LONDON — Given that NBC has produced every Summer Olympics since 1988, there should be little mystery to the network’s tried-and-true approach to broadcasting the London Games, which begin on NBC, if not officially, with the Opening Ceremonies Friday.

The viewership, which has been as high 60 percent female during previous Games, knows what it is going to get — human-interest stories galore, for starters. Bob Costas is the familiar face of the coverage, returning as the prime-time host. Costas will be joined by co-hosts Matt Lauer and Meredith Vieira during the Opening Ceremonies, with Tom Brokaw and Ryan Seacrest providing reports.