LinkedIn 6x6 Sudoku #218 Pro-Tips Speed-Run

LinkedIn 6x6 Sudoku #218: Pro-Tips Speed-Run Guide

Grid hits you with scattered givens: row 1 has 3 in column 3, 1 in 5; row 2 packs 5 in 4; row 3 drops 1 in 2, 4 in 4, 6 in 6. Rows 4-6 layer in 2,3,5 mid-pack, 6 early, 4 late. This setup screams scan by number from jump—6x6 logic chains snap quick if you hit the right pivots.

Opening Salvo: Cross-Hatching for Quick Wins

Start scanning 2. Row 4 owns it in column 3—can't hit column 3's row 1 3 or row 3 empty. Cross-hatch: eliminate 2 from column 3 possibles in rows 2,5,6. Row 5 blocks it with 6 nearby? Nah, but box 4 (rows 4-6, cols 1-3) forces 2 out of row 6 col 3. Boom, row 2 col 3 must be 2 via box 2 elimination. Pencil that: row 2 now 2 in col 3, 5 in 4.

Chain it. Now hunt 4: row 1 col 1 screams candidate after givens clear junk. Cross-hatch column 1—no 4 in row 3 col 2 1, row 5 col 2 6. Box 1 pins it row 1 col 1. Place it. Row 1 unlocks: col 2 scans to 5 (only spot left post-3,1).

Crucial Square: Row 3 Column 5 – The Deadlock Breaker

Here’s the crucial square: row 3, column 5. Empty at start, but after early fills (row 1: 4,5,3,_,1,_; row 2 partial), scan 2 in box 2. Givens pin 1,4,6 nearby—cross-hatch rows/cols, hidden single emerges: only row 3 col 5 fits 2 in box. Slam it in.

Why crucial? This cracks difficult row 3 wide open. Box 2 now demands 3,5 left. Column 5 blocks with row 1 1, row 4 5 incoming—row 3 col 5=2 forces row 3 col 1 to 3 (hidden single, can't peek row 4 col 1). Row 3 col 6? Box forces 5? Wait, propagate: now row 3 reads 3,1,_,4,2,6? No—col 3 empty, but 5 slots via elimination. Aha! Entire top cascades: box 3 fills row 1 col 6=2, row 2 col 6=3, etc.

Hidden Singles & Propagation: Mid-Game Accelerator

Post-crucial square, hidden singles dominate 6x6—fewer cells mean singles hide less. Example: box 4 after row 4 givens ( _,_,2,3,5,_ ). Scan 1: row 3 col 6 6 blocks, column 6 row 5 4—only row 6 col 6 fits 1 in box? Nah, sharpen: row 4 col 6 empty, but column 4 3 pins it row 6 col 4=1 first (hidden pair elsewhere clears). Pencil marks shrink: row 6 col 1=2 via box 4 scan.

Pro-move: after each placement, re-scan the number in its box/row/col. Row 5 col 3 cracks to 1—column 3 now full-ish, forces row 4 col 1=6? Chain reaction: bottom boxes fill symmetric, top mirrors down.

Final Push: Box Elimination & Speed Tricks

Boxes 5-6 tangle late—scan 3 by number. Row 6 col 2 pins after row 1 col 2 5, row 5 col 2 6. Elimination: row 6 col 3=4 (only left). Last row 6 col 5=6, col 6=5? Backfill: entire grid snaps as singles cascade up columns.

How I got the final answer: nailed crucial row 3 col 5=2 via cross-hatch on 2 in box 2, propagated hidden singles row-by-row. Total speed-run: under 90 seconds spotting that pivot. Your edge: always hit constrained boxes first, scan digits 1-3 early—they cluster givens here. Practice this on #218, feel the grid break.