Visions of you on a motorcycle drive by, the cigarette ash flies in your eyes and you don’t mind. You smile, and say the world doesn’t fit with you. I don’t believe you, you’re so serene, careening through the universe, your axis on a tilt, you’re guiltless and free, I hope you take a piece of me with you.
The Sorting Hat’s job is to put every kid in an incoming class into the house that’s right for them. And there’s been all sorts of discussion about what criteria it uses, and how much choice plays a factor, etc etc, but I would like to propose a different issue with the Sorting Hat.
Namely: in an incoming class of forty or so kids, how likely is it, do you suppose, that exactly ten kids will be best suited to each of the four houses?
Answer: proooooobably not so much.
Now, there’s two possible ways of dealing with this. Possibility one is that the Hat is programmed to keep the houses just about equal, more or less, give or take a couple of students. Of course, unless the hat can read the whole incoming class and run down enough game theory to optimize sorting without actually sitting on anybody’s head at all just in the course of its opening song–which I am pretty sure canon would deny–the only way to do this is to start shamelessly mis-Sorting somewhere around the middle of the alphabet. What if the entire Weasley line just ended up in Gryffindor because too many sensible students kept enrolling and the hat had to fill a quota?
That possibility is a lot more terrible than hilarious, and I don’t necessarily believe it, which leads us to:
Okay, so what happened, exactly, the year that 75% of the incoming class ended up in Ravenclaw House and there was exactly one new Hufflepuff out of them all?