The world chess champion, Garry Kasparov, and the most powerful chess computer yet invented drew last night's fourth game in their $500,000 six game challenge in Philadelphia.
In the most exciting game so far, the IBM super computer, Deep Blue, sacrificed a pawn for dynamic tactical play. Kasparov then gave up material to force a draw after 50 moves and 41/2 hours' play. Man and machine are now tied at 2-2 after one win each and two draws.
Deep Blue made chess history on Saturday when it convincingly beat Kasparov in the opening game. It was the first defeat of a reigning world champion by a computer in a championship format.
The fifth game is due to be played tomorrow.