Your example of catching a baseball is apt, but disproves your point.
From afar (where gravity and drag would dominate), it's been fairly conclusively shown that humans primarily rely on the so-called gaze heuristic to meet the ball at the appropriate point.[1] In the gaze heuristic, you continually adjust your position so that the ball stays at a fixed point relative to the horizon or some other reference point. If you keep doing this, you will meet the ball. Studies have shown that if you disrupt this process--such as by removing reference points or the ability for people to continually move so that their position, the ball, and the reference stay relatively fixed--people suck at catching the ball.
Now, we could argue that this heuristic itself has rules, and in studying the rules we can master them. But the salient point is that, especially in this case, the human is an active participant in the heuristic. Moreover, it works because it trades a nearly infinite number of variables (the heuristic still works even as winds change) for a few simple variables which are intrinsically dependent on context--specifically, context other than those things directly acting upon the ball. And the gaze heuristic isn't the only heuristic used to catch a ball, just the one that works best from afar. The brain simultaneously applies many heuristics, most of which we don't even understand, yet.
Ultimately there's irreducible complexity here and no optimal solution. There's a trade-off. And because our environment is constantly changing (e.g. display material, lighting, and the place and time people read evolve over the years) the trade-offs will change. To be sure there's science involved, but it will never be an _exact_ science in the sense of being able to create a perfect font or completely enumerate a set of typographical rules.
[1] I think I learned this from "Rationality for Mortals: How People Cope with Uncertainty" by Gerd Gigerenzer.