I manage nine players. If our other two regulars had made it, for a full gaming crew, it would have been eleven.
I'd just have scaled up the above.
* And 2/3 of them were from two families. A father and two sons, and two brothers and one's son. If only my cousin had shown up to help balance things a little!