01
Does Clue Count Predict Difficulty? Our 512-Puzzle Catalog
Medium and Hard both have a median of 25 clues in our catalog. Explore the full distributions, compare two puzzles and understand the limits of solver-rated difficulty.
Sudoku Slate research
Sudoku difficulty and solving techniques
Clue counts, solving steps and worked examples from our 512-puzzle catalog.
512
puzzles in one frozen catalog
4 × 128
puzzles per grade
5
solving techniques
Read the study →
02
Where Do Sudoku Singles Stop Working? A 512-Puzzle Study
Our Hard puzzles reach their first elimination with a median of 39 empty cells. Inspect the exact bottleneck, follow a deduction and see what this measure does and does not mean.
Research data
Download puzzle records, summary tables and the source code used for these studies.