As IBM's Watson headed into its final match against Ken Jennings and Brad Rutter, it seemed to many that the game was locked up. Walking out of the session following Watson's dominant game-one performance, IBM Chairman suggested to colleague that maybe the team "should have dialled it down a little." Maybe he was joking, but Palmisano was sitting with Sony executives, who could not have been happy about Watson's day-two shellacking, which threatened to drain the Man vs Machine match of its competitive excitement. But the IBM team led by David Ferrucci knew all too well that Watson was still vulnerable. To win, though, one of the human players would have to get lucky and bet audaciously. (This was the formula Greg Lindsay used in his three wins against Watson in sparring matches a year ago.) The key was Daily Doubles. To win, either Jennings or Rutter had to earn a quick $10,000 or so, and then double it in a Daily Double, and then double it again in another one. Only by this type of doubling could one of them get to $40,000 or $50,000, and erase the lead Watson had established in game one (about $30,000 ahead of Jennings, $25,000 ahead of Rutter.) So the game would feature a relentless hunt for the three Daily Doubles on the board, one in the Jeopardy round, and two in Double Jeopardy. If Watson landed on them, the machine would bet small. It was not about to risk its lead. The key for Watson, just like a basketball team playing against the clock, was to deny its opponents these chances to catch up. UPDATE: Now I can say, as most of you already know, that Watson won. Here's Arik Hesseldahl's account in AllThingsD, along with his podcast with me. I'm heading to an IBM event tonight. I'll watch the game with at their NYC headquarters, and afterwards the company will distribute copies of the book. It goes on sale tomorrow in books stores, and the update with the last chapter should be arriving shortly. By the way, here are some recent articles. In an op-ed in the Boston Globe, I argue that Watson will be our underling, not--as Ken Jennings might joke--our overlord. In the LA Times, I write about what will happen to franchises like Jeopardy and, equally important, our minds, as the Watsons of the world progress.