Watson Takes Lead in Day 2 of 'Jeopardy! Match

Feb. 16, 2011— -- IBM's super computer Watson clobbered the competition on night two of the three-day man vs. machine "Jeopardy!" challenge.

For most of the half-hour program Tuesday, the computer dominated the board, leaving "Jeopardy!" all-stars Ken Jennings and Brad Rutter in the dust. Between them, the human contenders successfully answered only a handful of questions.

The final score? Watson in the lead with a whopping $35,734, Rutter in second place with $10,400 and Jennings bringing up the rear with $4,800.

Despite Watson's impressive performance, he did leave the audience with a bit of a head-scratcher.

During Final Jeopardy, the trio was presented with the clue: "Its largest airport is named for a World War II hero; its second largest, for a World War II battle."

Rutter and Jennings successfully answered "Chicago," but Watson offered the iffy "Toronto?????" The response was even more curious, considering the category was "U.S. Cities."

In an explanation on its blog, IBM said that even its own developers were puzzled by the mistake.

David Ferrucci, the manager of the Watson project at IBM Research, said that several factors likely confused the machine. For starters, not only was the category name ("U.S. Cities") not included in the actual clue, Watson has been trained to downgrade the significance of the category because answers don't always exactly fit the category.

Ferrucci also said that Watson might have been thrown off because there are some cities named Toronto in the United States and even Toronto, Canada, includes a U.S. Major League Baseball team. Still, he added, the mistake wasn't entirely discouraging because Watson had little faith in its answer, registering a 30 percent confidence level.

Ultimately, the machine's wrong answer barely left a dent in its total winnings because Watson cleverly wagered only $947.

IBM's Watson gives one look at smart machines, click HERE for a few more.

The matchup, which was taped in January, aired on national television for the first time Monday night and wraps up tonight. The winner of the challenge will take home $1 million.

For the past four years, top artificial intelligence researchers at IBM have been preparing their mega-machine, Watson to compete on "Jeopardy!" against all-time champions Jennings and Rutter.

After Monday night's round, Watson and Rutter were tied in first, with Jennings in third place

In an interview with ABCNews.com last week, Jennings said that when "Jeopardy!" first called him a couple of years ago to let him know that IBM was working on a game-show machine, he said he was "skeptical."

As a former computer programmer himself, he said, he knew the computer's limitations and doubted if IBM actually could pull it off.

But when he watched taped matches of Watson playing against top human contestants, he realized that beating the computer was hardly a foregone conclusion.

"Clearly, it was playing at a very high level. It sort of effortlessly handled the kinds of things I thought computers couldn't do," he said. "It could understand wordplay, it could understand things that were more conceptual than a single fact."

But when the machine gets something wrong, Jennings said, "it gets it spectacularly wrong."

For example, Jennings said an IBM developer told him that when asked for the Russian word for "goodbye," Watson gave the answer "cholesterol."