Gross viewership has the drama nearing the HBO record set by "The Sopranos" in 2002 while solidifying its status as one of the most formidable series currently on TV — besting most broadcast and cable DVR stats.

Game of Thrones isn't just the biggest thing on HBO. It's now one of the most watched series on TV.

The fourth season of the pay cable net's crown jewel is currently averaging 18 million gross weekly viewers -- that figure, courtesy of HBO, includes first-runs, encores, HBO GO and On Demand views -- more than doubling its already formidable Sunday outings that have been holding steady around 7.2 million viewers for the past month.

Huge by HBO standards, it's approaching The Sopranos' 18.2 million watermark set by its own fourth season prior to Nielsen's 2004 measurement change. Passing that number, which it might very well accomplish after the book closes on the fourth season, would make this run of Game of Thrones the most watched of any original in network history.

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Its competition on the rest of the dial is not as crowded as one might think. Over on the Big Four, where live-plus-7 data is the most comprehensive thing going, the recent season ended with only three series averaging north of 18 million viewers: Sunday Night Football, NCIS and seemingly insurmountable Big Bang Theory (23.1 million viewers, if you're keeping track). Game of Thrones now tops NBC's The Blacklist as well as marquee reality shows The Voice, Dancing With the Stars and American Idol.

[UPDATE: At the time this story was published, The Walking Dead's most comparable rating was not available. With replays, on-demand and TV Everywhere views added to live-plus-7 returns, the series' fourth season averaged just north of 28 million weekly viewers.]

And look at The Walking Dead. TV's gold standard, thanks to its dominance among adults 18-49 (peripheral info to ad-free HBO), currently ranks as cable's most watched television series. The recent season averaged 18.4 million viewers in live-plus-7, placing another record well within Game of Thrones' sights.

Game of Thrones' season-to-season bump, with two episodes remaining, stands at 25 percent. Its unique and thus-far unflappable trajectory most closely parallels that of The Walking Dead. So it seems fitting that the pair head into their respective fifth seasons so closely aligned.

It's difficult -- and, in fact, quite problematic -- to compare HBO to any network other than itself. The HBO Go app, aggressive replays over multiple sisters (HBO2, HBO Latino) and the limiting nature of pay cable create a very different standard for measurement. (Parent company Time Warner most recently put the domestic subscriber count at 43 million, a hair shy of Netflix.)

But this latest growth for Game of Thrones pushes it into an intimate pantheon of mega-hits that begs comparisons.