How the scoring works
Your stroke is compared against the real border in both directions, then mapped onto a 0-100 scale. Here is exactly what each band means, measured against synthetic drawings of known quality.
| Attempt | Avg deviation | Score | Verdict |
|---|---|---|---|
| Traced exactly | 0.0% | 100 | Cartographer |
| Drawn from memory, good | 1.9% | 74 | Solid |
| Drawn from memory, average | 3.6% | 56 | Recognizable |
| Right shape, wrong proportions | 6.0% | 34 | Rough |
| Mirrored or upside down | 9-10% | 19-22 | Abstract |
| Random scribble | 9.8% | 11 | Abstract |
What is normalised away
Position and size are removed before comparing, so you can draw anywhere on the canvas at any size. Shape, proportion and orientation are kept, because those are the parts you are being asked to remember.
Questions
Does it matter where on the canvas I draw?
No. Your drawing and the real outline are both centred and scaled to the same box before they are compared, so position and size are free.
Does size matter?
No. Scale is normalised away. Drawing small and drawing large score the same, as long as the proportions match.
Does rotation matter?
Yes. Rotation is deliberately not normalised — an upside-down outline is the wrong answer, and scores like one.
Can I cheat by scribbling everywhere?
No. The score measures distance in both directions: how far your line is from the real border, and how much of the real border you left uncovered. Covering the canvas fails the first test; a tiny scribble fails the second. A random scribble measures around 11 out of 100.
What is the deviation percentage?
The average distance between your line and the real border, as a share of the outline's own size. Around 2% is a good freehand attempt; 10% means the shape did not match.