It is a coincidence that the text is discussing changes in situation and the sentence necessitates a page turn to continue on and complete the transition. And a further co-incident is the theme of chance.

For Cage, the composer is like the hero of the legend, chance composition is like the rolling of the metal ball, and the resulting musical form is the passage from [pb] one situation to another.
James Pritchett. The Music of John Cage (Cambridge University Press, 1983; rpt 1996) pp. 77-78.

And in case you were wondering about the legend and the metal ball. It's Irish.
A story from Irish folklore that Cage refers to in his lectures and writings is useful analogy to this model. The story deals with a hero who goes on a quest with the aid of a magical horse — a "shaggy nag" — that gives him advice along the way. The horse gives the hero a metal ball and instructs him to cast it in front of them and to follow it wherever it leads. The hero does this, and thus, by abandoning himself to chance, passes safely through his various trials.

And so for day 986