Take a moment to visualize some iconic head-to-head finishes from recent global championships: Klæbo vs. Bolshunov in the 50 k, Oberstdorf, 2021; Nilsson vs. Johaug in the relay, Seefeld, 2019; Schumacher vs. Terentev in the relay, Lahti, 2019; Diggins vs. history in, well, you know, PyeongChang, 2018. What do these races have in common, besides drama, high-level skiing, and triumph and tragedy in equal measure? All of them feature a final downhill back into the...