Sudoku time benchmarks
| Level | Average solver |
|-------|---------------|
| Very Easy | 3-5 min |
| Easy | 5-10 min ← target |
| Medium | 10-20 min |
| Hard | 20-40 min |
| World record | 1:23 (Tantan Dai, 2025) |
Solving strategy
Step 1: Scan obvious singles (1-2 min)
- Find cells where only ONE digit fits
- Check row, column, and 3×3 box
Step 2: Hidden singles (2-3 min)
- In each row/col/box — find numbers that fit only ONE cell
Step 3: Pencil marks (3-5 min)
- Write all possibilities in small corners
- Cross out as you fill cells
Step 4: Naked pairs (advanced)
- 2 cells with only [3,5]? Those numbers are locked
- Remove 3,5 from other cells in that row
Benefits
- +19% working memory (Cambridge 2024)
- 38% lower Alzheimer's risk
- Better logical thinking
- Stress relief
30-day improvement
| Level | Baseline | Goal |
|-------|----------|------|
| Beginner | 15 min | 8 min |
| Intermediate | 8 min | 5 min |
| Advanced | 5 min | 3 min |
Tip: Solve one Sudoku every morning — wakes up your brain