Watson, named after IBM founder Thomas J. Watson, was built by a team of IBM scientists who set out to accomplish a grand challenge - build a computing system that rivals a human's ability to answer questions posed in natural language with speed, accuracy and confidence. Watson competed on Jeopardy! against the show's two most successful and celebrated contestants - Ken Jennings and Brad Rutter - on February 14, 15 and 16, 2011. The Jeopardy! format provides the ultimate challenge because the game's clues involve analyzing subtle meaning, irony, riddles, and other language complexities in which humans excel and computers traditionally do not.