Here's a question for you - is Felix Sanchez the best athlete in the world right now?
In some ways it's hard to compare athletes across different events, just as it is to compare boxers in different weight categories.
Sanchez's domination of his event is extraordinary
But if you go on who has won their world titles in Paris by the biggest margins, then Felix is the man.
That was the biggest winning margin in a world 400m hurdles final in history, bigger than the one the legendary Ed Moses had when he took gold in Helsinki in 1983.
Sanchez's dominance of his event is almost unique in the world of athletics. Ana Guevara has a brilliant record in the women's 400m, but she can be pushed.
There is no-one even close to Sanchez. He has now won 30 races on the bounce, stretching back to his first world title in Edmonton two years ago.
Darren Campbell is one of the few British athletes who can leave Paris with his head held high
There is also no-one improving out of the pack who you think might challenge him in the next few years.
Even if the rest do start running faster, Sanchez will be getting better too. He could run sub-47 seconds one day.
As for Chris Rawlinson, well, we're scratching around for British medal hopes and we shouldn't have pinned our hopes on him.
He has not shown on past form that he is capable of running his best in major world finals, and it was the same again on Friday night.
It's a very different game running in Grand Prix events to running in the big finals, and no-one apart from Sanchez has the consistency to do it.
With the exception of Steve Backley and Darren Campbell, Britain's hopes disappointed.
Steve will be happy to have made it through qualifying in difficult conditions and will now look for better in Sunday's final.
And no-one can criticise Campbell.
Coming into the 200m final I thought he might get fourth, but a distant fourth - yet there he was again, absolutely running his best when all else were failing to do so.
He is one of the few British athletes who can leave these championships with his head held high.
Chris Tomlinson in the long jump was unlucky not to get through to the final eight, and his second jump - a marginal foul - certainly looked long.
Still, you wonder if he wouldn't have been better off getting a half-decent jump in first and then going for the big one later, rather than going for broke from the word go.