"I think they sense that people will get freaked out by how well it's doing and how well it can approximate a human," he said.
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.