Hey look, I'm part of a trend! :D But seriously, I'm a bit confused. Early on, they refute "Just the slow are getting slower" but near the end they make almo

Hey look, I'm part of a trend! :D But seriously, I'm a bit confused. Early on, they refute "Just the slow are getting slower" but near the end they make almost the same claim. The trick they play is to shift from examining the N fastest to examining the N slowest. In other words, the two samples "prove" nearly contrary things because they're both incomplete. Also, the real meaning of N fastest/slowest changes a lot with race size. Using percentiles would have been a better (and more obvious) choice. BTW, I love RunRepeat and have used it extensively as part of my research the last several times I've bought running shoes. Highly recommend.