How Perceptle Scores Work
Every Perceptle result comes from one curve applied to five different raw errors. A dot count is judged as a share of the board, a Track click as pixels, an Angle as degrees, a Tempo run as milliseconds and a Split as a share of the line. This page sets out the formula, the sigma behind each event, and what a score in the seventies actually costs you in each one.
The one curve behind every Perceptle score
The formula is the same everywhere: score = 100 × e^(−0.5 × (error ÷ σ)²), rounded to a whole number and clamped between 0 and 100. The only thing that changes between events is σ, the size of the miss that scores 61. Two sigmas score 14, and the curve is symmetric around zero, so being early and being late cost the same.
This is why the middle of the range is where most practice time is spent. Between B and A the curve moves almost vertically: on a 64-dot Count board, six dots off scores 90 and three dots off scores 97, while the same three dots above 95 are worth almost nothing. A result in the sixties has more room above it than a result in the nineties has anywhere.
The sigma of each Perceptle event
Perceptle states sigma in the unit the event is measured in, which is why the five numbers below are not comparable to each other. They are the miss that scores 61 on a normal question, followed by the same figure on the Friday variant.
| Event | Sigma (normal) | Sigma (Friday) | What 1σ is |
|---|---|---|---|
| Count | 0.2 | 0.32 | 20% of the dots on the board |
| Track | 60 | 90 | 60 pixels of an 800-pixel stage |
| Angle | 8 | 14 | 8 degrees |
| Tempo | 60 | 85 | 60 ms of combined drift and jitter |
| Split | 0.05 | 0.1 | 5% of the line |
What each grade line costs in real units
Grade bands are fixed at 95, 85, 70, 55 and 40 for every event, so the raw miss each band allows varies with sigma. The table turns the bands back into the units you actually see on the result.
| Event | S | A | B | C | D |
|---|---|---|---|---|---|
| Count (% of board) | 6.7% | 11.6% | 17.0% | 22.0% | 27.2% |
| Track (px) | 20 | 34 | 51 | 66 | 81 |
| Angle (degrees) | 2.6 | 4.6 | 6.8 | 8.8 | 10.9 |
| Tempo (ms) | 20 | 34 | 51 | 66 | 81 |
| Split (% of line) | 1.6 | 2.9 | 4.2 | 5.5 | 6.8 |
Why the same Perceptle score is not the same miss
A 76 is a 76 everywhere on the site, but it stands for different amounts of error in each event. On Track it means 44 pixels of an 800-pixel stage, about five and a half percent of the width. On Angle it means about 5.9 degrees of a dial. On Split it means 3.7% of a line. The grades travel; the units do not.
The numbers also say something about relative difficulty, and this part is a judgement rather than a measurement. Count has the least forgiving Perceptle sigma in practice, because 20% of a board of 64 is thirteen dots, and a thirteen-dot miss is easy to make. Tempo is the opposite: 60 milliseconds is a wide window in a task with no visual reference, which is why a Tempo score often looks generous next to the same person’s Track score.
So compare a score with the same event last week, not with another event in the same round. The radar exists for the comparison across events, and it can be read as a shape without pretending the five axes are interchangeable.
How to read your own Perceptle result in one pass
Start with the error line under the score, not the score. It states the miss in the event’s own unit, which is the only number that tells you what to change.
Then check the grade against the band above it. If the error is within a few percent of the next line up, one adjustment is all that separates them, and the adjustment is usually a bias rather than a skill.
Finally, decide whether the miss has a direction. A signed error that repeats can be subtracted. A scatter with no direction means more rounds, not a new technique.
Scoring questions
How is a Perceptle score calculated?
One formula covers all five events: 100 × e^(−0.5 × (error ÷ σ)²), rounded and clamped to 0 to 100. Sigma differs per event, so the same score stands for a different raw miss in each one.
What score do I need for each grade?
Perceptle fixes five lines: S at 95, A at 85, B at 70, C at 55 and D at 40. Anything below 40 is an F. Because the same lines apply to every event, the raw error each one allows varies with sigma.
How many points is one sigma worth?
A miss of one sigma scores 61 and a miss of two sigma scores 14. Half a sigma scores 88, so the curve is steep in the middle and flat at the top.
Why is my Angle score lower than my Track score?
Because sigma is smaller in Angle: 8 degrees against 60 pixels. The same grade needs a much smaller miss in degrees than it does in pixels, and a two-degree overshoot can cross a whole band.
Does the Perceptle full round average the five scores?
Yes, as a plain mean rounded to a whole number, with equal weight for every event. One weak event pulls the total down by a fifth of its shortfall, which is why fixing the lowest score moves the total fastest.
Is a practice score comparable with a daily test score?
The Perceptle curve and the grade lines are the same, so a score means the same thing in both places. The questions are not: practice deals a random one, while the daily round uses a fixed set, so the two numbers are comparable in method rather than in difficulty.