The hard-luck brawler of the Aussie mixed-martial arts thriller “Beast” finds himself working for next to nothing on a Sydney harbor trawler at his low point in the movie.

He’s a “Jonah,” his jerk skipper insists. Bad luck. No “fish” in their traps.

And I couldn’t wait to get home to see what “fish” those Aussies catch in what look like your average crab trap. Hey, I did a year in Kodiak, Alaska. That makes me an expert.

But yes, they do catch “fish” in such traps down under. So much for making fun of the screenwriters not doing their homework.

Ah, but not so fast. Russell Crowe and David Frigerio co-wrote this generic to the point of tears “fight picture.” And for the life of me, I can’t find much that passes for “homework” in it.

Crowe plays the bulky, crutches-using old trainer who teaches his charges one credo.

“If I am breathing, I can think. If I can think, I can WIN.”

The “Cinderella Man” veteran wrote himself (I’m guessing) a couple of pithy lines. Time is “moments and memories,” his grizled trainer Sammy philosophizes. “If you don’t take the moment, you don’t get the memory.”

That doesn’t compensate for a movie whose Big Third Act Fight sees the Oscar winner watching the brawl on a TV set, muttering “He’s GOT him!” at the screen several times, earning his writing and acting credits the easiest way possible.

It’s difficult to do much new with a fight picture — be it boxing, wrestling, kung fu or MMA — as the genre grinds through its third century on the screen. And the Australian MMA milieu of “Beast” is about all that sets it apart from the hundreds of fight films that preceded it.

There’s a pregnant wife (Kelly Gale) who cries “You PROMISED” when her long-in-the-tooth and retired fighter Patton (Daniel MacPherson) elects to take off his shoes and put on the tiny gloves and strut into the octagon again.

There’s the kid brother (Mojean Aria) who followed Patton into the sport, and pays a high price. An unscrupulous promoter (Luke Hemsworth) sleazes our broke trawler deck hand into fighting aagin.

The foe, the Warrior Xavier Grau (Bren Foster) is a dirty eye-gouger/late hit thug seemingly two weight classes above our hero, and several classes more above his skinnier kid brother.

And Crowe plays the old trainer whom Patton once let down, the guy who won’t train him because “He’s not no engine. He’s got no urgency. You can’t coach heart.”

Which is why the trainer’s scrappy, tattooed ex-fighter daughter (Amy Shark) takes the job.

The fights are savage enough. But if you’ve ever seen one or two ring or octagon movies, there’s nothing at all new here. I don’t know how to be more blunt than director Tyler Atkins and crew don’t show us anything that might hold ones’ intellectual or empathetic interest.

You can count the roundhouse swings-and-misses in the fight choreography, because that’s what the brawlers do — “One, two, three, four, NOW I hit YOU, right?”

MacPherson, Crowe’s co-star in “Poker Face” and “Land of Bad,” has the right look and sound, but lacks the presence to carry a movie, at least the way this one is plotted and characterized.

I thought I was settling in for something fresh, but the working class poverty is well-furnished and familial and entirely too tidy compared to “Rocky,” the underdog reaching for revenge and/or glory underwhelms and the darkest moments don’t move or touch the viewer in any meaningful way.

But Crowe’s here, and he got the film made. Frankly, he’s more interesting as an epicurean exorcist on a Vespa than he is lurching into and out of scenes here.

Rating: R, graphic, bloody violence

Cast: Daniel MacPherson, Bren Foster, Kelly Gale, Mojean Aria, Luke Hemsworth and Russell Crowe.

Credits: Directed by Tyler Atkins, scripted by David Frigerio and Russell Crowe. A Lionsgate release.

Running time: 1:53