For a long time, Chance In A Million was set to become another in a long line of comedies that are fondly remembered by those who watched it, but not deemed viable enough for a commercial release. Fervent fans traded episodes online and nostalgic nattering persisted on forums. Finally, in the now distant-seeming days of 2010, their prayers were answered when Revelation Films released all three series. But the question was, after such anticipation; would the series stand up? The answer, thankfully, is a resounding yes.

Simon Callow stars as the ironically named Tom Chance, a man who is, in his own words, "personally, persistently plagued by coincidence", alongside Brenda Blethyn as his girlfriend, secretly rambunctious librarian Allison. First aired in 1984, the 'unlucky man' conceit was of course nothing new in sitcoms even then.

In 1954 Galton & Simpson created the archetypal grump in Hancock's Half Hour. Beginning on radio and transferring to television two years later, Tony Hancock wore a haughty hangdog expression as each episode saw him battle against his unfair lot in life - albeit largely of his own, somewhat pompous making. The sixties and seventies welcomed the likes of Dad's Army, George & Mildred, Some Mothers Do 'Ave 'Em and, in 1981, Ronnie Corbett's most well-known sitcom, Sorry!. Harried husbands and mollycoddled men had become a common sitcom lead, but this was where Chance's writers, Andrew Norriss and Richard Fegen, tried to break the mould. To some extent alike Frank Spencer before him, Tom is unlucky in everything except love; a decision that immediately freed up the plots from any notion of 'will they/won't they' and allowed them to concentrate solely on structuring each story.

Norriss and Fegen take the concept of Chekov's Gun (if a gun is introduced in Act One then it must be fired by Act Three) but instead of using it for one gag, they integrate it into the nexus of the narrative, each situation exacerbating the next. Scripts were actually written backwards, in that they thought of the most outlandish gag possible and then worked back through the plot to put the pieces in place to facilitate it.

The circumstances in which Tom and Allison meet set out the stall for the series in the opening episode, Plumstones. Allison is waiting for her cousin, whom she has never met before, Tom Chesney. Tom is waiting for his blind date who happens to be called Allison. Meeting in the bar, each is mistaken for the respective other half and they strike up a conversation. Tom opens the proceedings by warning Allison of his unfortunate affliction, which is where the episode's title comes into play. Listening to Tom's spiel in which he outlines his extraordinary experiences, Allison concludes that "in life's great crumble, as it were, it's always you who finds the plumstone".

As their day continues the pair help a woman who is locked out of her car, attract the ire of an insolent waiter in a French restaurant (who it turns out was the spurned lover of the aforementioned woman) and subsequently get into a food fight, culminating with a policeman discovering Tom and Alison in their underwear trying to break into Tom's house (his keys lost and their clothes having been ruined in said food fight).

Each episode followed this farcical formula, allowing Norriss and Fegen to come up with ideas and visual images seldom seen in sitcom before. Future episodes include a parachutist dropping into their garden, Tom stumbling upon a political scandal and, in the final episode, a series of events leading to Tom and Allison's entire wedding party being stuck in a sewer.

There is a tremendous amount of warmth in Chance In A Million, largely due to the central performances delivered by Callow and Blethyn. They share a magnetic chemistry: Callow's strong, stoic demeanour the perfect counterpoint to Blethyn's timid introvert. As time goes on, Allison is revealed to have intense carnal cravings to which Tom is utterly oblivious. But there is a delightful innocence to the proceedings, for if Tom were upset by the situations in which he finds himself, the show would become something entirely different. It is his optimistic outlook upon life juxtaposed with the insanity around him that makes it work. Equally, Allison - while slightly more perturbed by the predicaments - struggles through with him and it is this indomitable spirit that brings them closer together.

Something particularly unique to Chance In A Million is the dialogue. Norriss and Fegen imbue Tom with very measured, staccato speech. For example, describing an unfortunate bus journey in the first episode: "Seat in front covered in four letter words, married couple in row behind having blazing row, child across gangway puked into the aisle. Got off. Bus going in wrong direction". Closely resembling Dickens's The Pickwick Papers, the intention was to make Tom an old-fashioned English eccentric. Another quirk was his propensity to down a pint of lager mid-sentence (achieved, according to the DVD commentaries, with a trick glass containing only a fraction of liquid). Every sitcom tries to do something that makes it stand out, and these two character quirks helped to fix Chance In A Million in the collective consciousness.

Several sitcom stalwarts appear in supporting roles throughout the series. Bill Pertwee, of Dad's Army fame, played the ever patient Sergeant Gough, who is so used to Tom's misfortune that in the debut episode he orders his officers to never arrest Tom no matter how suspicious the circumstances; and in Series 2, Graham Crowden, who went on to co-star with Stephanie Cole in Waiting For God, played a vicar who tries to convince Allison not to marry Tom.

In the years since Chance In A Million was made, both Callow and Blethyn have blossomed into national treasures, while Norriss and Fegen continued to write sitcoms. These included the little seen Richard Griffiths and Benjamin Whitrow vehicle Ffizz, another starring role for Brenda Blethyn in The Labours Of Erica; and their greatest success, The Brittas Empire. Brittas contained many familiar elements the writers honed on Chance: eccentric characters, escalating farce and improbable coincidences. Likewise, the respective central characters - Tom Chance and Gordon Brittas - share several traits. They are both completely oblivious to the underlying needs of their partners and both are privy to preposterous sequences of events ending in calamity, all whilst remaining defiantly positive. What differentiates Chance from Brittas is his affability and genuine eagerness to help others. Not that Brittas was mean spirited, but his lack of self-awareness combined with his rigidness with regard to the rules was the main source of conflict in his world. In many ways Tom is the opposite, authoritative in his demeanour but not actually in a position of authority. His self-awareness is also evident right from the start when he warns Allison about his life of calamity and coincidence.

Although a reunion episode was mooted by Callow a few years ago, the idea only got as far as Norriss and Fegen brainstorming ideas and the project never got off the ground. As it is, Chance In A Million's intricately written scripts ensure that it stands up remarkably well to repeated viewings. Callow writes in the sleeve notes of the DVD that Chance In A Million was "one of the most enjoyable jobs of my career, a show which everyone who saw at the time (and there were a lot of them) has remembered with deep affection".

Blethyn also has fond memories of the series, writing in her autobiography Mixed Fancies "it was such fun making Chance In A Million with Simon. The combination of his intellect, sense of humour and booming laugh was intoxicating". I'll leave the final word to Andrew Norriss himself, who said that "it was all a very long time ago - how lovely that anyone remembers it still!"