My old event, the men's 400m, is going to be like no other we've seen for many years in the Olympic Games. The fact that LaShawn Merritt failed to get round in his first-round heat yesterday, pulling up injured before halfway, has completely changed the dynamics.
Merritt was the defending champion. He won in Beijing four years ago and two other Americans, Jeremy Wariner and David Neville, took silver and bronze. Historically, in the men's 400m, you've had three great Americans and they usually win the medals.
Now, with Merritt out, there are no Americans who are going to factor in London. Suddenly, it's a very different event.
It's been won by Americans at every Games since 1984 – Alonzo Babers that year in Los Angeles, Steve Lewis in Seoul in 1988, Quincy Watts in Barcelona in 1992, Michael Johnson in Atlanta in 1996 and in Sydney in 2000, Jeremy Wariner in Athens in 2004, Merritt in Beijing in 2008.
You've now got the widest open 400m ever at an Olympics. You've also got Great Britain in with a big chance of a medal in the 4 x 400m relay. Without Merritt, the Americans don't have much of a team. Our chances of a medal now are huge.
That's significant. So was Jonathan Borlée of Belgium winning his heat in 44.43sec. To run that fast in the first round of an Olympic Games is madness. It's totally unnecessary.
Unless Borlée is in the best shape of his life and wins the Olympic Games, he may well live to regret that. You don't need to run that fast to qualify in the first round of an Olympic Games. That will take stuff out of him.
Kirani James, the 19-year-old from Grenada who won the world title ahead of Merritt last year, showed how to do it, jogging round in 45.23sec. In the first round, you get it out of the way without doing too much.
The semi-final should be quick – because obviously it's a very fast track – so if Borlée really is in great shape he'll probably threaten the European record, which is fantastic.
It's about time that it went. It's stood at 44.33sec to Thomas Schonlebe of East Germany since 1987. A few of us have come close to it. It's time someone broke it.
It would be good if it was Jonathan Borlée. The Borlée twins – Jonathan and his fellow 400m runner Kevin – are a lovely story. They're big, big news in Belgium.
It would be nice to see Schonlebe's record go. But don't assume just because someone runs well in the first round that they can do it in the semi-final.
As I said, I think the event is wide open now. It's good. It's the changing of the guard.
James is the favourite, but we'll know more after the semi-finals. First rounds don't really tell you much.
The good news is all the Brits have got through – Martyn Rooney, Nigel Levine and Conrad Williams. With Merritt pulling out, they've got a much better chance of making it to an Olympic final, which has to be the goal. I'm sure there's a chance that one of them, probably Rooney, will make the final.
It's pleasing to see Oscar Pistorius making the semi-finals. It's an amazing achievement.
We should celebrate that he's out there doing it. The world is watching a man with no legs compete against people with legs. It's truly inspirational and it's historic.
Let's all put all of the rights and wrongs of Oscar competing to one side for now. He's here at the Olympic Games. Let's celebrate an incredible human being, which is what he is.
Roger Black will be writing for 'The Independent', 'The Independent on Sunday' and the 'Evening Standard' during the Games, and is an ambassador for Scottish Widows, the official pensions and investments provider for the London 2012 Olympic Games. As part of the Lloyds Banking Group, Scottish Widows is proud to be an Official Provider of the London 2012 Olympic and Paralympic Games