> I believe this is because of the horizontal symmetry ambiguity. One quick test for this would be to make the strips 2 pixels wide. It's interesting to watch

> I believe this is because of the horizontal symmetry ambiguity. One quick test for this would be to make the strips 2 pixels wide. It's interesting to watch the random walk that it does, and I think that problem would remain. Once it has made some wider strips that should be adjacent but aren't, the strips tend to randomly move between them, but there is no reason to prefer progress in one direction or the other. I'd be interested to see what happens if you only allowed moves in one direction, e.g. only allowed a column to be inserted to tbe right of where it was.