AMC’s The Walking Dead shouldn’t be a hit. Neither should ABC’s Dancing With the Stars or Discovery’s Deadliest Catch. In fact, we’ve come up with a list of nine hit TV shows that, when you really think about it, shouldn’t be successful. This isn’t meant to insult these shows or suggest they haven’t earned their popularity. Just the opposite. They deserve props for delivering a big audience despite having some element that conventional TV industry wisdom says should be a deal breaker. Here’s the nine inexplicable hits, starting with…

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Dexter

Hit proof: The Showtime drama has increased its ratings every season (hitting 2.3 million viewers for its recent premiere telecast) and is the network’s most popular series.

Why it shouldn’t work: We all know Dexter Morgan is a serial killer, but hold on. Take a step back. We’re rooting for somebody whose only joy in life is stabbing people to death. On any other movie or show, that’s your detested villain. Sure, he targets bad guys, but his addiction manages to get innocent people murdered too, such as his loving wife Rita and his former colleague Sgt. Doakes. Yet we still root for him!

Why it does work: Star Michael C. Hall has just the right combination of charm and creepiness. Plus, a little voice-over and dark humor goes a long way. By listening to Dexter’s narration, we become his accomplice. By adding humor, we don’t take his body count too seriously. Imagine a dead-serious version of Dexter without voiceover — just a guy going around killing criminals in Miami. Some of you might like that idea better, but I bet it wouldn’t be a hit.

Deadliest Catch

Hit proof: Often topping 7 million viewers, it’s one of the most successful cable reality shows of all time.

Why it shouldn’t work: It’s also one of the most repetitive. How many times can you watch crabs being hauled onto a boat? If you’re a fan: Hundreds.

Why it does work: Crab fishing is literally like a televised slot machine. Every time they reel in a “crab pot” you get a different, unpredictable result, what those in the casino psychology business call a “variable payout.” Sometimes a ton of crabs spill out onto the deck like coins in a tray (ding! ding! ding!). Other times, nada. The fishermen are colorful too. Deadliest helped pioneer the blue-collar rural workman reality show which is currently ruled by Discovery’s hugely popular and similar Gold Rush.

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Glee

Hit proof: One of the biggest and most influential new hour-long shows to come along in recent years.

Why it shouldn’t work: There hadn’t been a hit scripted TV musical series in decades (1982’s Fame, best I can find, was the last), and there’s been a few attempts (Viva Laughlin, Cop Rock, Hull High).

Why it does work: Two crucial decisions: Using popular songs that viewers already like (instead of original songs, like on Cop Rock) and the high-school glee-club setting (which, like Fame, gives a musical context to the story rather than, say, courtroom lawyers breaking out into song). Disney Channel’s High School Musical movies paved the way, but Glee added a snarky wit and more heart that made it work as a weekly show.

Dancing With the Stars

Hit proof: Still one of the most-watched reality shows on TV after 15 cycles, averaging 14.3 million viewers this season including DVR.

Why it shouldn’t work: Let me get my list. First, it’s called Dancing With the Stars! You’re used to that name now, but remember the first time you heard it seven years ago? It sounds like a show from the 1950s airing after Wagon Train. Two, it’s about ballroom dancing. The only televised tango when this show launched was on low-fi networks like PBS. Three, several shows that have tried to replicate Dancing‘s celebrity-and-a-pro pairing format have failed, like Fox’s Skating with Celebrities, ABC’s Duets and NBC’s Stars Earn Stripes.

Why it does work: It’s dancing — man’s first form of communal entertainment from back in the caveman days. That primal appeal doesn’t change no matter how many sequins you add. Also, viewers enjoy watching celebrities compete against each other in a challenging new environment (one reason Celebrity Apprentice works too).

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Duck Dynasty

Hit proof: A&E’s little reality show recently beat out high-profile shockfest American Horror Story to top Wednesday night on cable, delivering well over 3 million viewers per episode.

Why it shouldn’t work: It’s about a redneck family living the swamp managing a duck call business and going hunting. (OK, so for many of you, that’s why it should work).

Why it does work: Call it Pre-Modern Family. It’s like any classic family comedy — a likeable core of warm-hearted people. The combination of Christian values and southern-fried fun gives this show plenty of red state appeal. Though TLC’s Here Comes Honey Boo Boo is somewhat similar and probably even more inexplicable to most readers.

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The Walking Dead

Hit proof: AMC’s hit is currently the highest-rated drama on TV in the adults 18-49 demographic (a 7.2 rating including both repeats and DVR).

Why it shouldn’t work: Put away those machetes and cross-bows and hear me out! What’s cool about TWD might seem obvious. It’s easy to forget how low industry expectations were before it first premiered a couple years ago. And if you told a TV executive the current third season storyline, their expectations would have been even lower. TWD is totally grim, extremely gory, with a cast that looks pretty awful most of the time. Characters are getting rapidly killed off (including the likable non-Lori characters). Perhaps the most unconventional aspect is that nobody seems to have any real hope for a happy ending. Popular stories almost always tease viewers with a light at the end of the tunnel, even if the characters ultimately don’t survive. But on this show, things just keep getting worse, with no real expectation of improvement. It’s like watching people starve to death, plus zombies.

Why it does work: Because the show is so well done, extremely suspenseful and keeps us glued precisely because it breaks so many TV rules.

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Finding Bigfoot

Hit proof: Animal Planet’s series just returned to 1.3 million viewers. Not big numbers, but it’s a lot for Animal Planet, especially considering the next point I’m going to make.

Why it shouldn’t work: Spoiler alert: They’re never going to find bigfoot.

Why it does work: Successfully teases the viewer that there’s a Squatch right… around….that next… tree. Damn! Maybe the tree after that? Gotta give credit where it’s due: There wouldn’t be a Finding Bigfoot if not for Syfy’s Ghost Hunters, a huge hit by any cable standard, which pioneered this genre. Finding Bigfoot makes the list because it’s a fresher version of the same idea and, if anything, even more inexplicably a hit. Ghost Hunters and its knock-offs all use the same tricks, but at least viewers are motivated for the TAPS team to prove there’s an afterlife (because, you know, that would be nice). Not sure how humanity would benefit from seeing Bigfoot; it’s worth a week of CNN headlines at best. I’m now waiting for a Locating Loch Ness spin-off.

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NCIS

Hit proof: In terms of total viewers, it’s the most-watched drama on TV, currently averaging 22.6 million viewers including DVR.

Why it shouldn’t work: Before you comment: I know that NCIS should not be a flop. It’s inclusion on this list is admittedly a stretch. But there’s also a reason it’s here. NCIS mystifies a lot of people not because it’s a hit, but because it’s this big of a hit (and no, the show’s fans are not just “old” people — NCIS does really well among adults 18-49 too). For many, NCIS is so corny that it’s downright difficult sit through compared to other procedural dramas, particularly for those of us in the TV industry and the media. I started asking insiders during get-to-know-you lunches if they watched NCIS just to see how long I could go before finding a person in Hollywood who watched TV’s most popular drama. It took two years. I’m sure that says worse things about the industry — being unable to appreciate such a popular title — than it does about the show.

Why it does: Here’s some explanation from Slate: “Amiable, unpredictable, and no more outlandish than any other prime-time fantasy about battling evil—gives you a lot for your 44 minutes. Mingling elements of a hardy cop show with those of a svelte espionage drama, segueing from macabre moments at the autopsy table to small giggles of office comedy, it’s lively with variety … The formula is so elastic that it doesn’t resemble a formula.”

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Every Cooking Competition Series

Hit proof: Some of the most popular reality shows — Hell’s Kitchen, MasterChef, Top Chef — are cooking competitions.

Why it shouldn’t work: All these shows violate a major competition TV rule of success that goes back to early TV game shows. On singing shows like American Idol you can judge the singing for yourself. On dance shows you can judge the dancing. On romance shows you can judge the bachelor’s dates. You may disagree with Simon Cowell, but you can form your own opinions using the same information. But on cooking competition shows, you cannot taste the food — and that’s mainly how judges determine who wins. There is no, as reality TV executives call it, “play along” for the home viewer. For all we know, Tom Colicchio and Gordon Ramsay have horrible taste and make dreadful decisions.

Why it does work: Credit humans for being imaginative. With enough perfectly composed loving shots of gorgeous dishes combined with sensuous descriptions, we can almost taste that lemon vanilla créme with mint purée and hazelnut sable. Also, sex and eating are two of the most primal bodily urges. Many enjoy watching sex, but you can’t really show that on TV. Eating is the only basic physical need that TV can depict in all its naked glory.*

That’s it! Thanks for reading. I bet you were expecting Two and a Half Men, right? There’s no comedies on the list — I figured humor is too subjective to go around saying that a certain style isn’t funny enough when, obviously, it apparently is. What show would you add to this list?