finally in the second round of jeopardy! it was man versus machine. who won? machine kicked our butts. it was rough. watson, the computer, got 25 questions right while human champs, ken jennings and brad rutter, only got a total of five right. how does watson do it? here s david muir. let s take alternate meanings for 200, alex. reporter: call it man versus machine. superstar contestants against the supercomputer. watson was off and running. losing to him by 0.01 seconds. watson? who is michael fephelps? go again. correct. reporter: and today when we saw what makes watson tick, he s loaded with a world of data. ten refrigerator size racks of servers. when alex delivers the clue to the humans, a text of that clue is sent to watson, who searches his hard drives for the answer. a long ways since that first computer with the hard drive in the 60s could store about one