Still, Rutter said, despite its mistakes, Watson is a very powerful computer.
"I think humans will be surprised," he told ABCNews.com. "Especially because it's just "Jeopardy!" clues like you see every day on the show. To see a computer actually figuring it out, with all the little twists and turns and puns that they like to get in there, even factoring those in. To see how well Watson is doing, I think might scare some people."
But regardless of whether Rutter, Jennings or Watson wins the match, Rutter said, no one really loses.
"Ken and I are representing humanity in this thing but, at the same time, Watson was developed, built, programmed by human beings," said Rutter. "So I think humanity wins no matter what happens."
And beyond even that, Jennings said that playing the world's most sophisticated computer gave him a new appreciation for the humble human brain.
"I was impressed at the end that the human brain -- just a few dollars worth of water and salt and protein and whatever else we have in our skulls -- that that could hang in there and play at the same level as this jillion-dollar computer the size of a room," he said. "It says a lot for the human brain that with what we have we can hang with the world's most powerful computer. It's sort of a newfound respect for what our heads can do, which we take for granted sometimes."
The Associated Press contributed to the report.