Athletes pass the baton during the 4x400m (© AFP / Getty Images)
A US quartet has won this event at 15 of the 17 previous championships; with Kahmari Montgomery and Wilbert London, two of the season's five fastest 400m specialists entered, there’s little to suggest that a 16th title is not on the horizon.
The strongest threat appears to come from Botswana, who'll arrive armed with Baboloki Thebe and Karabo Sibanda, the former the world U20 leader at 44.22 and the latter the world's sixth fastest at 45.40, and both medal favourites in the 400m.
Jamaica, with world youth 400m champion Christopher Taylor, and Trinidad and Tobago will arrive with medal ambitions as well. Germany will start as the world U20 leaders at 3:08.52.
Bob Ramsak for the IAAF
