GridMew1Check region A
region A has only one remaining candidate: row 1, column 5. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 1. Place one cat, then exclude 11 other cells.Two singletons release the bottom-right region
Original puzzle gm-8-0055
By GridMew · Published 15 October 2026 · Updated 16 October 2026
8 × 8 practice
Read the starting position, follow the deductions, and check the move that is easy to misread.
Puzzle board · starting state
How to approach this board
Coordinates such as r2c3 mean row 2, column 3. Count rows from the top and columns from the left.
A at r1c5 and F at r6c7 each force a cat. Use both before choosing among H’s many lower cells. Their row, column and neighborhood effects reduce H to r8c6.
8×8 · 1 fixed cats · 7 explained deductions. Region sizes: A: 1 · B: 14 · C: 4 · D: 20 · E: 13 · F: 1 · G: 2 · H: 9.
A deduction worth checking
The H cat removes r4c6 through column 6, well above its local neighborhood. That long effect matters when the solve returns to the upper rows.
A move to double-check · r4c6
r4c6 is not safe just because it is four rows above r8c6. Both would occupy column 6, which admits one cat.
Green marks the cell being discussed, not a cat to place. This is the position before step 3; compare the deduction below.
Read the starting board as text
Each line is one row, left to right. Matching letters belong to the same connected region.
B B B B A D D D B B B B B D D D B B B C C D D D B B E C C D D D E E E E D D D D E E E E H H F D G E E H H H D D G E E H H H H D
Fixed cats: row 3, column 4. One cat is required in each row, column and region.
Step-by-step walkthrough
2Check region F
region F has only one remaining candidate: row 6, column 7. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 2. Place one cat, then exclude 14 other cells.3Check region H
region H has only one remaining candidate: row 8, column 6. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 3. Place one cat, then exclude 5 other cells.4Check region G
region G has only one remaining candidate: row 7, column 1. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 4. Place one cat, then exclude 5 other cells.5Check column 3
column 3 has only one remaining candidate: row 5, column 3. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 5. Place one cat, then exclude 2 other cells.6Check row 4
row 4 has only one remaining candidate: row 4, column 8. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 6. Place one cat, then exclude 1 other cells.7Check row 2
row 2 has only one remaining candidate: row 2, column 2. Every other cell is excluded by earlier placements or deductions. Place the cat here.
Before step 7. Place one cat, then exclude 0 other cells.Show solution · reveals all cat positions
The final cats satisfy every row, column and region quota, with no edge or corner contact.
Cat positions: r1c5, r2c2, r3c4, r4c8, r5c3, r6c7, r7c1, r8c6.
Try another puzzle
Two singleton regions steer a seven-placement finish
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