LinkedIn 6x6 Sudoku #236 Pro-Tips Speed-Run

LinkedIn 6x6 Sudoku #236: Speed-Run Breakdown

Grid hits you with a diagonal staircase top-left to bottom-right: 1-2-3 across rows 1-3 in columns 1-3, 4-5-6 filling the rest. Bottom starts clean with 1-2-3 in column 4, 6-5-4 in column 6. This 6x6 beast looks symmetric but hides nasty blocks. Veteran move: pencilmark empties fast, then cross-hatch like a laser.

Pro-Tip 1: Cross-Hatching the Staircase

Start with 1. Cross-hatch row 1 (hits col1), row 4 (hits col4). In top-right 2x3 block (rows1-2, cols4-6), scan columns: col5 empty for 1, col6 blocked by nothing yet. But row2 col1 has 2, so row2 possibilities narrow. Draw mental lines through givens: eliminates 1 from row1 col2-6 except where boxes force it. Row1: 6 slots into col2 by box exclusion alone. Boom, first placement.

• Repeat for 2: row2 col1 given, cross-hatch eliminates row2 col4-6 except col5 possible.
• 3 follows: row3 locks similar pattern.

This fills top band progressively. 6x6 shrinks the search space; boxes are 2x3, so fewer cells per unit means quicker eliminations.

Pro-Tip 2: Hidden Singles in the Bottom Band

Bottom rows 4-6, column4 has 1-2-3 stacked. Cross-hatch 4 in row6 col6 given. Look row4: possibles in col1-3,5. But column1 scans empty rows4-6; hidden single emerges in row4 col1 for 4 because box1 (rows4-6,cols1-3) blocks elsewhere via column6's 6-5-4.

Pencilmarks reveal: row4 col2 can't take 4 (row6 blocks), col3 blocked by pattern. Only row4 col1 holds 4 in that column and box. Place it. Chain reaction: row5 col1 gets 6 as hidden single next.

Crucial Square: Row3 Column2 - The Crack Point

Grid stalls mid-solve around top band fills. Row3 col2 is your crucial square. After top rows partial fill (1s,2s,3s shift), cross-hatch 1 in row3 box: column2 only spot left unmarked in row3 and right-top box. Hidden single: 1 locks there.

Why crucial? Unlocks row3 col6 (2 naked single), cascades to column3 row1 (5), then row1 col4 (5). Suddenly middle band cracks wide. From stall to speed-run finish in seconds.

Difficult Row: Row1 - Hidden Pairs Lurk

Row1 fights back early. Empties: col2,4,5,6. Cross-hatch reveals 6 col2 (box forces), 5 col4 (column4 bottom blocks). Left: col5-6 hold 2,3 hidden pair. Eliminate extras via boxes. Row1 done, top cascades.

Speed-Run Finish: Chain the Singles

Post-crucial square: row4 col5 3 hidden (column5 scans), row5 col2 4 follows. Column2 fills bottom-up. Last push: row6 col3 1 naked after eliminations. Full grid snaps in. Total time under 90 seconds with pencilmarks.

Key: 6x6 rewards aggressive cross-hatching per box. Hidden singles hide in 2x3 constraints. Practice this pattern; next #236 clone falls faster.