Tyson Gay, United States (men’s 100m): No defending world champion – Justin Gatlin is serving an eight-year ban for drug-taking – but Asafa Powell has a new challenger in Tyson Gay. Powell, the world record holder, who has yet to win a global title, and Gay, the fastest man of the year, have not met this summer.

Jeremy Wariner, United States (men’s 400m): Filling Michael Johnson’s shoes would seem the impossible task but Wariner has at least got them out of the museum and is trying them for size. Can he get as far as doing up the laces? World and Olympic champion at 400 metres, Wariner is seeking a second successive world title - Johnson won four at the distance – and is attempting to close in on Johnson’s world record of 43.18sec.

Abubaker Kaki, Sudan (men’s 800m): The ‘unknown’ on this list outside Africa, Abubaker Kaki may not be for long. Possessing a blistering finish, he is on a run of championship wins this summer, with Arab, East Africa and All Africa Games titles. At 18, can he bring Sudan, in its time of crisis, its first medal in the history of the World Championships?

Alan Webb, United States (men’s 1,500m): Having broken the 25-year-old United States record for the mile this summer, and leading the 1,500 metres world rankings, Alan Webb attempts to become the first non African-born winner of this event since Steve Cram in 1983.

Craig Mottram, Australia (men’s 5,000m): Like Alan Webb in the 1,500 metres, Craig Mottram could break an African stranglehold stretching back to the second World Championships in 1987. Not since Eamonn Coghlan, from Ireland, won in 1983 has the 5,000 metres title moved out of Africa.

Kenenisa Bekele, Ethiopia (men’s 10,000m): After winning both World Cross Country titles – long and short course – every year for five consecutive years, Kenenisa Bekele failed to finish in the defence of his long course title in March. Another defeat, and failure to record a third successive world 10,000 metres title, would suggest that Bekele is not the athlete he was.

Sanya Richards, United States (women’s 200m): The world woman athlete of the year in 2006, Sanya Richards failed to qualify for the 400 metres here after illness left her short of training for the US trials. But she did qualify at 200 metres and looks a good bet to win gold in her ‘second’ event.

Yelena Soboleva, Russia (women’s 1,500m): With a degree in woodwork industry technology, Yelena Soboleva is a woman with credentials. On the track they include the world indoor 1,500 metres record. Now, aged 24, and with four successive wins on the international circuit to her credit, she looks likely to add a world title to her CV.

Yelena Isinbayeva, Russia (women’s pole vault): Gardeners talk to plants to make them grow, Yelena Isinbayeva talks to her pole and keeps the world record growing. She has never revealed the secret of what she says to her implement as she lines up to jump, suffice to say that it has responded with 11 outdoor world records, three indoors, and an Olympic title. Defending world champion.

Carolina Kluft, Sweden (heptathlon): As dominant and ebullient as Yelena Isinbayeva is, Carolina Kluft remains the sport’s top entertainer. Unbeaten for five years in multi-events, Kluft not only runs, jumps and throws in combination better than any woman of her generation but she has fun doing it – and shows it.