Now that I think of it, Quirrel watched over Harry as he felled a bunch of trees in Precautionary Measures pt.2. And that involved partial Transfiguration.
So was Voldemort really unaware that Harry could Partially Transfigure Things? Or did he only underestimate what could be done with that?
From our perspective, yes, I agree that it is obvious, but from Voldemort's perspective at the time, Partial Transfiguration just isn't something that exists; there's no reason to have it as a prominent hypothesis to explain Harry's cutting down trees. It's much simpler to assume that Harry had just figured out a more efficient variant of the Severing Charm, or something similar. As Voldemort himself said in chapter 108:
...experience has taught me that such puzzles are far harder to solve when you do not already know the solution...
[edited]
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 117.
Plans for next chapter release:
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)