Snyder vs Full Notation
Choosing the Right Pencil Mark Strategy
Every serious Sudoku solver faces this choice: Snyder Notation or Full Candidate Notation? The answer isn't one-size-fits-all — each method has strengths, and the best solvers know when to use which. This guide will help you decide.
- Snyder: Mark only bi-value candidates (2 possible cells per box) — fast, clean, great for easy-medium puzzles
- Full Notation: Mark all candidates in every cell — thorough, required for advanced techniques
- Best approach: Start with Snyder, switch to full notation when stuck
Quick Comparison
| Aspect | Snyder Notation | Full Notation |
|---|---|---|
| What you mark | Only bi-value candidates (2 cells per box) | All possible candidates in every cell |
| Grid clutter | 🟢 Minimal | 🔴 High |
| Setup time | 🟢 Fast (mark as you scan) | 🔴 Slow (must fill entire grid) |
| Pattern visibility | 🟢 Excellent for pairs/pointing | 🟡 Required for chains/fish |
| Best difficulty | Easy → Medium | Hard → Expert |
| Speed solving | 🟢 Preferred by competitors | 🔴 Too slow for timed solves |
| Learning curve | 🟢 Easy to learn | 🟡 More to track mentally |
| Technique support | Basic + intermediate | All techniques |
What is Snyder Notation?
Snyder Notation, developed by 4× World Sudoku Champion Thomas Snyder, is a minimalist marking system: you only write candidates when a number has exactly two possible cells in a box.
This means most cells stay empty or have just 1-2 small corner marks. The grid stays clean, patterns pop out, and you can solve faster. (See our complete guide for the full technique.)
- • Very fast to apply
- • Grid stays readable
- • Pointing pairs immediately visible
- • Less cognitive load
- • Perfect for speed solving
- • Can't see all candidates
- • Misses 3+ option situations
- • Insufficient for X-Wing, Swordfish
- • Won't solve expert puzzles alone
What is Full Candidate Notation?
Full Candidate Notation (also called "pencil marks" or "candidates") means writing every possible number in each unsolved cell. If a cell could contain 1, 4, 7, or 9, you write all four.
This gives you complete information but creates a visually dense grid. Most cells will have 3-6 candidates, making patterns harder to spot — but it's the only way to use advanced techniques.
- • Complete candidate information
- • Enables all advanced techniques
- • Required for X-Wing, Swordfish, chains
- • Can solve any puzzle
- • Clear elimination tracking
- • Slow to set up
- • Visually overwhelming
- • Hard to spot basic patterns
- • Higher error rate
- • Tedious maintenance
Detailed Comparison
Visual Clutter
The most obvious difference is how the grid looks:
Snyder Notation
Typical cell might show:
Most cells empty, some with 1-2 corner marks
Full Notation
Typical cell might show:
Most cells packed with 3-6 candidates
Technique Support
| Technique | Snyder | Full |
|---|---|---|
| Naked Singles | ✅ Yes | ✅ Yes |
| Hidden Singles | ✅ Yes | ✅ Yes |
| Pointing Pairs | ✅ Excellent | ✅ Yes |
| Naked Pairs/Triples | ⚠️ Partial | ✅ Yes |
| Hidden Pairs | ✅ Good | ✅ Yes |
| X-Wing | ❌ No | ✅ Required |
| Swordfish | ❌ No | ✅ Required |
| XY-Chains | ❌ No | ✅ Required |
| Coloring | ❌ No | ✅ Required |
Speed Comparison
For competitive solving, speed matters enormously:
Time Investment
On an easy puzzle, you might solve it entirely in the time it takes to write full candidates.
When to Use Snyder Notation
- Playing easy or medium difficulty puzzles
- Speed solving or competing
- Boxes have 5+ givens already
- You want a clean, readable grid
- Starting any puzzle (as initial strategy)
Snyder is ideal for 70-80% of solving time on most puzzles. It handles all basic and many intermediate techniques while keeping your grid clean enough to actually see patterns.
When to Use Full Notation
- Snyder marks aren't revealing new moves
- You suspect you need X-Wing, Swordfish, or chains
- The puzzle is rated "Hard" or "Expert"
- You need to track complex eliminations
- Learning advanced techniques
Think of full notation as a power tool — you don't need it for every job, but when you do need it, nothing else will work.
The Hybrid Approach (Recommended)
The best solvers don't choose one method exclusively — they start with Snyder and transition to full notation when needed. This gives you the best of both worlds:
Our Recommendation
The Verdict
Learn Snyder first. It's faster, cleaner, and sufficient for most puzzles. Master the hybrid approach so you can transition to full notation when a puzzle demands it.
Ready to Practice?
Try both notation styles on our free puzzles. Minimal Sudoku supports corner marks (Snyder) and center marks (full notation).
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