USA has won three straight gold medals in the past three editions of the IAAF World Championships in the women’s 4x400m relay and they are the top pick in these championships as well.
Together with their two successive sets of Olympic gold medals, the USA has grabbed the win in the last five global championships from 2007 to 2012.
Russia was the last nation to break the US stranglehold on this event when they won at the 2005 World Championships in Helsinki so, although the USA is the favourite here too, Russian home crowd will be hoping for a change and perhaps there is a chance that an upset could happen.
Two runners have featured in all of the last five US winning teams.
Allyson Felix has run the second leg in each of the five and Sanya Richards-Ross has also been a part of all five teams, anchoring four times and featuring on the opening leg in Daegu 2011.
However, in Moscow, Richards-Ross will be absent from the team and the USA will have to rely on new athletes to try to carry on the winning streak.
Only two athletes in their squad here have been part of previous winning teams in a final, Francena McCorory anchored the 2011 Daegu winning team and ran the third leg at the London 2012 Olympic Games while Jessica Beard carried the baton on the third leg in Daegu.
Ashley Spencer, Natasha Hastings, Joanna Atkins and Rebecca Alexander are all without final experience in a major championship 4x400m Relay, at least as seniors.
The Russians are the only team who can realistically upset the USA, having led the world prior to Moscow after a US quartet ran 3:22.66 at the Penn Relays in April.
They have two runners in the team who have gone under 50 seconds this season, Antonina Krivoshapka and Kseniya Ryzhova, and they also have national champion Kseniya Zadorina and Tatyana Firova, the latter having run under 50 seconds last year and who has been close to that mark this summer.
Even the reserves Yuliya Gushchina (49.28 in 2012) and Anastasiya Kapachinskaya (49.35 in 2011) have gone under 50 seconds in their careers and only Zadorina's best is slower, at 50.55. By contrast, only two of the US runners, Hastings and McCorory, have run under 50 seconds.
Of the other teams, Jamaica should be the strongest candidate for the bronze behind the top two teams while World indoor champions and 2013 European Team Championships winners Great Britain is also a strong contender. Ukraine should also make the final with France, Nigeria and Czech Republic the most likely candidates to progress from the heats.
Mirko Jalava for the IAAF