On this day in 1996, world chess champion Garry Kasparov defeated a computer, IBM’s Deep Blue, after a six-game match in Philadelphia, Pennsylvania. "It was as tough as a world championship match," Kasparov said after his win. "And believe me, I played very, very seriously." One year later in 1997, Deep Blue defeated Kasparov in a rematch. Watch World News Tonight's report on the triumph. https://abcworldnewstonight.visitlink.me/g2ji6n | ABC World News Tonight with David Muir