I like that analogy. It helps make it clear that we may have a "free will of the gaps", phrase borrowed from "god of the gaps". What we call free will, or a claimed ability to choose arbitrarily, may be an incomplete understanding of the input factors determine our subsequent behavior and experience of that behavior. The chess-playing algorithm you describe also seems analogous to a billiard ball, bouncing around a table due to prior and current conditions. The danger in calling it non-illusory choice (in chess playing algorithms or in humans) is that that word use may play to our cognitive biases, like calling rain "god tears" or cancer "wrongdoing punishment".