Parsons points out that "pre-knowledge" of the subjects is an option that more confident guests could decline, if they wished to do so.
"We discovered, right at the beginning, that if the subject was completely unseen, the guests were umming and erring within a few seconds," he says. Such old hands as Clement Freud don't mind having a subject sprung on them; Paul Merton, by contrast, likes to know what's coming up, so he can have one of his stratospheric riffs all ready to go. In Parsons' view, you can't beat a rehearsal for making a spontaneous monologue go with a swing.
Well, honestly. We're still reeling from the news, last year, that the droll exchanges between guests on Have I Got News For You? are all rehearsed for months before being uttered. We've only just dried our tears after learning that guests on the Channel 4 quiz show Countdown are prompted towards the right combination of letters by a studio hand whispering answers to them through an earpiece.
How many more ghastly revelations will we have to endure? Must we envisage the prospect of Jeremy Paxman circulating the BBC2 green room, muttering "Who invented hieroglyphics? Rameses II. Don't forget. And which opera, first performed at the Viennese Statsoper in 1846...?" (But I think we can probably discount any suggestion of answer-rigging on University Challenge, given the panellists' startling level of ignorance about, say, the date of the Abdication.)
Since it seems to be the fashion to blow the whistle on rule-bending in radio shows, here goes: I was told some of the questions when I appeared on Nigel Rees's Quote Unquote programme a few years ago. As we sat in the hospitality room, glumly flooring hock and peanuts, the show's producer appeared by my side.
"Shall we just run through one or two of them now?" she asked brightly. "Where does the expression `Nice one, Cyril' come from?"
I said I thought it was a Hovis commercial, or possibly a football chant involving Cyril Knowles of Tottenham.
"OK. Who said `I have nothing to declare but my genius'? Of course, it was Oscar Wilde. And which French politician memorably declared in 1916: `Ils ne passeront pas'?"
"Wait a minute," I said. "Don't tell me the answers. If I don't know them, I can always have a reasonable stab."
"Oh, all right," she said mildly. "But some people do get self-conscious about the gaps in their learning and like to have a bit of help. I mean, we don't want any awkward silences, do we?"
And you know what? She was right. Quote Unquote passed in a blur of amuse- ment. Everyone sounded knowledgeable, occasionally forgetful, breezily well-read but modest with it. Every time a contestant said, "I'm guessing here, but is it by any chance...?", you knew for sure that they'd been given the answer beforehand, along with the peanuts.
Some of us had taken advantage of the producer's crib, others had politely disdained. But the point was the show, and the fact that it sounded relaxed, well-balanced and civilised. Whether they really recalled the provenance of the quotations hardly mattered. The audience wanted them to know the answers and be droll about them; nothing more.
Letting guests see the answers is basic showbiz management. It may involve a slight con trick, a tacit white lie, but it's a deception that is no more heinous than the unseen mattresses that break the fall of the plummeting heroine at the end of Tosca.
Purity and probity aren't everything. They can even be counter-productive. I know this from going on a literary quiz series last summer. It was called The Write Stuff, written and presented by the TV critic James Walton and featuring the novelist Sebastian Faulks and myself as team captains. We were allowed one woman writer guest each week. We were not, needless to say, shown any questions beforehand, though we were alerted in advance as to who would be the featured "Author of the Week": Dickens, Chandler, Austen, DH Lawrence...
It was lip-biting, buzzer-trembling stuff. My fingernails clawed and scissored the Royal Society of Literature's damask tablecloth. Sebastian Faulks, urbane as a Venetian doge, flicked imaginary specks of dust off his flannels and answered everything in a growly, I-think-you'll-find- it's-Ossian baritone. I concentrated harder. It became something of a school-swot battle. Interrupted questions and instant answers flew around like tennis balls.
"In what year was the first novel by EM- " Bzzz. "1905."
"Which French novelist once played in g-" Rrring. "Albert Camus."
Which single eight-syllable word forms the first li-" Bzzz. "Polyphiloprogenitive."
The reviews came out. "Faulks and Walsh," sniffed one critic, "were as competitive as spermatozoa. They wouldn't let their women guests have a look-in". Ye gods, I thought. In a quiz? Should we have said, "I'll have to think about that one. While I'm busy with my pipe, Hermione, perhaps you'd care to have a go?"
Would listeners have been happier with a slower, carefully stage-managed exchange of queries and responses, rather than a blizzard of raw knowledge? You bet they would. Whatever the hidden wiring, whatever sleight of hand it takes to make a broadcast show more comfortable for the listeners, I don't see any great harm in it. It makes for a smoother, funnier, more "civilised" half-hour. I just wouldn't want to take part, that's all.