Can you help comedian Dave Gorman solve this estimating problem?

Dave Gorman is one of my favourite comedians.  He's clever, funny, a good bit twisted, but not rude.  He makes powerpoints.  Funny ones.

Anyway, Dave has a problem, according to his facebook page.  It's a forecasting / estimating problem, with a few constraints. I can't think of a solution.  Can you?

Just so you know what you're reading, we start with (1) a comment from an annoyed fan, the rest (2) is Dave's rather thoughtful response.  

  1. [Annoyed Fan] Sad that we never got to see you in London, 2 hours in car/tube, queued for 2 hours only to get close to the door and told it was full [frown emoticon] Us and the other 150 disappointed people behind us had to go home frown emoticon gutted

  2. [Dave Gorman] I'm sorry to hear that Abby. I believe it was actually between 70 or 80 people that didn't get in. That's more people than normal - although a similar number to last month's recording.

    Here's the thing: tickets for recordings have to be free. (I don't know why that's the case, but it is. They *have* to be.)

    Because they're free a *lot* of people request them and then don't use them. It can be for all sorts of reasons. Some people just forget. Some people discover there's football on the telly. Sometimes it's a sunny day and you're in a beer garden and someone gets another round in and... well, what the hell, they were free anyway.

    The %age of people who turn up can vary enormously. This is our third series. Last series there was at least one of our four recordings where nobody got turned away and we could have got another couple of people in.

    They'd issued the same number of tickets for that recording as they did for the most recent recording. The attendance rate can be anything from 30% to 80%. With that amount of variation, it's almost impossible to guess the right numbers. Go too low and you can end up with a half full venue. Go too high and you can end up making people unhappy when they don't get in. As far as I know, they use the figures from the previous series to make their estimates. I don't know how else they could do it. How would you do it differently?

    If the same %age of people had turned up as normal, there wouldn't have been an issue. You can't really blame them for expecting it to be the same as normal. That's what anyone would expect. After all, that's what "normal" is. 

    Everyone who is turned away should be offered a guaranteed seat at a future recording. If you weren't, get in touch with them.

    All in all, it's a nigh on impossible task to get right. I'd much rather they were able to sell tickets for these sort of things. Not because of the revenue but because the drop out rate would be tiny and the whole thing would be much easier to manage. From my point of view, the problem is caused by the number of people who request tickets and don't use them. For what it's worth, two of the people who complained loudest about not getting in at the last recording, were people who had requested tickets for series two and then not turned up! They're the cause of the problem. They're the reason we can't issue 200 tickets for 200 seats! 

    Nobody enjoys turning folks away. Nobody wants disappointed punters. But nobody can risk empty seats either. That's why the risks of not getting in are always explained. Ironically... one of the reasons some people decide not to come is that they assess the risk and decide it's not worth the journey. So the more you explain the problem to people, the bigger the problem gets!

    I hope you can avail yourself of the guaranteed seat at a future show. If so, I'll see you there. But in any case, I'm sorry the day didn't pan out as you hoped. It's not for want of trying on our part and despite what some people said to us on the night - we didn't "obviously distribute way too many tickets". We distributed numbers of tickets that on other nights wouldn't have filled the venue!