Last year, Sokwakhana Zazini left Nairobi as one of the brightest U18 talents on the planet. This year, the 17-year-old South African intermediate hurdler will arrive in Tampere ready to pick up where he left off.
Holder of the U18 world best, Zazini has continued to impress in full lap races, lowering his personal bests over the 400m flat to 45.86 and over the senior height 400m hurdles to 49.32. That's nearly half a second faster than the world's next quickest, Cory Poole of the US.
In all but one of his six finals this year, Zazini has dipped under 50 seconds; only three others have gone under the mark this year, and all just on one occasion. In his most recent outing, Zazini was an impressive fourth at the Odlozil Memorial in Prague on 4 June.
Poole, a semi-finalist at World Youth Championships in 2015, chased the 50-second barrier all season in his first year at the University of Florida, and it finally came when winning the national junior title on 16 June in 49.71. He'll need to arrive in consistent sub-50 shape to seriously challenge for the win here.
Sergio Esquivel of is the third 2018 sub-50 man in the field, but is largely untested outside of his native Mexico. Beginning the year with a 50.19 best, the 19-year-old improved to 49.90 on 3 June in Monterrey, a national U20 record.
Looking to fill the void left by 2014 and 2016 champion Jaheel Hyde, Jamaica comes armed with an admirable 1-2 punch made up of Malik James-King and Leonardo Ledgister. James-King took the national title in mid-June in 50.23, just ahead of Ledgister who clocked a personal best 50.31. Malik's personal best of 50.03 dates back to late March.
Meanwhile, Poole will be backed by Quivell Jordan, who arrives with 50.21 credentials. That's just marginally quicker than the top Swede Carl Bengstrom, who has clocked a 50.21 national U20 record this season, his first tackling the event. He appears to be a fairly quick learner.
Bob Ramsak for the IAAF