Why is the 1980 gold medal match in hockey called the 'Miracle on Ice'?

The US Olympic hockey team was a heavy underdog against the Soviets in 1980, and their victory over the Soviets was a surprise to nearly everyone. As the game concluded, Al Michaels, the play-by-play announcer for the game, exclaimed "Do you believe in miracles? Yes!', and because many people around the world watched the game on television, the game became known as the 'Miracle on Ice'.