What are the most advanced sudoku techniques?

X-Wing, Swordfish, XY-Wing and simple coloring are the core advanced patterns. They eliminate candidates that scanning, pairs and triples can't reach — and they still solve the puzzle with pure logic, no guessing.

When do I need advanced techniques?

On expert and evil puzzles, where few clues mean the easy placements run out fast. Once pairs and triples stop making progress, X-Wing and friends clear the candidates that unlock the rest of the grid.

Is the X-Wing hard to learn?

The pattern is simpler than it looks: a candidate locked to the same two columns in two rows. Once you can spot that shape, the eliminations follow. Our printable shows it on a real grid, and the wiki has the full walkthrough.

Do advanced puzzles ever need guessing?

No. A proper sudoku always has exactly one solution reachable by logic. Advanced techniques exist precisely so you never have to guess — they just take more patience and careful pencil marks.

Advanced Sudoku Techniques — Printable Reference

Ready for the hardest patterns? These advanced sudoku techniques clear the stubborn candidates that beat scanning and pairs. Each one comes with a real worked grid so you can recognise the shape on the board, plus a wiki link for the full method. Print the one-page reference and keep it close for your toughest grids.

A candidate locked to two cells in two rows that line up, forming an X across two columns.

X-Wing

When a candidate is pinned to the same two columns across two rows (or the same two rows across two columns), it can't appear elsewhere in those columns — clear it. Learn the X-Wing on the wiki.

Learn the X-Wing on the wiki →

A candidate spread across three rows that align in three columns, extending the X-Wing idea.

Swordfish

An X-Wing stretched to three rows and three columns: a candidate confined to three lines that line up lets you eliminate it from the crossing lines. Learn the Swordfish on the wiki.

Learn the Swordfish on the wiki →

A pivot cell and two pincer cells whose shared digit Z is removed from cells seeing both pincers.

XY-Wing

Three bi-value cells — a pivot holding X and Y, and two pincers holding X-Z and Y-Z — force the digit Z out of any cell that sees both pincers. Learn the XY-Wing on the wiki.

Learn the XY-Wing on the wiki →

A candidate chained through conjugate pairs in two colours, letting a contradiction make eliminations.

Simple coloring

Follow a single candidate through a chain of conjugate pairs, marking the two ends in alternating colours — a contradiction tells you which colour is false, so those candidates go. Learn simple coloring on the wiki.

Learn the Simple coloring on the wiki →

What's inside the printable

The expert cheat-sheet PDF puts X-Wing, Swordfish, XY-Wing and simple coloring on one printable page, each with the worked grid you see here — the kind of example article-only guides never give you. Branded, ad-free, no sign-up. Print it or save the PDF for your hardest sessions.

Print puzzles to practice

Open the printable puzzles →

Want the full lessons?

These pages are quick printable references. For the full, step-by-step teaching of any rule or technique — with interactive grids and worked walkthroughs — head to Sudoku247 Wiki. We keep it short here so you can print and go; the wiki goes deep.

Sudoku rules →

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Frequently asked questions

What are the most advanced sudoku techniques?: X-Wing, Swordfish, XY-Wing and simple coloring are the core advanced patterns. They eliminate candidates that scanning, pairs and triples can't reach — and they still solve the puzzle with pure logic, no guessing.
When do I need advanced techniques?: On expert and evil puzzles, where few clues mean the easy placements run out fast. Once pairs and triples stop making progress, X-Wing and friends clear the candidates that unlock the rest of the grid.
Is the X-Wing hard to learn?: The pattern is simpler than it looks: a candidate locked to the same two columns in two rows. Once you can spot that shape, the eliminations follow. Our printable shows it on a real grid, and the wiki has the full walkthrough.
Do advanced puzzles ever need guessing?: No. A proper sudoku always has exactly one solution reachable by logic. Advanced techniques exist precisely so you never have to guess — they just take more patience and careful pencil marks.

How to solve these

New to a technique? Read the step-by-step rules and solving guides.

Read the guide →

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