About a year ago, a friend and I went on a hike in Victoria, Australia. At a campsite, there was a circular fenced section housing a miniature train set for kids or school groups to play with.

We spent a long while trying to balance along the top of the fence, and walk the full circle, which was quite challenging.

We are now betting what the diameter of the circle fence was.

I say 11 meters.

My friend says 20 meters.

This market will resolve yes if my prediction is closer to the real diameter than my friend’s.