LinkedIn 6x6 Sudoku #440: Pro-Tips Speed Run

The Speed-Run Plan

LinkedIn 6x6 Sudoku #440 uses six 2-by-3 boxes, with every row, column, and box containing the digits 1 through 6 exactly once. This grid rewards disciplined scanning rather than guesswork.

Start with the givens in the center. The middle boxes already contain several linked pairs: 2, 3 near the top and 4, 5 below. Those numbers restrict their columns sharply, so do not treat the clues as isolated facts. Read them across rows, down columns, and through their boxes.

Pro-Tips for #440

1. Cross-hatch the crowded columns

When a box needs a digit, eliminate positions using the matching rows and columns. For example, the 2 in the upper-middle area removes 2 from competing cells in its column and box. Repeat this with 3 and 4. In a 6x6 grid, each elimination has more impact because there are fewer candidates to begin with.

2. Hunt hidden singles, not just open ones

A hidden single appears when a digit has only one legal location in a row, column, or box, even if that cell still appears to have several candidates. The lower-middle box is especially productive: its clues 4, 5, and 1 force the remaining digits into narrow lanes.

3. Use the top-left box as a relay

Once the center tells you where 2 and 3 can go, feed those restrictions into the upper-left box. That box then resolves a row position, which sends a new exclusion into the left-hand columns. This is the cleanest chain in the puzzle: center pressure, left-box placement, then column cleanup.

The Crucial Square

The breakthrough comes in the fourth row, third column: the crucial square. Its row already contains 4 and 1, while its column contains the upper 3 and the lower constraints created by the central boxes. Cross-hatching leaves only 5.

That placement is the hinge. The fourth row now needs 2, 3, and 6, and the surrounding columns restrict those digits to distinct positions. A hidden single follows in the same row, then the bottom-middle box begins to collapse.

Finishing the Grid

After the crucial 5, keep the scan local. Complete the affected box, check its three columns, and immediately revisit the bottom rows. Avoid jumping around the board; every confirmed digit should trigger a short three-way check:

• What does it remove from its row?
• What does it remove from its column?
• What does it remove from its 2-by-3 box?

That rhythm produces the final arrangement:

5 1 6 3 2 4
4 2 3 6 5 1
1 3 4 2 6 5
2 6 5 4 1 3
3 5 2 1 4 6
6 4 1 5 3 2

The lesson from #440 is simple: when a 6x6 puzzle feels stalled, stop searching for a dramatic single. Find the digit that is boxed in by several ordinary restrictions, then let that placement do the heavy lifting.