My thought process when I saw this:

Okay, if most people on there are NPR listeners, they'll think: "The average will be around 50, so I'll pick 25." The smarter NPR commenters and all the LW commenters will iterate it one more time, and pick 11. If about 2/3 will do the first, and the other 1/3 the second, the average will be [grabs calculator] about 20, so I'll pick 10. Or better yet 7 or 8, because I'm hardly going to be the first to think this. Oh darn, comments are closed.

ETA (rot13'd because it contains the answer): V infgyl haqrerfgvzngrq gur cbchynevgl bs Cynarg Zbarl naq gurersber bs gur cebcbegvba bs ACE yvfgraref, jvgu gur erfhyg gung V thrffrq n yvggyr ybjre guna gur jvaavat inyhr bs ryrira naq bar unys.

This is a cool game.