12 × 12 Binairo is where solving becomes bookkeeping as much as logic. With 144 cells and six of each digit per line, you juggle several half-finished lines at once, and the payoff for disciplined counting grows: noticing a row is one 0 short of its quota can cascade through three or four columns.
Expert solvers work in passes — sweep for pairs and sandwiches, then re-count every line, then compare near-complete rows against finished ones for uniqueness eliminations. The rhythm matters more than any single trick.
Boards this size reward an uninterrupted session. If you want the same depth with less commitment, step down to 10 × 10; if you want more, 14 × 14 awaits.