Case LinkedIn Mini Sudoku #337: 6×6 grid, 14 fixed digits, 22 open cells. Region layout: 6 regions, 6 cells each. Full placement map: R2C2=4, R2C6=6, R1C5=5, R1C6=4, R2C3=5, R3C6=3, R3C3=1, R3C4=6, R4C3=3, R1C3=6, R1C1=3, R1C2=2, R4C1=4, R4C4=5, R5C1=6, R5C4=3, R5C5=2, R6C1=5, R6C2=3, R6C4=4, R6C5=6, R6C6=1.
Board spotlight: Most fills come from scanning rows and columns for cells where only one digit fits — classic naked-single territory. Region geometry (6 regions, 6 cells each) shapes which unit yields the next hidden single.
Evidence block 1: R2C2=4, R2C6=6, R1C5=5, R1C6=4. Chain of reasoning ties givens to these cells via Naked single, Naked single, Naked single, Naked single.
Evidence block 2: R2C3=5, R3C6=3, R3C3=1, R3C4=6. Chain of reasoning ties givens to these cells via Naked single, Naked single, Naked single, Naked single.
Evidence block 3: R4C3=3, R1C3=6, R1C1=3, R1C2=2. Chain of reasoning ties givens to these cells via Naked single, Naked single, Naked single, Naked single.
Evidence block 4: R4C1=4, R4C4=5, R5C1=6, R5C4=3. Chain of reasoning ties givens to these cells via Naked single, Naked single, Naked single, Naked single.
Evidence block 5: R5C5=2, R6C1=5, R6C2=3, R6C4=4. Chain of reasoning ties givens to these cells via Naked single, Naked single, Naked single, Naked single.
Evidence block 6: R6C5=6, R6C6=1. Chain of reasoning ties givens to these cells via Naked single, Naked single.
Mid-solve checkpoint: 11 cells remain after the first half of the chain. Row-scan heavy boards often accelerate once two or three regions close — watch for hidden singles in tight blocks.
Late game: final batches collapse quickly when rows and columns near completion. Every row, column, and region contains digits 1–6 with no repeats. Completed path: R2C2=4, R2C6=6, R1C5=5, R1C6=4, R2C3=5, R3C6=3, R3C3=1, R3C4=6, R4C3=3, R1C3=6, R1C1=3, R1C2=2, R4C1=4, R4C4=5, R5C1=6, R5C4=3, R5C5=2, R6C1=5, R6C2=3, R6C4=4, R6C5=6, R6C6=1.
Verdict: placement set R2C2=4, R2C6=6, R1C5=5, R1C6=4, R2C3=5, R3C6=3, R3C3=1, R3C4=6, R4C3=3, R1C3=6, R1C1=3, R1C2=2, R4C1=4, R4C4=5, R5C1=6, R5C4=3, R5C5=2, R6C1=5, R6C2=3, R6C4=4, R6C5=6, R6C6=1 satisfies all sudoku constraints. Case closed.