I'd say this only holds for ~70%, although it's likely geographically skewed - I'm in Seattle, you're in SF. I've interviewed (and been hired, and been success

I'd say this only holds for ~70%, although it's likely geographically skewed - I'm in Seattle, you're in SF. I've interviewed (and been hired, and been successful) at many great companies where we didn't do specific algorithm implementations on a whiteboard during the loop. I would certainly not throw out a promising candidate because they couldn't remember specifics on a certain algorithm.