NBC works with the international federations that govern Olympic sports and the International Olympic Committee to get the most favorable scheduling. For games in Asian locations, NBC’s goal is to have as many marquee sports as possible — swimming, diving, track and field and gymnastics in the summer; figure skating and skiing in the winter — taking place at times when they will be live in prime time on the East Coast. NBC would not necessarily need to cover gymnastics live; in Brazil, it showed the events on a delay of several hours.

Still, scheduling audience-grabbing events in prime time can be a tight squeeze. Events that start at noon in Korea in 2018 would be seen at 10 p.m. the prior day in the Eastern time zone. And NBC cannot get everything it desires in scheduling despite the enormous rights fees it pays; other countries’ networks, including those in Europe, for example, push for favorable scheduling of their own to televise their popular sports.

Neal Pilson, an industry consultant and former head of CBS Sports, said: “If you asked NBC’s preference, they’d probably prefer not to have three straight in Asia, but they bought into the process without knowing where they would be held. But I think NBC will figure out a way to prevail in terms of scheduling.”

Still, even a favorable time zone like Brazil’s did not deliver for NBC as the network had expected. NBC thought that the greater number of live prime-time broadcasts from Rio would produce audiences larger than those amassed for London four years ago. But at 25.4 million, NBC’s broadcast audience fell 18 percent from the 31 million that watched the London Games. It added 2.1 million more viewers from live streaming and Olympic events on the NBCSN and Bravo cable networks. In all, the three sources of viewership did not combine to match London’s broadcast-only performance.

“Television is in a secular decline,” Mr. Greenfield said, adding that viewers increasingly accustomed to binge-watching online series are likely to grow increasingly dissatisfied with NBC’s prime-time model that compels viewers to wait for their favorite sport to be shown.