As recently as 1998, every show nominated for the best drama series Emmy was recognized for a season comprising at least 20 episodes. Last year, however, the episode counts of the nominated seasons were eight (Netflix's Stranger Things), 10 (AMC's Better Call Saul, Netflix's The Crown, Hulu's The Handmaid's Tale and HBO's Westworld), 13 (Netflix's House of Cards) and 18 (NBC's This Is Us). This is the new normal.

In the early years of TV, the broadcast networks commissioned weekly episodes year-round, apart from summer, resulting in 39-episode seasons. That volume proved expensive and a grind for talent, so, by the 1970s, the default number shrank to 22 or 24. But, even at that figure, rare was the show that could consistently sustain quality and interest. That's why some started experimenting with 13-episode seasons — shows that could run uninterrupted for a quarter of the year.

With the onset of cable, outlets like HBO and Showtime ­— which depend on subscribers, not ads, for revenue — shifted the priority to creating a broad range of content that would attract and retain a variety of viewers, rather than worrying about episode counts. At HBO, Chris Albrecht approved a final season of The Sopranos split into two parts — essentially two seasons, one that ran 12 episodes and the other nine, and both snagged drama series noms. And after moving to Starz, he ordered eight-episode seasons. There were clear financial reasons for doing this: Making shows with fewer episodes allows a network to make more shows, which, in turn, means a broader array of offerings for potential subscribers.

Streamers — also subscriber based — further changed the game. They clamor to license shows of any length while also putting out original content that doesn't have to adhere to any episode count or time slot (in fact, they tend to release all of a season's episodes at once).

While some networks still hope to find shows worthy of 24 episodes, most that have gotten a taste of shorter seasons of drama series no longer wish to make lengthier ones. Indeed, many viewers now feel overwhelmed at the time commitment that 20-plus episodes demand when there are so many shows to watch. And the appeal to a big star of doing a quality TV drama — at a time when prestige film is on the ropes — is greater when one knows one will still be left with time for other pursuits.

This all explains why the last five drama Emmy winners were two half-seasons of Breaking Bad (eight episodes each), two 10-episode seasons of Game of Thrones and a 10-episode season of Handmaid's Tale. Thrones' currently eligible seventh season contained just seven episodes, and its final season, due in 2019, will have six.

It also explains the recent resurgence of limited series (e.g., Hulu's The Looming Tower) and anthology series (e.g., FX's American Horror Story), which had been so endangered that in 2011 the TV Academy combined the miniseries and TV movie categories. They came back strong and have had their own category again since 2014, with some proving so popular that they later morphed into regular drama series (e.g., PBS' Downton Abbey and HBO's True Detective and Big Little Lies).

Could we be headed toward the British model, short-order series? Those have seasons that are three to six episodes apiece. The TV Academy hasn't figured out what to make of them — classifying BBC America's Luther and PBS' Sherlock, for example, as limited series, or episodes thereof as TV movies — but they've been nominated repeatedly (and last year's TV movie Emmy went to Netflix's Black Mirror episode "San Junipero").

Such formats may make more sense for the ADD era in which we live — a 2015 study concluded that humans now have a shorter attention span than goldfish — as does Jeffrey Katzenberg's big idea for the future: not just fewer episodes, but shorter ones. Before we know it, the content we crave might, in some ways, look like the commercials many now avoid.

This story first appeared in a June stand-alone issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.