Scientists have come up with what they claim is the formula for determining a sitcom’s success.

The spurious equation, involving such unscientific elements as the ‘recognisability’ of the man character and a factor for their delusions of  grandeur.

The formula conveniently makes Only Fools And Horses the funniest sitcom of all time, followed by The Office and Father Ted; while Johnny Vaughan’s Orrible came bottom.

Scientists-cum-comics Dr Helen Pilcher and Timandra Harkness were hired by repeats channel UKTV Gold to come up with the formula for success.

It is (F(RD + V) + S)/ A

Harkness said yesterday: "If you pushed us, we would have to admit to an element of subjectivity but we did go to some effort to find a formula that worked whatever you applied it to.

One hypothesis we had to abandon was a score for sexually attractive characters. It just mean everything with Felicity Kendal scored millions.

"Unfortunately, we didn't have time to test it on offbeat comedies like Black Books, but we would like to. It would also be interesting to apply it to a script for a comedy that has not been made yet."

Pilcher added: "There are long-standing golden rules for sitcom,  but our findings bring them down to this single equation.”

R is the  recognisability of the main character, D is their delusions of grandeur, V is the verbal wit of the script, F is the pratfall factor, S is the difference in social status between the highest- and lowest-ranking characters and A is the success of any scheme

The top shows were

1. Only Fools and Horses
2. The Office
3. Father Ted
4. FawltyTowers
5. Blackadder

And the worst were

1.  'Orrible
2. Babes In The Wood
3. Sam's Game
4. According To Bex
5. Eyes Down