About 15×15 Masyu
A 15×15 Masyu grid has 225 cells. Your goal is the same at every size: draw a single closed loop through the centres of cells so that it passes through every pearl. Black pearls are corners with straight legs; white pearls are straight segments with a turn next to them. 15×15 boards are recommended for experienced solvers who enjoy a longer session and multi-region reasoning.
| Difficulty | Puzzles | Average pearls | Typical time |
|---|---|---|---|
| Easy | 80 | 88 | 15–25 min |
| Medium | 80 | 69 | 20–40 min |
| Hard | 80 | 55 | 30–60 min |
Fewer pearls usually means a harder puzzle: there are fewer starting points, and more of the loop has to be deduced from global rules. Times are a rough guide for an experienced solver.
Tips for 15×15 boards
- Solve in sweeps: scan every pearl in reading order, then every loop end, then every empty region.
- Use the parity (checkerboard) argument to decide whether an isolated pocket can be entered.
- Save your progress — boards autosave, so you can come back later without losing a single line.
New to these patterns? Read our Masyu strategy guide with 14 illustrated techniques, or go back to basics with how to play Masyu.