Only Connect: Victoria Coren Mitchell's fiendishly difficult cult quiz overtakes BBC1 in ratings

The quiz show in which teams compete to find connections between seemingly unrelated clues has quietly become a mainstream hit

Host Victoria Coren presenting Only Connect, the quiz show in which teams compete to find connections between seemingly unrelated clues (BBC)

What is the link between these numbers? 285,000, 684,000, 1.1m, 2.9m. The answer is they are soaring viewers figures for Only Connect, the toughest quiz on television, which began as a BBC4 obscurity and has now overtaken BBC1 in the ratings.

Presented by Victoria Coren Mitchell, the quiz show in which teams compete to find connections between seemingly unrelated clues, has quietly become a mainstream hit.

Launched on BBC4 in 2008, Only Connect, which invites two teams to choose questions hidden behind Egyptian hieroglyphs and solve a wall containing groups of connected items, now delights and baffles an audience of nearly 3 million viewers. Celebrity contestants, including David Baddiel, are queuing up to test their wits on special editions.

Transferred to BBC2 last year, reflecting its cult popularity, the Monday night edition broadcast this week enjoyed a peak audience some 200,000 viewers ahead of BBC1.

What is the secret behind the success of the programme, which might typically ask “what connects (1) He’s my brother (2) Well, nobody’s perfect (3) Mein Fuhrer, I can walk (4) It was Beauty killed the Beast?” (answer – they are all last lines in movies.)

“The BBC has consistently said to us ‘Don’t make it any easier’. Our USP is to be the toughest, brainiest quiz on television and we like to think it works because of that,” said Chris Stuart, executive producer.

Stuart took the concept to the BBC after tweaking an original idea for a quiz called “Four Share” about numerical sequences. “That was a bit dull, I thought it would work better if it was about connections.”

Although the questions might seem impenetrable to some - the missing vowels round once asked teams to find the fictional suicide contained with the formulation C CS N - viewers enjoy seeing the egghead contestants struggling to come up with an answer against the clock.

“Viewers say if they can answer one or two questions right, it makes their week,” Stuart said. “If they can’t answer the questions themselves, they enjoy watching those who can. But the questions are often playful. The answers have to be gettable.”

Although, Only Connect has spawned an app, it is perhaps too testing for international viewers. “British audiences like quizzes where they don’t know the answers. Formats like Only Connect and University Challenge (with which it forms a BBC2 quizzing power-hour) don’t travel very well,” Stuart said.

Alan Tyler, BBC Executive Editor, Entertainment Commissioning, said: “There’s something quintessentially British about Only Connect. It’s a tough application process to get selected. Traditionally these quizzes appeal to middle-aged men so we would like to see more women apply.”

Mrs Coren Mitchell, who is often the final arbiter of whether a fiendishly difficult question should be allowed, since she has to explain the answer, is a crucial element of the programme’s appeal. “The series celebrates knowledge. Victoria gave it personality, and a knowing wink so people don’t take it too seriously,” Tyler said.

Now in its 11th series, the only question Only Connect’s producers cannot answer is how long can they keep dreaming up chin-scratching clues. “The thought process behind each episode is like preparing a sitcom script,” said Stuart. “It gets harder to generate new questions. We’ve pulled down all of the low-hanging fruit. But we’re not running out of questions just yet.”

Its ratings surge might make Only Connect the next candidate to be poached by BBC1, following its raid for The Great British Bake Off. However Mr Tyler said the quiz would be staying put on BBC2.

So the challenge will remain just as intense for the Only Connect teams – even if they do work out that adding the missing vowels to C CS N produces Madama Butterfly’s Cio-cio San.

Kim Shillinglaw, Controller BBC Two and BBC Four, said: “I’ve been so pleased to see Only Connect go from strength to strength and establish itself as a much-loved part of the BBC Two schedule. With the fantastic Victoria Coren at the helm – a wonderful presenter who you want to spend time with - and fiendishly difficult questions, Only Connect brings viewers just the kind of grown up entertainment that I want to see on BBC Two.”