Track action at this year's World Championships will end with the 4x400-metre relay. That's a return to tradition after a three-year experiment with big meets closed by the 4x100 metres. Tradition will also be restored at the 2016 Olympics as the 4x400m ends action on the track in Rio.
Usain Bolt produced spectacular anchor legs in the last moments of both the 2011 World Championships and the 2012 Olympics, with Jamaica winning both 4x100m finals in world-record time. Though there was no 4x100m record at the 2013 World Championships, Bolt was again the last man to cross the finish line first.
That won't happen in Beijing, the host city of the 2015 Worlds, or at next year's Olympics. The recently published Olympic athletics schedule has the 4x100m finals for men and women on day eight of the Games, with the 4x400-metre finals on day nine. The experiment is clearly over.
An Allyson Felix 200-400 double is as unlikely in Rio as it is in Beijing. On day six of the World Championships, Felix will have the 200m semis at 1940 local time and the 400m final 70 minutes later at 2050.
In Rio, while Felix will be defending her 200-metre title, there is also overlap between that event and the 400m. On day four of athletics, the 200m heats are at 2145 local time. The 400m final is a mere 90 minutes later at 2245.
When she did this double at the 2011 World Championships, the 400m was concluded two days before the 200m started. Unless the schedule is revised, it's hard to see her choosing to ignore an event where she is Olympic champion and three-time World Champion.
Michael Johnson must be shaking his head. Two decades ago, the American lobbied to get the events separated so he could try the 200-400 double. He succeeded and did the double at the 1995 Worlds and the 1996 Olympics.
The schedule changes at the Worlds and the Olympics end Bolt's role as a big meet closer and nix a possible 200-400 double by Felix.
Happily, it's not all doom and gloom. In keeping with tradition, the Beijing and Rio schedules make it possible for sprinters to run the 4x400m final.
During the experimental period, the 4x400m final came before the 4x100m final and sprinters might have feared they'd be flat before the sprint relay.
That fear has been removed.
n Hubert Lawrence has scrutinised athletics since 1980.