Hello and welcome to more or less on the BBC World Service. We are weekly guide to

the numbers all around us and the news and in life, and I'm Tim Halford.

Ten years ago, Yusain Bolt broke the 100 metres world record at the World Championships

in Berlin. He ran that 100 metres in 9.58 seconds. No one has got close to beating that

time. This summer, at the World's Swimming Championships, the UK's Adam Petey broke

his own world record over the 100 metre breaststroke. He became the first swimmer to go under 57

seconds. In fact, no one else has gone under 58 seconds. Two extraordinary performances.

But which is more extraordinary. Yes, in today's programme, we're going to ask who would

win in a race between Adam Petey and Yusain Bolt, not on the track, not in the pool, but

in the world of statistics. Our guide is Professor Daniel Ticata, a Brazilian statistician

and swimming fan. The question might seem impossible to answer, but as Professor Ticata explained,

you get to an answer by comparing Petey and Bolt, not to each other, but to their rivals.

He started by comparing Adam Petey to other swimmers. This is a phenomenal record. He is

1.4 seconds faster than the second performer of all time in the event. That's a 2 metre

gap in a sport often decided by a fingertip. If you look at other world records, that's

very unusual. In the 100 freestyle, for example, Brazilian

Sessar Cielo is the world record holder. With the time of 46.91, which is just 300s of

a second faster than the second performer of all time.

300s of a second is 3 centimetres ahead of the next fastest swimmer. But that's just one

comparison between the best and second best. Ticata has used clever statistics to do a more

sophisticated analysis. I'm comparing the world record with the second fastest performer

of all time in this event. But actually, I can go deeper. I can compare it with a population

...