Watson can't do this: it only buzzes once it has an answer in mind and a sufficiently high confidence interval.
Well, they could have programmed it any way they wanted to. It would have been smarter just buzz in right away given that they knew it would be right most of the time.
Regardless, Watson dominated because it was confident about an answer most of the time before the light turned on. If a human also wants to buzz in right when the light turns on, he or she will always be beaten by Watson. So, the game again boils down to who buzzes in first, regardless of confidence.
