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Module 7 · Advanced PracticeLesson 28 of 28

Advanced Mixed Practice

Select and apply advanced techniques from board structure without being told the technique name.

Outcome

You can inspect an unlabeled candidate grid, choose an appropriate Advanced search lens, prove the deduction, and return to simpler solving instead of forcing named patterns.

Intro copy

Advanced solving is not:

“Which hard technique have I not tried yet?”

It is:

“What structure is this candidate grid giving me?”

This checkpoint mixes Fish, Wings, single-digit link patterns, Chains, Coloring, and optional uniqueness.

Technique names appear after a correct deduction unless the learner requests a deeper hint.

Search Lens 1 — One digit

Prompt:

The candidate grid looks sparse for one digit. What family should you inspect?

Core lesson targets:

  • X-Wing;
  • Swordfish;
  • Skyscraper;
  • Two-String Kite.

Guide-only extensions such as Simple Coloring and X-Chain may be explored separately, but they are not required for this checkpoint.

Tools:

  • candidate filter;
  • Strong-Link overlay as optional hint.

Search Lens 2 — Bivalue cells

Prompt:

Several cells have exactly two candidates. What relationships could matter?

Useful targets:

  • XY-Wing;
  • W-Wing;
  • XY-Chain.

XYZ-Wing can enter when a related trivalue pivot appears.

Search Lens 3 — Strong-Link network

Prompt:

One digit has several conjugate pairs. What can you inspect?

Useful targets:

  • Skyscraper;
  • Kite;
  • Coloring;
  • X-Chain;
  • W-Wing connections.

Search Lens 4 — Geometry + uniqueness

Available only when:

unique solution verified

Prompt:

Do repeated bivalue candidates form a valid 2-row / 2-column / 2-box rectangle?

Useful target:

  • Unique Rectangle Type 1.

If uniqueness is disabled, this lens does not appear.

Set A — Family recognition

Eight mini-states.

Learner labels only the search family, not the exact technique:

  • Fish;
  • Wing/bivalue;
  • one-digit link pattern;
  • Chain/Coloring;
  • uniqueness;
  • simpler deduction first.

This trains navigation through the technique library.

Set B — Exact deduction

Six states:

  1. X-Wing;
  2. Swordfish;
  3. XY-Wing;
  4. XYZ-Wing;
  5. Skyscraper or Two-String Kite;
  6. W-Wing.

Prompt always begins:

Find one logically forced elimination.

After success, UI reveals:

  • technique name;
  • one-sentence proof;
  • link to full Guide.

Set C — False advanced patterns

Include:

  • X-Wing rectangle with extra source candidate;
  • XY-Wing with mismatched Z;
  • W-Wing with Weak-only bridge;
  • Skyscraper with source row containing a third candidate;
  • invalid four-box Unique Rectangle.

Prompt:

Is this named pattern valid?

Then:

Which condition fails?

Set D — Simplest useful move

Show a board containing:

  • one valid advanced pattern;
  • one Hidden Single.

Prompt:

What move should you make first?

Accept the Hidden Single.

Second example:

  • valid Swordfish;
  • simple Locked Candidates elimination that opens the same area.

Prefer the simpler move.

Advanced mastery includes not using advanced logic unnecessarily.

Set E — Follow the consequences

Sequence 1

X-Wing
↓
candidate elimination
↓
Hidden Single
↓
Locked Candidates
↓
Naked Single

Sequence 2

W-Wing
↓
candidate elimination
↓
Naked Pair
↓
two Singles

Sequence 3

Two-String Kite
↓
candidate removed
↓
Pointing
↓
placement

The learner performs the whole cascade, not only the “advanced” first move.

Hint ladder

Hint 1 — Search mode

Follow one digit.

or:

Inspect bivalue cells.

Hint 2 — Area / candidate

Highlight a useful unit, digit, or candidate subset.

Hint 3 — Family

Fish.
Wing.
Strong-Link pattern.

Hint 4 — Structural clue

Two rows use the same two cover columns.

Hint 5 — Technique

X-Wing.

Hint 6 — Visual proof

Highlight exact source/links/targets.

The first hint should never simply name the technique.

Final guided puzzle segment

Construction requirements:

  • verified unique classic puzzle;
  • 12–25 controlled actions;
  • at least three Advanced deductions;
  • at least three technique families;
  • simpler deductions between Advanced steps;
  • no uniqueness step unless enabled;
  • all candidate states solver-validated;
  • human-style analyzer confirms every intended move;
  • equivalent valid simpler paths reviewed before publication.

Potential structure:

X-Wing
↓
Hidden Single
↓
Locked Candidates
↓
XY-Wing
↓
Singles
↓
Skyscraper or W-Wing
↓
cleanup

The exact board should be selected only after Sudoku Core can validate the intended path.

Completion criteria

Learner must complete:

  • family recognition set;
  • exact-deduction set;
  • false-pattern set;
  • simplest-useful-move set;
  • one consequence cascade;
  • final guided segment.

Final attempts should not require exact-technique hints.

Completion copy

You now have a working solving system from the basic rules through Advanced candidate patterns and introductory Chains.
Expert techniques can extend the same ideas later, but they are not required to complete the current Sudoku learning path.

Actions:

What can come next?

Potential Learn/Expert expansion:

  • dedicated Simple Coloring practice;
  • dedicated X-Chain / XY-Chain lessons;
  • Jellyfish;
  • Finned Fish;
  • Empty Rectangle;
  • deeper Unique Rectangle types;
  • BUG+1;
  • full AICs;
  • ALS techniques;
  • Forcing Chains / Nets.

These should be added when VeyraPlay can generate, validate, visualize, and teach them properly — not merely to make the technique list longer.

Reference

Use Advanced Sudoku Strategies when you want the search map, and individual Technique Guides when you want a complete proof.