Expert (20×20)
Grid Size: 20 × 20
For when you want to take on the top difficulty with advanced techniques.
Expert is a 20×20 grid, where you must bring in full rescans and sometimes even testing for contradiction. To find a single move, you have to read the interaction of several lines.
It is designed to be solvable with logic alone, however long it takes. The very process of the big picture slowly emerging is its own reward.
- Sweep every line first and fill in all the cells confirmed by overlap.
- Rescan the most recently changed lines first to break through a deadlock.