You see a lot of close finishes in the sprints.
100m, 200m, the hurdles,
it's in the nature of sprinting
that victory is won by tiny margins.
Fans love it.
Kids these days, always on their phones.
Hm, what?
For sprinters, microseconds are their business, their currency.
For them, one tenth of a second
in the 100m final is an eternity.
It's all a matter of proportion.
You don't see many dead-heats in the marathon.
But there was one long-distance race, lasting two hours,
which really did come down to the wire.
As you'll see, we're talking close, really close.
The triathlon has quickly become one of the iconic events
of the summer Games following its introduction in 2000.
It comes in three sections. The swimming. The cycling.
And the run.
To spice it up, it has awkward little transition sections
where so often the race is won or lost.
It's an event virtually designed to smash the field,
to scatter the competitors
into one thin line of athletic torment.
The previous Olympic Women's event was won
by well over a minute.
No photo required.
The Women's Triathlon at London 2012 was different.
Here are the two athletes to look out for.
Lisa Norden of Sweden
and Nicola Spirig of Switzerland.
You can barely see them in the swimming section
because neither of them counts it as their best discipline.
There are some very good swimmers in here,
as we say, look out for
Great Britain's Lucy Hall, who's wearing 8.
She will more than likely take Vicky Holland with her.
Lucy Hall of Great Britain emerged from the water
with a handsome lead.
Spoiler alert - Hall would finish 33rd.
It's a cruel sport.
The split times tell us that Norden and Spirig
complete the swimming events in exactly the same time.
The Swiss Spirig considers the cycling her top event.
She's awesome on the bike,
quickly making up time lost on the swim.
But Norden is having a good race,
she feels strong, matching Spirig
in her strongest discipline.
Well, here they come back towards transition.
Here comes Nicola Spirig.
It comes down to the run.
The final 10K of an Olympic triathlon is a thing of wonder,
athletes pushing themselves to the limit,
with unbelievable reserves of energy and determination.
Spirig has both,
and puts herself in prime position for the final section.
She is flying.
And looking at some of the runners in that field,
the likes of Nicola Spirig,
this could literally come down
to a sprint finish for the three medals.
She holds off the Australian, Erin Densham.
But, try as she might,
she cannot not shake off her Swedish rival.
Lisa Norden - is this going to be her day?
Here they come. It is a sprint finish.
It's all come down to this.
Two hours of racing,
Nicola Spirig and Lisa Norden, it would appear.
The Australian has gone.
Spirig, look...look for the Norwegian,
the big, long strides of hers,
and she's eating into the Swiss.
Look at this, nothing between them as they go into the tape.
Dead heat.
Densham bronze, while Spirig and Norden
have to wait for the judges
to examine photographic evidence.
Even now it's hard to judge.
Eventually, a decision is made,
the same time for Spirig and Norden.
The same time to within one-hundredth of a second
but Nicola Spirig wins, by a whisker.
It hasn't sunk in yet, it's...
I don't think I really realise that
I'm Olympic Champion now
but it's amazing, it's just amazing.
It's been a lot of ups and downs, and this is amazing.
I had so many injuries leading up to this and I never thought
I'd get it together and running in the last ten laps, I felt
amazing and I realised I could probably get a medal
and actually up until the last couple of metres...
It's really amazing.
The photo suggests victory by the tiniest of margins,
maybe two centimetres, to be generous.
That's over a race that's 51.5 million centimetres long.
You've already worked that out as a percentage, right?
So, if, say, this was a 100m sprint
it's the equivalent of winning by a margin so slim
it's almost beyond human detection.
38.8 micrometres, to be precise.
The diameter of a typical human hair is about 50 micrometres,
less than a hair's breadth!
You could watch 1,000 triathlons,
1,000 races and never see a finish as close as that.