Hank Dolworth, the private eye hero of FX’s terrific new drama Terriers (tomorrow at 10 p.m., FX), is asked if he’s a stupid man.

“I graduated fourth grade okay,” Hank insists.

Hank (Donal Logue from “Grounded for Life”) is not stupid, but nor is he an exceptionally brilliant detective. He just knows his limitations. He and partner Britt Pollack (Michael Raymond-James) are bottom-feeding detectives in Ocean Beach, CA, working without a license - “We find that by not working with one, we never have to worry about losing them,” Hank explains - or much of a plan. Their key assets are Hank’s pickup truck, the cop buddies who will still talk to him since he lost his badge for being a drunk, and the skills Britt picked up in his previous life as a thief. Their own lawyer, who throws them most of their work, dismisses them as small-time.

“We grow two sizes, we might make small-time," Britt acknowledges.

But like the breed of dog that gives the show its title, what these two lack in brains and brawn, they more than make up for in persistence. As the series begins, they stumble onto a big case involving the richest man in town, which leads Hank to suggest, “Maybe we’re actually big time and just didn’t realize it.”

Hank’s last name and Britt’s first name come from, respectively, Burt Lancaster’s character in “The Professionals” and James Coburn’s in “The Magnificent Seven.” The show’s creator, “Ocean’s Eleven” writer Ted Griffin - who produces with “The Shield” creator Shawn Ryan (frequent Joss Whedon sidekick Tim Minear is the #3 man) - has said he wanted “Terriers” to be a mix of private detective tropes and the kind of relaxed masculine camaraderie seen in films like those two, “Butch Cassidy and the Sundance Kid,” “The Great Escape,” etc.

And so much of what makes “Terriers” appealing is that bond between Hank and Britt, and the fantastic on-screen chemistry between Logue and Raymond-James, who are friends in real life and shared a house during filming.

In the series’ opening scene, Hank and Britt are preparing for a job when Hank pauses to tell Britt he has a song stuck in his head. Britt, clearly knowing from past experience what’s coming next, begs Hank not to sing it for him, but Hank goes ahead and hums a few bars of what sounds like The Carpenters’ version of “Close to You” - and Britt can’t help smiling at his pal even as the tune gets lodged in his brain, too. They’re screw-ups, but they’re exceedingly likable screw-ups.

That balance between buddy comedy and hard-boiled drama should be tricky, yet “Terriers” flows easily between the two. Hank seems like a complete bumbler half the time, and yet you feel for him as he pines for ex-wife Gretchen (Kimberly Quinn) or when he commits to bringing down a bad guy at all costs. Logue is better known for comedy, and there’s certainly a a lot of that here (albeit mostly wry, low-key humor and banter), but he’s also delivering a knockout dramatic performance - one that fits comfortably alongside FX’s other leading men. Hank’s a recovering drunk who’s lost everything - job, wife, reputation - and while he can make jokes at his own expense, he’s also deeply ashamed of the man he’s become, and Logue nails it every time he’s asked to take Hank seriously.

Raymond-James works more in the series’ lighter areas, but he’s enormously charming, and the show has wisely given him a girlfriend in Laura Allen’s sensible Katie who really enjoys her man’s ramshackle lifestyle, even as she’d like to see him grow up just a tiny amount.

FX’s last new entry, “Justified,” struggled for a half a season to balance standalone storytelling with the kind of longer arcs viewers have come to expect from the FX brand. Since Ryan more or less invented that brand with “The Shield,” “Terriers” comes out of the gate knowing exactly when to shift between the two. There’s a complicated ongoing storyline involving the wealthy land developer, but there are also running personal subplots (Hank’s desire to buy the house he and Gretchen lived in, Britt trying to do right by Katie) that are there to help anchor the done-in-one cases.

And those cases are a potent reminder of how compelling the PI genre can be when done straight. The third episode, for instance, features a terrific guest turn by Olivia Williams from “Dollhouse” as the allegedly cheating wife of a client, in an easy money case where nothing turns out to be as it seems. Though it’s clearly a modern story, it feels like something that Humphrey Bogart or Paul Newman or Stacy Keach might have been at the center of decades ago.

“Terriers” comes with the amusing tagline “Too small to fail.” It’s not an ambitious show. It doesn’t have the historical sweep and dazzling visuals of something like HBO’s upcoming “Boardwalk Empire.” Yet in trying to tell good old-fashioned detective stories featuring a pair of leads I kept wanting to spend time with, it quickly joined “Boardwalk” as one of my two favorite new shows of this fall.

More on "Terriers": Interview with stars Donal Logue & Michael Raymond-James |  Interview with producers Shawn Ryan & Ted Griffin

Alan Sepinwall may be reached at sepinwall@hitfix.com