Letter A pattern lock
How to draw the letter A as an Android unlock pattern, step by step, on the standard 3×3 grid and on 4×4, with the security score PatternGuard’s analyzer gives each version.
The letter A on a 4×4 grid
Stock Android uses the 3×3 grid; 4×4 shows up in some custom ROMs and lock-screen apps, and the simulator supports it. The letter A can be drawn exactly on the 4×4 grid thanks to one Android rule most people don’t know: the stroke may pass over a dot you already used. That lets you go back over a line: in step 6 the stroke passes over dot 9 again.
- Start at dot 12 (row 3, column 4).
- Go to dot 11 (row 3, column 3).
- Go to dot 10 (row 3, column 2).
- Go to dot 9 (row 3, column 1).
- Go to dot 13 (bottom-left corner).
- Go to dot 5 (row 2, column 1), passing over dot 9 again.
- Go to dot 2 (row 1, column 2).
- Go to dot 3 (row 1, column 3).
- Go to dot 8 (row 2, column 4).
- Finish at dot 16 (bottom-right corner), passing over dot 12 again.
PatternGuard’s analyzer gives it 56/100 (Moderate): 10 dots, 2 crossings, starting at the row 3, column 4.
The letter A on a 3×3 grid
An exact letter A isn’t possible on the 3×3 grid: Android never lets you select a dot twice, and this shape would need it. The closest pattern leaves out the line 2–6 and the line 4–7.
- Start at dot 2 (top middle).
- Go to dot 4 (middle left).
- Go to dot 5 (center).
- Go to dot 6 (middle right).
- Finish at dot 9 (bottom-right corner).
PatternGuard’s analyzer gives it 15/100 (Very weak): 5 dots, 0 crossings, starting at the top middle.
Is a letter A pattern safe?
Not really. Letters are among the first shapes anyone tries: research on real-world patterns found that about 1 in 10 is shaped like a letter, often the initial of a partner or a child (Løge, 2015). If your name or your partner’s name starts with A, this is one of the first patterns someone who knows you would draw.
A stronger way to use the letter A
If you like the letter A, don’t draw it on its own. Adding 2 dots after it keeps the shape you remember but hides it inside a longer stroke: 2 → 4 → 5 → 6 → 9 → 1 → 7 scores 50/100 (Moderate), against 15 for the plain letter A.
It’s still published here, so treat it as an example of the idea, not as a pattern to copy. The safest pattern is one of your own that doesn’t spell anything.
Why some letters can’t be drawn exactly
Android’s pattern lock has three rules: at least 4 dots, no dot can be selected twice, and if the stroke passes over a dot you haven’t used yet, Android adds it automatically. Passing over a dot you already used is allowed, which is how letters like P, R or F can be traced exactly. On 3×3, shapes with a closed loop or three or more loose ends (like A, B or O) still need one line left out or one line added; the 4×4 grid has more room, but not always enough.