Reddit-style help example
Next logical step: Locked Candidates removes 4 from column 9
This page is prepared as a visual detail link for a Sudoku help reply. It explains one next logical move rather than dumping the full solution.
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Visual example
Next logical step: Locked Candidates removes 4 from column 9
Look at the middle-right 3×3 box and column 9. All possible 4s inside that box sit in column 9.
How to read this visual
Look at the middle-right 3×3 box and column 9. All possible 4s inside that box sit in column 9.
- 1 Find the pattern In the middle-right box, candidate 4 is locked into r4c9, r5c9, and r6c9. Whichever one becomes 4, the box will place its 4 somewhere in column 9.
- 2 Use the restriction Since the box already claims column 9 for digit 4, no cell outside that box in column 9 can keep candidate 4. Cross out 4 from r3c9.
- 3 Keep practicing For locked candidates, scan a box for a digit whose candidates all line up in one row or column. Then remove that digit from the same line outside the box.
Result: Remove 4 from r3c9.
Next logical step
Locked Candidates
Remove 4 from r3c9.
Why this works
- Focus: Look at the middle-right 3×3 box and column 9. All possible 4s inside that box sit in column 9.
- Pattern: In the middle-right box, candidate 4 is locked into r4c9, r5c9, and r6c9. Whichever one becomes 4, the box will place its 4 somewhere in column 9.
- Elimination: Since the box already claims column 9 for digit 4, no cell outside that box in column 9 can keep candidate 4. Cross out 4 from r3c9.
- Practice: For locked candidates, scan a box for a digit whose candidates all line up in one row or column. Then remove that digit from the same line outside the box.
Continue learning
Want hints like this while solving? Sudoku Coach teaches the technique behind each next move instead of only revealing the answer.
Learn the underlying method in the Locked Candidates guide.
App import is intentionally not part of this V1. This page is site-only; future versions can add Universal Link puzzle import.
Reddit reply draft for human review
Use only after checking subreddit rules and confirming the visual explanation matches the posted screenshot. The reply includes a useful answer before the link and discloses affiliation.
In the middle-right box, all the possible 4s are in column 9: r4c9, r5c9, and r6c9. That locks the box's 4 into column 9, so 4 can be removed from r3c9 outside the box. I made a visual explanation here: https://sudoku.franklab.us/reddit-puzzles/demo-locked-candidates-column-9/ Disclosure: I am affiliated with Sudoku Coach; the page is meant to explain the logic visually.