This command opens the Check Equivalency Dialog Box (pictured below).
If two puzzles are 100% equivalent, they are isomorphs of eachother. If they are 0% equivalent, then they have no significant similarity.
Puzzle 1 & 2:
Enter the paths to the two saved Sudoku files that you want to check in these spaces. Note: These puzzles must be previously saved! Use the Save or Save as command to save a puzzle. Puzzle 1 will be automatically populated with the current puzzle, but if it hasn�t been recently saved, the analysis will be performed on the most recently saved version.
Click the Check button when you�re ready to perform the analysis. The checking process may take several seconds, or even minutes depending on the speed of your processor and the nature of the puzzles.
The algorithm for checking equivalency works like this. Sudoku Snake runs through all the possible isomorphs and for each one counts how many givens are the exact same number in the exact same cell for each puzzle. It also averages how many givens are in each puzzle. Now, since you can rearrange the 9 different rows or columns individually to match at least one value from the other puzzle, Sudoku Snake subtracts 9 from the number of givens that are exactly the same, and also subtracts 9 from the average count of givens. Thus, any number above 9 of exact matches is considered significant equivalency. The number of similarities divided by the average number of givens (both with 9 subtracted) is the percent equivalency.
Most puzzles are about 20% equivalent with most other puzzles.