So there I was sitting on my sofa eating a bag of Onion Rings watching the 4x100metre heats and I didn't expect to watch carnage.

Neither US squad made it to the final and both times it was the change between the top bend runner and the home straight runner than went awry.

For the women it was a problem as the incoming runner slapped the baton into the outgoing runners hand and let go before the outgoing runner grasped it. For the men it again the incoming runners fault. Tyson Gay put his arm back but the incoming runner just couldn't find it and out when the American's.

So it all set up for a great chance for us to defend our title, right? Wrong. Team GBR were DQ'd for their final change in the heat. It was the fault of Craig Pickering who went off far too early and was out of the changeover box before Marlon Devonish could catch up and pass him the baton.

It was quite a few minutes of athletics. It was really a case of 'how not to run a relay' race from several squads. At least the British woman made it to the final!