LinkedIn 6x6 Sudoku #321: Pro-Tips Guide to Crack the Grid

Pro-Tips Guide: LinkedIn 6x6 Sudoku #321

If you're speed-running LinkedIn 6x6 Sudoku #321, don't waste time listing every cell. The grid cracks open when you focus on one specific area. Here's how a veteran player approaches this tight 6x6 layout to find the "Aha!" moment.

The Crucial Square: Row 2, Column 3

The solution finally explodes when you lock in Row 2, Column 3. Initially, it looks crowded with neighbors, but applying Cross-Hatching reveals the only valid number. In Row 2, we already have 4, 3, 5, 1. The missing numbers are 2 and 6. Looking at Column 3, the number 6 is already present in Row 5. By elimination, 6 cannot go in Row 2, Column 3. This forces 2 into that square. Once 2 is placed, the entire Row 2 and Column 3 become solvable, creating a cascade of Hidden Singles in the surrounding 2x3 blocks.

Technique: Cross-Hatching in 6x6

In a 6x6 grid, the blocks are 2x3. Cross-Hatching is your most aggressive tool. 1. Pick a number (e.g., 5). 2. Scan every row and column for existing 5s. 3. Mark the empty cells in the relevant blocks that are "crossed out" by these lines. 4. The one remaining cell in a block must be the 5.

For LinkedIn 6x6 Sudoku #321, apply this to 5 in the top-left block. The 5 in Row 2 and Column 4 blocks out most options, leaving only one spot for the missing 5 in that block.

Technique: Hidden Singles & The "Only Place" Rule

A Hidden Single occurs when a number can go in only one place within a row, column, or block, even if the cell has other candidates. Look at Row 3. It has 3, 6 filled. The missing numbers are 1, 2, 4, 5. Scan Column 2: It already has 3, 5. Scan Column 3: It has 2, 6 (after our Crucial Square move). Using the "Only Place" logic, 1 can only fit in Row 3, Column 4 because all other columns in that row are blocked by 1 in other rows. Pinning this 1 makes the next 4 and 5 obvious.

How the Final Answer Was Derived

The breakthrough wasn't luck; it was the realization that Row 2, Column 3 was the bottleneck.

• Step 1: Use Cross-Hatching on 2 and 6 in Row 2.
• Step 2: Eliminate 6 due to the vertical block, forcing 2 (The Crucial Square).
• Step 3: This 2 unlocks Row 3, Column 2 via Hidden Singles.
• Step 4: The remaining grid fills rapidly with Naked Singles once the top-left cluster is resolved.