I don't think they sell out. I finished the Unbound 200 and BWR (SD) last year and I think there 4000+ riders at the event with close to 3000 attempting the longer distance. I could be wrong but at one point they had just over 300 finishers for the Waffle. I think they eventually found data to double that number.

Either way its not a good finishing rate.

While I fought through heat exhaustion to finish, it was like 118 F in the coming back over from the desert. I gave away my water to riders waiting for SAG pickup and there were, in my opinion, a lot of EMS activity and at least one life flight helicopter called. Maybe two?

I will do Unbound again. I will likely not do another BWR.