Why two blokes digging up ring pulls is compulsive viewing

IS "gentle comedy" another way of saying that basically a show isn't especially funny?

It might raise a wry smile, rising to the occasional parp of laughter. But by the main measure of a sitcom - whether it can leave you howling for more - it is an abject failure.

This might be why The Detectorists' creator Mackenzie Crook initially pushed back against the "gentle" labelling when the show debuted in 2014. Isn't it the "edgy" comedies which clean up at award shows and win armies of devotees?

Except his passion project is in every aspect a massive success; so much so that, at this point, I'd suggest any headlines describing it as "a hidden treasure" are more to do with lazy sub-editors than anything else.

It's a series about two middle-aged mates - Lance and Andy - who go looking for ancient artefacts. Hence "hidden treasure". Geddit?

Yet the programme bagged a Bafta in its first year, was later named among Britain's best-ever sitcoms and has snagged a prime-time Boxing Day slot for its one-off special this evening.

And Crook who writes, directs and stars alongside Toby Jones - has achieved this acclaim by basically ignoring all the conventional wisdom about how to craft a hit.

This isn't a show of tightly-written half hours; it meanders and rambles and takes the scenic route to jokes.

Although given that much is shot on location in rural Suffolk there's certainly worse scenery to work with!

The Detectorists also entirely shies away from the set-piece moments that come to define sitcoms - be they falling chandeliers or cringe-inducing dance routines.

It's at its best when it's two middle-aged blokes, with a shared interest, sitting in a field ruminating on life, love, death and the previous evening's episode of University Challenge.

From the pastoral landscapes to the explicit references to popular quiz shows, it's fair to say that The Detectorists is also a firm rebuke to the idea that anything hoping to succeed in the Netflix-era needs to have one eye "on the international market."

In practice this usually means cutting out any cultural references Americans won't understand; one imagines that if this had started life on a streaming service the discovery of a 1983 Tizer ring pull would have duly been changed to something from a non-descript "soda can".

As something allowed to take root on the quiet backwater of BBC4, The Detectorists took precisely no notice of whether certain brands of carbonated beverage would be known outside the UK.

And yet it's found no shortage of fans elsewhere, The LA Times described the set-up as "almost Shakespearan", while Jones previously recalled being way-laid in New Orleans by two adoring viewers.

Only this month New Yorker Ben Lindbergh described Crook's creation as "just a well-written, well-acted, keenly observed show" and suggested the theme of trying to find one's place in life is universal.

In this regard The Detectorists perhaps has something in common with The Office - the show in which Crook came to prominence some 20 years ago.

But while the famous mockumentary came with a strong dose of cynicism - despite the rather sentimental romance at its heart - The Detectorists is unashamedly warm.

Perhaps that then would be a better word than gentle - warm. Gentle might imply bad things don't happen to fundamentally decent people. Or that a fundamentally decent person can't screw up, screw around or swear. Neither is true of this show but we're made to care about the consequences.

And increasingly you find you're invested in the successes as well. It turns out we want Lance and Andy to strike gold and that's down to the hobby at the heart of the show and the way it's represented. 

After three full series, a previous Christmas special and now this belated feature-length follow-up, it's apparent that metal detecting is both fundamental to the plot and utterly irrelevant. 

Fundamental insofar as it's an activity at the centre of every episode. Much happens - or often doesn't happen - at the parish hall meetings of the Danebury Metal Detecting Club (DMDC). A rivalry with fellow enthusiasts - who strangely resemble American folk rock duo Simon and Garfunkel - is commonly the source of the drama. And all too frequently our hobbyists have to remind people that detectors are the bleeping gadgets they carry - not the people who actually do the detecting.

And yet you start to realise that the particular pastime is inconsequential - it's what it represents to the characters that really matters.

If there's an inherent absurdity to spending hours combing a field and finding nothing but shredded drinks cans - colloquially known as canslaw - it doesn't mean it's not worth doing, or that it's somehow a uniquely strange way to pass the time.

Crook - a lover of aquariums and natural history and something of an amateur detectorist himself - knows when to probe the comedy potential of interests which become obsessions, without turning this enthusiasm into a subject of ridicule.

Perhaps a different writer at a different time would have been crueller, reasoning that most people don't spend their Sundays on the hunt for Anglo Saxon hoards so it is probably safe to send the whole thing up. 

This could have very easily ended up like a certain series - which I won't name here since I hate it - which rather heavily depended on ripping the shit out of certain interests, while expecting those who share those interests just to be grateful that anyone has made a show about them at all.

The Detectorists is not that show. It's inclusive and generous and I think that's why so many people are glad to see it back after a five year absence - albeit for what will almost certainly be a final encore.

Obviously you don't need to be a detectorist to get on board, even at this late stage; perhaps your own passion is the football or fishing, pub quizzing or bird spotting, pinhole cameras or claymation. 

Each of these hobbies has its own set of rituals and trivia, unspoken conventions and common misconceptions. To the outside these are often incomprehensible but for you they're the framework for where you escape after work, make friends and forget your worries. 

That's likely why The Detectorists strikes a chord with so many people and has almost effortlessly made the leap from sleeper hit to unequivocal success. There's something of a metal detector - sorry - detectorist in all of us.