He's back, he's upset, and he's really fast

DAEGU, South Korea - Sprint superstar Usain Bolt looks certain to retain his world 200m crown and banish the demons of his 100m misery, but his rivals will gain confidence from the knowledge he is human after all.

The Jamaican has a shot at redemption on the track in South Korea when he launches his 200m bid on Friday, just five days after his dramatic disqualification from the 100m final after a false start.

There are not too many flaws on Bolt's CV coming into the 200m. He is reigning world champion, Olympic gold medalist and world record holder (19.19 sec) and also world leader this season with a run of 19.86 sec in Oslo, Norway.