EXTREMEPUZZLE BOOKS

Extreme Killer Sudoku 3, puzzle 14: step-by-step solution

Step through the whole solution, or skip to the hard parts. Blue digits are placed by the walkthrough; red strike-through marks a candidate being ruled out.

Puzzle
Killer sudoku, number 14 of 150 in Extreme Killer Sudoku 3
Difficulty
Expert 3 (expert and beyond), from the opening third of the book
Key technique
Remote Pairs
Hard steps
6 of 71 steps need an advanced or expert technique

Blue digits are placed by the walkthrough. Red strike-through marks a candidate being ruled out. Cells are named by row and column: R3C5 is row 3, column 5. Arrow keys step too.

The key technique: Remote Pairs

A chain of cells that all hold the same pair alternates between the two digits. Cells that see both ends of an odd-length link cannot hold either digit.

Other advanced and expert techniques in this solve: XYZ-Wing (×2), Finned Fish, Forcing Chains, Multi-Sector Locking.

Every move above the basics is listed on the killer sudoku techniques page, each with a one-sentence explanation and worked examples from the books.

The hard steps, in text (6)
  1. Step 38 · XYZ-Wing advanced
    Rules out 4 from R3C5.
  2. Step 39 · XYZ-Wing advanced
    Rules out 8 from R8C2, R8C3, R9C4, R9C5 and 1 more.
  3. Step 40 · Multi-Sector Locking advanced
    Rules out 3 from R2C3, R3C5; 7 from R8C4; 9 from R9C3.
  4. Step 48 · Remote Pairs expert
    Rules out 7 from R3C5.
  5. Step 55 · Finned Fish expert
    Rules out 8 from R5C1.
  6. Step 56 · Forcing Chains expert
    Rules out 9 from R1C1.

The book

Volume three: 150 new killers, none repeated from books 1 or 2. No starting digits, just cages and their totals, ramping from hard to brutal.

150 new puzzles. Expert and beyond. Puzzles by M. J. Bailey. Paperback, 5 × 8 in, 196 pages, £9.99 / $11.99. Every solution in the book carries a QR code to its own walkthrough, so you can check one step without seeing the whole answer.

Try a free sample puzzle (PDF) · prints on A4 or US Letter