LinkedIn 6x6 Sudoku #253 Pro-Tips Speed-Run

LinkedIn 6x6 Sudoku #253: Speed-Run Breakdown

Grab this 6x6 grid and let's blitz it. Numbers 1-6, standard rows, columns, 2x3 boxes. Start with quick scans for naked singles, then layer in cross-hatching to expose hidden ones. This puzzle fights back early but cracks wide open at one key spot.

Opening Moves: Scan and Cross-Hatch Ruthlessly

Eye row 1: 2 in col2, 6 col3, 3 col4, 5 col5. Col1 empty, col6 empty. Cross-hatch for 1 across the top row and box1 (rows1-3, cols1-3). 1 sits in row2 col1 and row3 col2. Strike those from col1 possibilities in box1: only row1 col1 left for 1. Boom, place 1 at (1,1).

Chain it. Now row1 col6: scan box2 (rows1-3, cols4-6). 3,5,6 block out; row1 has 2,6,3,5; col6 has 1 below. 4 slots in (1,6). Row1 done.

Pro-Tip: Cross-Hatching in 6x6

Pick a number, say 4. Mark rows/cols with 4s mentally. In a box missing 4, eliminate crossed cells. This grid's tight 2x3 boxes make it sniper-precise. Repeat for 2: row6 col3 has it, row3 col2 blocks row-box overlaps. Hidden spots pop fast.

The Difficult Row: Row 5 Stalls Hard

Row5: 6 col2, 4 col5. Empties everywhere else. Early fills leave it tangled: possibles cluster 1,2,3,5 across cols1,3,4,6. No naked singles. Columns clash, boxes overlap messily. This is your Crucial Square: cell (5,4).

Hidden Single Unlock at (5,4)

After initial chain (1,1=1 sparks row2 col2=4 via box1 scan; cascades to row2 col3=5, etc.), pencilmark row5. For 2 in row5: col3 has row6 2, so no (5,3). Box3 (rows4-6, cols4-6) sees 2 in row6 col3 (box4 spillover). Col4 possibles shrink.

Cross-hatch 2 in box2 (rows1-3, cols4-6): lands row3 col6=2 after elims. Propagate down. Now row5: 2 can only breathe in (5,4). Other spots blocked by row4 col6=2 (from earlier naked single). Hidden single: 2 at (5,4). Pencilmarks vanish elsewhere in row5 col4.

Aha! The Crack Widens

Drop 2 at (5,4). Row5 lights up: col1 scans to 5 (only spot left post-box4). Col3: 1 via hidden single in box3. Col6: 3. Boom, row5: 5,6,1,2,4,3. Full house triggers neighbors.

Row4 col1=6 (box1 forces). Row6 col1=4. Col1 finishes: row3 col1=2. Snowballs through row3=2,1,3,4,6,5. Rest naked singles cascade clean.

Speed-Run Pro-Tips for #253

• Target Almost-Full Units: Row2 starts with five empties but givens pin hidden singles fast. Hit these first.
• Box-by-Box Cross-Hatch: 6x6 means fewer cells; cycle numbers 1-3 in top boxes, 4-6 bottom. Misses fewer.
• Pencil Early, Chase Chains: Fill (1,1)=1, immediate row1 col6=4. Don't pause; one placement often gifts two more.
• Crucial Square Drill: When stalled, list candidates per cell in the tough unit. Row5 col4 screamed hidden 2 once priors cleared.
• Full House Trigger: Row5 completion nukes row4/6 singles. Always ripple after a row/box fills.

Sub-2-minute solve with practice. Row5's (5,4) was the linchpin; master spotting those hidden singles via cross-hatch, and grids like #253 fold quick.