Would you rather run 2:40 at a nondescript marathon or win a 100-miler that had 12 competitors?

Depends who those 12 competitors were. If it was Scott Jurek, Krupicka, Roes and other guys like that, I'd go with the 100 win.

I'd kill to run a 2:40.

bump

I could do both. Like everyone else on letsrun.

2:40. Even a dude could win a few "nondescript" marathons with 2:40.

I've run faster than 2:40. But honestly, I'd pick that. Running on your own for 100 miles sounds really boring. If the 100-mile race had some meaning to it (like if it were an important event or championship), then I'd pick that. But I try not to run marathons where I think I'll be by myself the whole way, it's not like there are tactics among 2:40 marathon runners, the time basically tells you how fast you can go.

As I've run sub-2:40 before, I'd be more curious to run the 100 miles. Not that I'd care about the win though. I'd just be more inclined to see how my body and mind respond to running 100 miles.