Younger readers may not recall the popular singing group The Who who worked as the backing band for the eminent time traveller Doctor Who. “I’m a substitute for another guy,” sang Roger Daltry, the shortish lead vocalist. “I look pretty tall but my heels are high.” This was the theme time to the much under-rated job of understudy.

To some performers, no doubt, being an understudy is a good gig. As I have discovered recently as the ‘reserve’ for several episodes of Celebrity Mastermind, getting paid for doing nothing is very agreeable indeed. I did not have to turn up to the studio to watch the recording, merely select a specialist subject and be on the end of a phone for the evening – although I was disappointed when I couldn’t have my favourite specialist subject ‘the life and times of Magnus Magnusson’. In the event, none of the contestants fell ill or chickened out and I felt great to have been remunerated for being .

This, however, is not the same as being a proper actorly understudy. For that you have to learn the lines, rehearse with the other actors and turn up for the show every night even if you do spent it sitting in the smallest dressing room doing the crossword.

Hanging over you is the prospect – or, if you’re understudying Martine McCutcheon, the near certainty – of going on and trying to remember it all in public, a much harder task than sitting in a chair and failing to answer general knowledge questions.

In the mid-eighties I was asked to audition to be understudy to Frankie Howerd in a productions of A Funny Thing Happened On the Way to the Forum and declined before I had heard the end of the title. Even if I had summoned up a good performance, the evening would surely be as disappointing as Chris Moyles’ TV career. Actually on reflection Moyles’ career was only disappointing to him; to the rest of us it was great since it ensured he couldn’t be on TV again for several years.

Hello, this is Arthur Smith here. The column up until now has been written by my journalistic understudy, Brian. I don’t think he was doing very well with his dull thoughts on understudying and you certainly won’t be hearing from him again.

I have fired him to finish the while myself because after all these years I have finally got a tip on how to make yourself a better comedian. It comes via a conversation I had with lovable redneck comic Greg Proops. As an American who works in Britain he is always asked to compare comedy on either side of the Atlantic. There is a whole lot of standard guff on this but I’d never heard Greg’s take on it. He said that American comics give the audience less time to laugh before moving on to the next line ie their tempo is slightly higher. Listening to Greg I observe the truth of his remark. He never ‘steps’ on a laugh but he leaves the audience gasping as he moves relentlessly through the material. This heightens the excitement and makes it easier to create a crescendo. It lends the material an urgency that a more relaxed delivery might not.

So if you want to stop being understudious do your gags 4% quicker and get 15% more laughs. Good afternoon.