Of all the dubious statistics thrown around in relation to the London Olympics, the claim that there are '47 tube journeys in central London that can easily be walked' is surely one of the most misleading. I suspect it is based on the relative proximity of one station to an adjacent one. Embankment is walking distance from Temple. Charing Cross is a stone's throw from Leicester Square.
But what exactly is a 'tube journey'?
As I've understood it - and I'm only going on three decades' experience of using the network - it is a journey that takes you from any one place with a tube station to another. My journey from Leicester Square might take me to Charing Cross, but it might also lead me up the line to Camden Town or down south to Morden. In fact, from any one tube station - thanks to the wonders of interconnections - there are dozens, maybe hundreds, of options available to me.
Now, I don't claim to have a PhD in mathematics, but the number of potential tube journeys is astronomical, isn't it? You would need equations and a head bigger than Sebastian Coe's to work out all the permutations. Tens of thousands? Hundreds of thousands?
Of course, it's always good to know we can easily walk 47 of them. But I would be entering the 800m Stupid Race if I believed this figure had any significance.