Draw a Perfect Circle

One stroke, all the way around the dot. Start wherever you like and run it whichever way you like: the stroke sets its own frame, and the direction is whichever way it first turns. Lift early, turn back on yourself, or wander onto the centre dot or too far out of the ring and the stroke is void. Close it and the run is measured: the sweep is resampled at a hundred and eighty equal angles, a best-fit circle is fitted to those radii, and the score is how little your stroke wandered off it, as a percentage. The fit forgives drawing around the wrong point, because being off centre is not being out of round, so the whole penalty lands on the wobble. Nothing but the stroke itself is submitted, and the accuracy on the global leaderboard is the one the server computed, not the one this page did.