I will add videos here if I ever find them.
These races were fascinating from a tactical perspective. Races with 14 participants are crowded and it was interesting to see how runners dealt with this challenge.
Heat 1 starts so slowly that Nancy Chepkwemoi decides to overtake the entire field in the first bend. That’s basically a sound decision, but look what happens after that. The pace remains slow, and it seems like almost every other runner in the field makes the same decision as Chepkwemoi did. There’s constant stream of athletes moving towards the front in the outside lanes. I haven’t seen a race with this much movement through the whole field for a long time.
Most of these overtakings look like good decisions. If you can pass the entire field easily, do it! With everyone moving up on the outside, Chepkewmoi falls back almost to last place. The reason for this seems to be that she runs tentatively and constantly leaves a gap between herself and the runner in front of her, and others keep moving into that gap. Chepkwemoi then has to make a panic move to the outside at the 1000m mark, runs the 1100-1200 in lane 2 and then runs out of energy.
Dibaba displays great tactics in heat 1, moving to second place at 700m and staying there until the sprint. Perhaps her reputation helps her a little bit, since the runners behind her clearly prefer to stay there, and do not try to move ahead of her even when the pace remains relatively slow through the 700-1100 lap.
Brenda Martinez runs the whole race out in lane 2. Even as many other athletes move past her towards the front, she always stays put in the middle of the field. I suppose she wants to make sure she’s in a free position when the sprint begins, but she clearly runs the longest distance of anyone in this race and does not look very comfortable sprinting on the final straight. It is often preferable to run at least some parts of the race in lane 1, either at the front or at the back as Dibaba did. In the semifinals Martinez will have to save more energy for the sprint if she wants to make her way to the final.
Heats 2 and 3 were both fast and therefore non-tactical. The pacemaker from heat 2 did not qualify, but Sifuentes, who set the pace in heat 3, did go through to the semifinals.