system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does a punch to the chin knock one out but a punch to the head might not?
gpt
It’s about getting the skull to snap back. You get knocked out when you brain smashes against the inside of your skull, and a punch straight to the head probably won’t generate enough rotation to do that, but a punch to the chin will rock your skull backwards and your brain will hit the back of your head.