Reasoning by analogy is great, but at some point you have to be able to demonstrate sufficient isomorphism to justify the analogy.
What I'd be trying to determine by researching Battle Magic is precisely whether your analogies to chess and TKD hold. As opposed to, for example, the analogy Aharon used in the first place of taser vs. revolver.
Trivial example: if it's just as easy for a shield to block a "kill" spell as a "sleep" spell, then you can feint with a sleep spell just as effectively... whichever one hits me, I lose, so I have to dodge them both. In that world, your TKD analogy doesn't hold, and Quirrel's claim is unconvincing.
I don't know enough about the HPverse to know if the analogy holds there, nor am I sure Harry does, which is why I'm uncertain. (By contrast, I still have no firm idea what Quirrel is doing with the flask in Bella's cell, but I'm fairly sure that Harry has a firm idea that the audience simply hasn't been informed of.)
Trivial example: if it's just as easy for a shield to block a "kill" spell as a "sleep" spell, then you can feint with a sleep spell just as effectively
Right, not the case in HPverse - the killing curse is special because it's the only one that can't be blocked (though it's pretty vague what "can't be blocked" means)
- This thread has run its course. You will find newer threads in the discussion section.
Another discussion thread - the fourth - has reached the (arbitrary?) 500 comments threshold, so it's time for a new thread for Eliezer Yudkowsky's widely-praised Harry Potter fanfic.
Most of the paratext and fan-made resources are listed on Mr. LessWrong's author page. There is also AdeleneDawner's collection of most of the previously-published Author's Notes.
Older threads: one, two, three, four. By tag.
Newer threads are in the Discussion section, starting from Part 6.
Spoiler policy as suggested by Unnamed and approved by Eliezer, me, and at least three other upmodders:
It would also be quite sensible and welcome to continue the practice of declaring at the top of your post which chapters you are about to discuss, especially for newly-published ones, so that people who haven't yet seen them can stop reading in time.