On January 14, 1973, NBC's telecast of Super Bowl VII between the Miami Dolphins and Washington Redskins was watched by approximately 75 million viewers. NBC's telecast of Super Bowl IX between the Pittsburgh Steelers and Minnesota Vikings had an audience of approximately 78 million viewers. The 1973 game, called by Curt Gowdy and Al DeRogatis, was the first Super Bowl to be televised live in the city where it was being played. Despite the league's unconditional blackout rules that normally would have prohibited the live telecast from being shown locally, the NFL allowed the game to be telecast in the Los Angeles area on KNBC on an experimental basis when all tickets for the game were sold. The league then changed its blackout rules the following season to allow games sold out at least 72 hours in advance to be televised in the host market. No subsequent Super Bowl has ever been blacked out in the city it has been played in, since all of them have been sold out.