This may come as some surprise but over the past five years Gerard Butler has made about half as many movie as Nicolas Cage and Bruce Willis. The latter two aging action stars have both appeared in about 20 movies each, while Butler has acted in a comparably paltry nine, including this weekend's Hunter Killer, a semi-polished but low-rent potboiler about a U.S. submarine involved in rescuing a Russian president from a military coup that could start World War III.

Why do these numbers feel wrong? A skim of IMBD shows that all three stars are making similar types of movies: lots of cop pictures, action pictures, military or military-adjacent pictures. The big difference between Butler and his older counterparts — and why Cage and Willis' output feels so surprising — is in how these movies are released. Most of Butler's movies, even the smaller ones, have been theatrical features. Most of those recent Willis and Cage movies have been gone straight to VOD — video-on-demand, the streaming equivalent of direct-to-video — sometimes accompanied by a regional and/or contractually obligated one-week stint in theaters.

The practice of older stars bypassing mainstream theaters and heading directly to home entertainment isn't new, of course. It's been common practice for decades, as any number of faded action stars could tell you. But Willis and Cage (and other VOD-friendly performers like John Travolta or Wesley Snipes) were bigger stars for a longer period than, say, Jean-Claude Van Damme — or Gerard Butler, for that matter.

Butler's Hunter Killer suggests that the line between movie star and VOD attraction is thinning and blurring more than ever. It comes to its 2,700-screen wide release through Summit Premiere, a direct-to-video-sounding subsidiary of Summit Entertainment (itself a division of Lionsgate), and was co-produced with Millennium Entertainment, which has made plenty of late-period Cage vehicles that barely hit theaters.

Beyond its pedigree, Hunter Killer itself suggests it's only a simulation of a "real" movie. It's professionally made, but not especially skillful. It's diverting, but not wildly entertaining. Dumb, but not insulting. What makes it feel most like a facsimile though is its variety of points of view, as it follows Butler's sub commander and crew, a smaller team of U.S. military forces on a top-secret mission, the obligatory control room back home, and even some Russians-only intrigue. The number of poorly intercut storylines feels like an unwieldy compromise to secure the participation of its actors. Gary Oldman will appear if he can shoot all of his material in a couple of days, in a handful of rooms. Linda Cardellini and Common will do it if they get to play high-ranking intelligence officials instead of love interests. Gerard Butler will do his machismo thing with the bad American accent, but not participate in any heavy action scenes.

Hunter Killer is not appreciably worse than plenty of straight-to-VOD movies, and for that matter better than many theatrical releases (Butler's Olympus Has Fallen series, for example, is both chintzier and stupider). But it's the kind of film that can make the whole system feel arbitrary. Is Gerard Butler a movie star or not? He probably holds less overall name recognition than Willis or Cage, but he's appeared in more hits over the past decade despite scarcely showing better taste or judgment. Is Hunter Killer an old-fashioned B-movie or a failed blockbuster?

Further complicating these questions is the possibility of a VOD exploitation title accidentally becoming a hit. That's not to say that Mandy, a psychedelic revenge thriller starring Cage that came out last month, wasn't ever intended to be good; the director clearly has some chops, and Cage gives one of his best recent performances. But this bloody, nutty, passionate movie attracted such cult buzz that a token theatrical engagement, simultaneous with its VOD debut, morphed into something more like an arthouse release, with moviegoers requesting the movie and theaters requesting more bookings. It's still a small movie, one that never played on more than 100 screens and will probably make less theatrically than Hunter Killer will make on its opening day. But it will do more to burnish Cage's reputation than any of Butler's recent films.

This won't get the next half-dozen Cage projects back into thousands of theaters — or exile Butler from his big-screen career. As strange as it is to see someone like Cage or Willis devote most of their time to VOD programmers, the blurriness of that line makes it easy to step across in either direction, sometimes repeatedly (or even unknowingly). Netflix Originals (granted, a flashier cousin to VOD movies about dirty cops or vengeance-seeking husbands) have corralled Brad Pitt and Will Smith into movies that never had much or any theatrical release.

Sometimes this is used as evidence that star power is on the wane, and it certainly makes the calculus of supposed star worth trickier to perform than ever. But in a way, these difficulties are indicative of a star surplus, not a shortage. Actors don't retire as frequently or early as they did half a century ago, and if Cage or Willis or Travolta have lost some (okay, a lot) of big-name luster, they're still household names. They've chosen to use those names to remain in leading roles as often as possible, even if some of the vehicles are subpar. Doing VOD can certainly feel like a waste of their considerable talents, but it won't keep them from appearing in the occasional studio film or booking a prestige TV show if they decide to go that route.

Maybe Butler, Oldman, and the other name actors inexplicably in Hunter Killer aren't slumming in a thriller that just barely escaped VOD; maybe they're just trying to keep moving.