LinkedIn Sudoku #436: 6x6 Speed-Run Guide

Pro-Tips for LinkedIn Sudoku #436

This 6x6 layout uses six digits, with each row, column, and 2x3 box containing 1 through 6 exactly once. The fastest route is not random scanning. It is controlled pressure on the boxes.

Start with the givens

The opening pattern gives the top row 1, 2, 3 in consecutive positions, while the left side supplies 2, 3, 5 down the grid. Mark the missing values mentally, then use the 2x3 boxes to restrict them immediately.

In the upper-left box, the missing digits are 4, 5, 6. Column pressure removes 5 and 6 from the first row's open positions, forcing the row's remaining structure. This is classic cross-hatching: a digit's row and column restrictions narrow its box until only one landing spot survives.

The crucial square

The key breakthrough sits in the lower-right box, where the givens already show 2 and the surrounding columns have eliminated most alternatives. The square at row 6, column 5 becomes a crucial square: it can take only 2, which locks the final pair in that row and sends a clean cascade upward through column 5.

Once column 5 settles, the third and fourth rows stop behaving like open searches. Their missing digits are reduced to compact pairs, and the boxes decide which member belongs where. Do not guess here. Let the box boundaries do the work.

Hidden singles finish the run

The middle boxes contain the most useful hidden singles. A digit may have several empty squares available in its row, but only one of those squares remains legal inside the box. In this grid, that distinction is what places the missing values in the central rows and exposes the last entries in the left-hand columns.

A good speed-run habit is to scan each box for one digit at a time, especially 1, 4, and 6. Their placements quickly tighten the rows containing the fewest givens. Every confirmed value should be checked against its row, column, and box before moving on.

The final pattern

With the crucial square fixed and the hidden singles resolved, the rows complete in sequence:

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

The finish is fully forced. Each row contains 1 through 6, every column does the same, and all six 2x3 boxes validate. The lesson from #436 is simple: establish the box structure first, identify the one square with a single legal value, then let the resulting chain do the heavy lifting.