It was the late 1950s when the science-fiction writer Theodore Sturgeon was accosted by an inebriate at a party who asked him what he did for a living. When Ted told him, the drunk said, "Why is 95 per cent of sci-fi crap?" "That's easy," replied Sturgeon. "Ninety-five per cent of everything is crap. It's the five per cent that's good, or even great, that makes the rest bearable - necessary, even."
The 95 per cent crap theorem is known as Sturgeon's Law, and it's oh-so-easy (and entertaining) to poke fun at the 95 per cent of TV and radio that is absolutely putrid pants with matching grubby grey bra - everything from Strictly Dance
Fever and ITV's entire Sunday- evening schedule (Heartbeat, The Royle, Wild at Heart, Where the Heart is... TV for incontinent Alzheimer sufferers) to the endless slew of property porn on all four channels.
Then there's the ghastly overload of grisly exploitative makeover shows, from the almost watchable, such as Trinnie and Susannah's efforts, to the chavalanche of appalling rubbish such as Ten Years Younger and Bride and Grooming and You Are What You Eat, not to mention the endless variants on various non-terrestrial channels.
What is particularly dispiriting about television at the moment is the way that even stuff that ought to be part of the magical five per cent has gone crappy. The news, for instance. The half-hour local news bulletins around the country are, of course, a joke beyond parody - especially on the BBC, where they're scheduled to follow the main news, and, in large conurbations, simply tend to repeat it. There really isn't 30 minutes of news worth hearing about in the whole world most days, so forcing local news operations with delusions of adequacy to fill half an hour a day is a cruel punishment for both the hacks chasing stories about a cat up a tree in Cleethorpes, and the viewers wasting valuable brain cells watching it while waiting for Emmerdale to start.
But our national television news is also in a pathetic state. There is way too much speculation from correspondents, masquerading as informed journalism, and the laughable overuse of outside broadcasts when a 10-second update from the presenter would suffice. They have to pad out their piss-poor reports so much to fill their 30-minute slots - which is also why the running order of most TV news bulletins rarely changes throughout the day, as they force-feed us the drip, drip, drip of government press releases and comment pieces ripped off from the previous day's newspapers.
When was the last time any television news operation broke a big story? When do they ever do any proactive, campaigning journalism (apart from exposing some poor corner-shop owner for flogging knives/ cigarettes/glue/booze to an underage kid)?
Channel 4 News, with its smugnuts - self-satisfied and borderline creepy crew of "character" presenters - is particularly puke-inducing. So, plenty of room for improvement there - we could start by going back to the 10-minute- maximum news bulletin of the 1970s and early 1980s, with, say, a five-minute local round-up. After all, if you want news, there's the radio and the rolling TV services, and on the rare occasions that a story warrants an extended bulletin - or even ongoing coverage - they could just clear the schedules.
Then there's the way that television in this country completely and cravenly fails to represent the reality of British society in either its dramas or its current affairs. Working- class and lower middle-class culture and values are either patronised or openly derided in everything from EastEnders (scribed exclusively by minor- public-school pupils who probably think that Walford is a real place and that Phil Mitchell could be a hard man) to the increasingly desperate comedy output of British TV.
More disturbing, though, is the way the boob tube virtually ignores the multiracial and multicultural nature of the UK. I was asked recently to judge the TV section of the Race in the Media Awards (the results are announced on Wednesday). It was a fascinating and uplifting experience as there are some excellent documentaries and education shows covering everything from the US government's criminal actions after the devastation of New Orleans to the plight of Polish immigrant workers.
I watched over 50 possible contenders - about four of which were broadcast in prime time on any of the terrestrial channels. Because that's the magic time reserved for soaps, or being shown round other people's houses, or seeing fat lazy Northern women having fat sucked from their bellies so that they can renew their marriage vows.
Oh, and don't expect British dramas to inform us about these issues because black or Asian or immigrant characters are always stereotypes - neutered or emasculated stereotypes on a patronising par with the unpleasant xenophobia of the 1970s and 1980s. And we're meant to know better now.
I caught an episode of the American show House last week, and it featured one of the performances of the year - a rounded and believable and moving portrayal of a flawed individual in a desperate situation. One of House's students had contracted a painful and probably fatal disease. He's played by Omar Epps, who is brilliant and who happens to be black. I couldn't think of one single British drama that has given that kind of role to a black or Asian or Chinese actor - a role in which racial origin is irrelevant and the writers aren't afraid to make the character unpleasant and selfish. Human, in fact.
That brings us, finally, to the quality five per cent of home-grown gems. Life on Mars, of course, and ITV's recent excellent run of one-off two-part dramas (The Best Man, The Kindness of Strangers, Ghost Boat). Then there's Harry Hill's TV Burp (which should be on 35 weeks of the year), and Ant & Dec's Saturday Night Takeaway (which should be on every week of the year, apart from when they're presenting I'm a Celebrity, Get Me Out of Here!)
And that - apart from the odd Dispatches and wildlife documentary series and drama co-productions such as Rome - is about that, with an honourable mention for event telly such as Celebrity X Factor and the closing fortnight of Big Brother, ie unmissable but deeply forgettable.
Sadly, most of the decent stuff on our screens is imported: CSI and House and 24 and Nip/Tuck and Scrubs and Everwood and Firefly and The 4400 (a classic science-fiction series just out on DVD that didn't even make it on to terrestrial TV here).
Oh, and that mention of sci-fi reminds me. Sturgeon's Law - the one about 95 per cent of everything being crap - you've probably never heard of him. That's because his novels and stories are pretty poor. Ironically, he's not part of the five per cent that makes the rest of the rubbish bearable.
Paul Ross is a television presenter and producer and hosts the weekend breakfast show on LBC 97.3FM, 7am-9am Saturday and SundayReuse content