A Watson that knows 70% of the answers will beat a human who knows 90% of the answers, purely due to better reflexes. Of course, buzzer skill is partly how KenJen won so many games, so I'm not complaining. Just not AS impressed by Watson as some people.
Except that it's not just reflexes. Watson has to compute the answer before the humans. That's no small task. This video is a great technical explanation of how it works:
