Other people's heads contain different information that yours!
There are smarter people out there but they might not have your insights into the challenges and rewards of hydroponic banana farming.
Two days ago you might not have known how to perform a particular task, and searching the internet was fruitless. You might not be the first person to have to work out how to do that from first principles -- but you can make sure you might be the last!
Come up with an outline: maybe it's a rant like me talking about Excel ( https://blog.scraperwiki.com/2015/07/eusprig/ ) -- ugh, this sucks because A, and then people do B to get around C, and can't even start to do D, E or F because they're stuck in this way of doing things. Use that to structure what you're writing, flesh out those bare bones.
"And I know there are some big Larps in California, but those still only have about 100 people at any one time."
Well, we've got at least two LARPs in the UK which have been well over the thousand mark for a while now: Lorien Trust (https://www.lorientrust.com/) and Empire (which is run by Profound Decisions - http://www.profounddecisions.co.uk/empire). [I'm excluding Curious Pasttimes, since I have no data, but suspect it's also 1000+]. Typically Empire (which I play and have a better idea of numbers) has around 1500 people: around 1300 players and 200 crew.
Empire is interesting from a Megagame perspective because it places the players as the movers and shakers of the world and then gives them the levers of power -- there are senators dealing with the temporal politics of a ten-nation Empire, the synod wrestling for the protection of man's mortal soul, the mages who bargain for power from the alien beings from outside Creation or for those aliens to not deal with the Empire's enemies. And it's on a timescale of four weekends a year, for years, rather than a one-off game. (This isn't even the only large LARP they run -- I believe their mythological era Odyssey game is several hundreds of players)
And as the comments of the article say; Germany has some epic LARPs too -- and pretty sure other places do too.
That said, I'd love to play in one of these tightly plotted megagames...
[full disclosure: I play Empire, have played Odyssey, and played Lorien Trust a long time ago and wasn't a massive fan. If you book for either of the first two games with 570.2375 we'll both get money off.]
Wonder how much anchoring effect there is (sample numbers are given in the original question). I note the sample numbers are generated by javascript -- are they testing the impact of those numbers?
Also, I don't see why N-step arguments are invalid; everyone who went for the Nash Equilibrium is wrong (the average is not 3/2 * 0); you just need to predict how many step-thinkers people are :P
(I guessed 6, which is approx 2/3 of 2/3 of the winning answer... so presumably I'm two steps too deep :P)