Looking at some US JWOC splits

I spent some time looking at splits for the US women at JWOC. I was particularly interested in Hannah Burgess' races. I look at her training on AP now and then, but I've never met her. Hannah was the best US woman in the sprint and the worst in the long. But, what caught my eye was that she was the steadiest in both races. If you look at her split graph you'll notice that her line is the