Ask movie buffs to name their favorite directors, and you’ll probably hear a lot of names you recognize–Kubrick, Hitchcock, Welles, Coppola, Scorsese, etc. Probably very few people will mention Joseph Sargent. That is unfortunate, because he’s done some pretty dazzling work in Hollywood, and at age 88 has more impressive credits than many directors could hope to have in a career.

Sargent is definitely one of those workhorse directors as opposed to the ostentatious, “vision” or “message” auteurs like Kubrick or Scorsese. Probably his best movie is the tense, gritty 1974 urban thriller The Taking of Pelham One Two Three, with Walter Matthau and Robert Shaw. But he also directed one of the very first episodes of the original Star Trek, “The Corbomite Maneuver” (with a pre-pubescent Clint Howard as a powerful alien), and the highly underrated TV miniseries World War II: When Lions Roared, featuring Earth-shaking performances by John Lithgow as FDR, Bob Hoskins as Churchill, and Michael Caine as Stalin.

Sargent also directed what is universally regarded as one of the worst films of all time: the desperately, brain-destroyingly awful Jaws: The Revenge. How could a director who scored so high with Pelham 123 sink so low as to give us Jaws: The Revenge? I am curious about that question, so let’s do a brief comparison of the movies.

The Taking of Pelham One Two Three (1974)

Pelham 123 fits squarely in the genre of “New York Hell” movies that were very popular in the late 1960s and up through the mid 1970s. These films depict New York City as a seething inferno of danger, usually from crime (think Death Wish, The French Connection) but sometimes from simple nihilism and alienation (think Network). In this film, a group of terrorists with color-coded names–Mr. Brown, Mr. Gray, Mr. Blond, etc.–seize a New York subway train with machine guns, stall it in a tunnel, and then blackmail the transit authority for $1 million, or they’ll start killing passengers.

The movie is as tense as they come. Robert Shaw plays the terrorist chieftain with a cold, ruthless aplomb. Walter Matthau is the transit boss who has to negotiate with him–and ultimately outsmart him. Indeed, the movie’s strength is that it’s less of a cops-versus-bandits story of muscle and bullets, and much more of an intellectual cat-and-mouse game, based on trying to outwit the terrorists and anticipate their next move. The film, at 104 minutes, feels like about 20. It moves very fast, never lets up and is full of standout performances. I think it’s one of the best films of the ’70s.

Why does it work? A good script doesn’t hurt, but it’s really the direction that works here. Sargent knew how to make a film, technically, but he also knew how to coax good performances out of experienced actors, and he also seemed to know how to stay in the background to let them do their thing. The tenseness and technical prowess of the movie is impressive. It works together like a well-oiled machine.

So what happened?

Jaws: The Revenge (1987)

The third sequel in the Jaws franchise is limp, lackluster and utterly laughable. It centers around Ellen Brody, played by Lorraine Garry from the first film, who’s the only one of the original Jaws cast who signed up for the fourth installment. After her son, an Amity policeman, is hideously torn apart by a shark on Christmas Eve (no…really?) she gets it in her head that a shark is pursuing her and trying to destroy her family. She flees to the Bahamas, where her other son is working as a marine biologist, and of course the shark does pursue her–rather improbably–and proceeds to terrorize her and her new lover, a charter pilot named Hoagie (yes, that is his name), played by Michael Caine.

Jaws: The Revenge is absolute torture to watch. It’s so abysmally stupid that it insults your intelligence at every turn, from the low-rent mechanical shark effects (which seem to have actually regressed since 1975 when the first film was made) to the cringe-inducing dialogue and the blank-stare performance of Lance Guest as Mike Brody. It’s barely 90 minutes but even that is generously padded, including with lame clips from the first movie that Ellen Brody “remembers.” The late Roger Ebert, who gave the movie zero stars, famously called the direction of the action sequences incompetent, lacking establishing shots and other orientation markers. That’s a pretty low arrow to fling at the experienced Sargent, whose film credits go back to the 1950s.

Why are these movies so wildly divergent in quality?

The big question: how could you, Joe? As different as these films are, I think what could explain their extreme differences is the style of Sargent’s direction, which seems to be, get the job done at all costs.

Think about it. For Pelham 123 he had a good script, great actors, terrific location, and a tense storyline. His job was to grit his teeth, shoot it on budget and on time, cut the thing together as tightly as possible and make it work. I don’t think Sargent was thinking about making a great film, one of the true triumphs of 1970s crime movies. I think he was thinking about getting the movie done as best, as fast, and as cheap as he could.

You know what? I think he thought exactly the same thing on Jaws: The Revenge. Whether signing on to the movie in the first place was his mistake–and that’s debatable–he was handed a terrible script, mediocre actors (except for Gary and Caine), so-so locations, and a ridiculous storyline that gaped with egregious plot holes. His job? Grit his teeth, shoot it on budget and on time, cut it together as tightly as possible, and limit the damage. Maybe Jaws: The Revenge was a doomed project from the start. But as bad as it is, think about this: with a lesser director, might it have been even worse?

I think bad movies often tell us more about the art of cinema than good ones do. In the failure of Jaws: The Revenge I think we can witness the brilliance of a director who produced something as great as Pelham 123. If I were Joseph Sargent, I wouldn’t even let having my name on one of the worst pieces of crap ever made in Hollywood bother me a bit. I’d go on to the next project, the next movie, and make it better next time. What else can you do?

Joseph Sargent hasn’t made a film since 2008, but he is currently the filmmaker-in-residence at the American Film Institute.