World record from the Jamaican ladies. Crazy culture they have going on - they will do some crazy things in true future, Jamaican development of talent has been second to none over the last 2 decades or so.
Japanese men win the 4x100 - and I’m not even particularly surprised. The Japanese 4x100 squad has been among the most consistent (maybe the MOST consistent) over the past few years. I think this is a harbinger of the future. Japanese senior men haven’t had great showings over the last 2 years or so at the international level, with the exception of the Eugene 4x400, but I think that when they get their stuff together (and I think that they will, very soon), they will be unstoppable. In Rio 2016 Japan got bronze in the 4x100 with no runners under 10, and in the next decade I think Japan will become the first country to run under 37 with no runners under 9.9. Bold prediction, but I think it will happen.