Eight must-watch events at the Athletics World Championships in Beijing

For nine days, some of the planet's fastest men and women will gather in the Chinese capital of Beijing to compete against each other in the Bird's Nest Stadium.

A total of 47 events have been scheduled for the Aug 22-30 meet. Here are eight standout events of the competition and the main protagonists.

The Kenyan pair of Paul Tanui and Geoffrey Kamworor pose the biggest threat to Farah's defence though. Both men have clocked sub-27min times this year and have the ability to pull off a shock victory.

Gatlin has served two suspensions for doping but at 33, looks in the best shape of his life and has posted four of the season's best timings over the century sprint. His last defeat over 100m was in Sept 2013.

But if there is one man who can rise to the occasion it is the lanky Jamaican. Despite some niggling injuries in the past two years, Bolt is a fierce competitor who will want to prove his critics wrong and show he remains the undisputed king of the track.

Only three men (world record-holder Jonathan Edwards and 1996 Olympic champion Kenny Harrison and 2013 world champion Teddy Tamgho) have cleared 18m in the past 20 years until both Pichardo and Taylor added their names to that list this season.

On five occasions, in three separate competitions - the Doha and Lausanne IAAF Diamond League meetings and Havana's Barrientos Memorial - the pair have exceeded 18m with Taylor, the 2012 Olympic champion, maintaining a 3-2 edge.

This month is the 20th anniversary of Edwards' 18.29m world record and for the first time that mark could come under serious threat.

There, in the principality, Genzebe clocked an incredible 3:50:07 to break the previous mark of 3:50.46 set by China's Qu Yunxia, which was set 1993 Chinese National Games at a time when doping was more pervasive and commonplace than it is today.

Genzebe could double up as she is also competing in the 5,000m and has already posted three of the year's five fastest timings in that event.

He has also lost his last six head-to-head encounters against his younger Botswana rival Nijel Amos, 21, who finished second to Rudisha at the London Games three years ago. Another young gun to watch out for is Amel Tuka. The 24-year-old Bosnian has clocked the season's fastest time and has already beaten Amos and defending world champion Mohammed Aman of Ethiopia.

Anything less than a victory for Pole Anita Wlodarczyk, who won this competition in 2009, would be regarded as one of the major shocks of the competition.

The 30-year-old has been in breathtaking form of late and last month became the first woman in history to surpass the 80m barrier with her 81.08m throw in Cetniewo, Poland.

The 2012 Olympic silver medallist also owns the six best throws in the world this year and her world record is more than 5m more than her closest rival and 2007 world champion Betty Heidler of Germany.

At 1.96m, the Jamaican's height should give him the edge over the longer distance but he has yet to hit his stride in this event, a pedestrian 20.13sec - almost a second slower than his 19.19sec world record - set in May his year's best effort.

Gatlin has gone below 20sec four times in 2015 and will go into this race with plenty of confidence, particularly if he has the 100m title in the bag.

The SEA Games champion's 23.60sec personal best would not place her among the year's top-226 rankings for the 200m.

The race has been thrown wide open though with the absence of 2012 Olympic champion Allyson Felix. The American has opted to compete in the 400m, leaving compatriot Candyce McGrone and Dutch sprinter Dafne Schippers, with the year's second and third-fastest timings respectively, to seize the initiative. Do not overlook two-time 100m Olympic champion Shelly-Ann Fraser-Pryce either in a star-studded field.

jonwong@sph.com.sg