Rand's challenge was to try and outsmart one of the world's smartest women. He knew she was smarter, and he struggled with it a few times and asked other people's opinions. He then found the answer - 'let her think you'll play her game and then punch her in the face', which is what he did.

If Graendal survived it makes Rand look like an enormous idiot, and it takes Graendal's intelligence to a higher level. She might as well be immortal if she survived, which is why I'm convinced she's dead.

The truth is that Rand did outsmart her.