Novlene Williams-Mills anchors Jamaica to gold in the 4x400m at the IAAF World Championships, Beijing 2015 (Getty Images) © Copyright
Preview London, UK

Preview: women's 4x400m – IAAF World Championships London 2017

Two years ago Jamaica pipped the USA – known to be the 4x400m relay powerhouse – to gold (3:19.13 to 3:19.44) with Great Britain taking third more than four seconds back in 3:23.62. It was Novlene Williams-Mills, who overtook Francena McCorory in the closing metres to lead Jamaica to their first victory in this event since Edmonton in 2001. However, the US squad made no mistake last year at the Rio Olympics, reversing the finishing order from 2015 with their Jamaican rivals while Great Britain took another bronze. 

On paper, it looks likely to be a battle between the US and Jamaica again in London too. The US women collected their third consecutive 4x400m title at the IAAF World Relays in The Bahamas in April, and with such strength in depth and the fastest time in the world this year by a national side, they arguably start as favourites.

The US squad boasts four of the five fastest female 400m runners in the world this year, all of whom have run 50.00 or quicker, headed by nine-time world gold medallist Allyson Felix (49.65) and world indoor bronze medallist Quanera Hayes (49.72).

However, Jamaica also boasts 2015 world and 2016 Olympic 400m bronze medallist Shericka Williams (50.05), Chrisann Gordon (50.13) and the highly experienced 2007 world 400m bronze medallist Williams-Mills (50.14), so will undoubtedly put up a strong fight.

The battle for bronze could end up being between the World Relays silver medallists Poland, The Bahamas  - boosted by Olympic 400m champion Shaunae Miller-Uibo (49.77) – and based on their major championships record in this event, Great Britain, although the latter arrives with a somewhat youthful squad and will not be able to call on the experience of former world and Olympic champion Christine Ohuruogu, who was not selected for the team.

However, so much can happen in a relay event, so the finishing order rarely goes according to the formbook. Although getting the baton around is not as big a challenge for a 4x400m team as for a sprint relay, spreading the effort efficiently over one lap is crucial. Taking a lot of ground out of the opposition in the first half of the race makes for exciting racing, and a lot depends on who is still standing on the final day of a World Championships as well as the running order.

Emily Moss for the IAAF