Simple rules are always great. So the challenge from cockbainevents.com must be brilliant:

But, well. Turned out that there are some twists to it. I was absolutely unprepared for the fact that there are months not offering a 50 miler per default. Race months fine – don’t even need to to think about them. But what about the others? Strange. Another striking finding was that 50 mi are kind-of-longer compared to a standard long run (around Marathon). And, even more surprisingly, substantially longer. Like almost double – a distance which requires some determination to get it done outside of races.

Taking all that together this challenges requires just as much determination, dedication, consistency and grid to make it unpleasant. And I think that’s exactly what Mark had in mind. All is well. Clear recommendation. Its just that tiny amount of uneasiness that makes it extremely annoying.