A lit core sits inside a stack of concentric rings. Each ring is a solid collar with a few gaps cut through it, and each one turns on its own: press anywhere on a ring and drag, and that whole collar follows your finger round, snapping to the nearest tooth when you let go.
Light leaves the core along one heading and gets exactly as far as the gaps allow, so the board always shows you a stub of beam stopping dead against the first collar that disagrees. That is the entire readout — you never have to guess which ring is wrong, only what to do about it.
Line up one gap per ring on a single heading and the beam reaches the rim. The outer rings are the cheap ones to move and the inner ones decide the heading, which is why the obvious first turn is usually the one to undo.
Every board is generated and then solved before it ships, so the "best" you are chasing is a real number. No timer, no way to lose, and it all works offline.
Rotate each ring until the gaps line up and the light escapes the core.