In a sense, every stride you take during a race is a microdecision: will you speed up, slow down, or maintain your current pace? But some decisions are more consequential than others. As Korir and Cheruiyot telescoped away, leaving the shrapnel of the exploded lead pack in their wake, I had to decide how hard to chase. I wasn’t concerned about pace or splits; I had logged enough miles on the razor’s edge, over the previous decade, to be able to feel in my gut precisely what was sustainable and what wasn’t. I was as fit as I had ever been, and—let’s be honest—wanted cash; but I was also disciplined and pragmatic. As the runners around me abruptly launched into what seemed like a near-sprint, I accelerated more steadily, hoping to hit the the maximum pace I could sustain for the eight remaining miles. Soon all two dozen runners in the lead pack were receding into the distance in front of me. But I hoped to see at least some of them again.