We have a pretty big back yard. Its ~90M long x ~40M wide, and aside from trees we've planted it's mostly grass and mostly flat. It's like a badly maintained football field or something.
On one side, there is a ~2M x ~1M section of mud caused by a drainage issue. It's the only muddy area in that whole space.
Yet without fail the automower will drive itself in to that space every single time it leaves the dock. Every morning I pull it out, and every afternoon its back in there. Most of the time I need to rescue it before I head to bed too.
How? It mows like the DVD logo that bounced around TV screens back in the day, just randomly hits a boundary and heads off in a random other direction yet somehow always ends up in that relatively tiny space within about 3 boundary rebounds.
I need a mathematician to work out the odds cause from my perspective its 100% at the minute.