Rojas and Dibaba taken to get the better of their epic battles

Day two
BBC2 and Eurosport 1, 9.30am Saturday
BBC1 and Eurosport 1, 6.30pm Saturday

Wayde van Niekerk, the heir apparent to Usain Bolt's title as the sport's most high-profile athlete, youthful talent Nafissatou Thiam and hammer hurler Anita Wlodarczyk all get their gold-medal bids off and running on Saturday, but the best bets lie elsewhere.

Qualifying for the women's triple jump starts on Saturday afternoon and another youngster with a huge amount of natural talent is taken to depose the Olympic and two-time world champion Caterine Ibarguen.

Ibarguen, now 33, is fifth on the all-time list but she faces 21-year-old Venezuelan Yulimar Rojas, who looks destined to top that list when she finally puts it all together.

Ibarguen beat Rojas to gold in Rio but their head-to-head battle is one-all this year. At 5-4 Rojas is the bet because this year's world leader is an almighty competitor, regularly producing her biggest jump in the sixth and final round, and she is capable of popping off a leap that could make this clash a no-contest.

The women's 10,000m final looks like being another head-to-head between two Ethiopians in Almaz Ayana, who smashed the world record in Rio, and the legendary Tirunesh Dibaba, who is chasing her ninth major gold.

The one complication is that neither athlete has been sighted on the track this season - Ayana due to injury and Dibaba because of her focus on the road.

If Ayana is in the same form as she was in Rio then there is only one winner but that is impossible to know and given the number of events she has pulled out of it is hard not to conclude that something is amiss.

Dibaba, on the other hand, has at least been bashing out good times on the road and is arguably the greatest female championship performer at this distance. She looks a vastly safer bet.

The men's 800m is another two-way contest, with Kenya's exciting youngster Emmanuel Korir taking on Botswana's Nijel Amos.

Korir is favourite and has the world-leading time (and three of seven sub-1m44s times this year) but he has been competing on the arduous US collegiate circuit.

Amos, who has a season's best within 0.08s of Korir - and two of those sub-1m44s times - has spent his entire season building to a peak for this race. The presence of the speedy Korir could even be a blessing as Amos has often been caught out in tactical affairs.

Joe Kovacs is worth a nibble in the men's shot put as, while Ryan Crouser should win, he should not be a 2-5 shot.

The pair have the nine longest throws between them this season, with Crouser owning seven, but there is only 8cm between them on their best efforts and Kovacs is a tempting price at 4-1 to defend his world title.

Recommendations
Y Rojas to win women's triple jump
1pt 5-4 Betfair, Paddy Power
T Dibaba to win women's 10,000m
1pt 11-10 Paddy Power
N Amos to win men's 800m
1pt 13-8 Betfred
J Kovacs to win men's shot put
1pt 4-1 Betfair, Paddy Power