Medium Binairo boards require advanced counting: instead of reacting to single cells, you consider every legal way an entire row or column could still be completed. Take a row that needs two more 1s across four empty cells — some placements would create three-in-a-row, so they're off the table. If every legal completion happens to agree on one cell, that cell is decided, even though no single neighboring clue forces it.
In practice you don't enumerate exhaustively — you learn the recurring shapes. A line ending in _ _ 0 0 with one 1 left to place, an interior gap that only one digit can straddle, a quota that forces digits to spread out. Each shape is a completion argument compressed into a glance.
This is our everyday tier — all 90 boards in the daily rotation are medium — enough resistance to satisfy, never a grind. If a board stalls, find the line with the fewest empty cells and work out what it can still become.