| This technique is very useful in harder games to get the game going (but remember it might also be essential at any point in the game). |
Look for a pair of numbers to start with. Then look for any other occurrences of the same number in the same row or column as the pair, and paint (set) them. |
| Any pair of numbers indicates that one must be painted, and the other must be circled. It really doesn't matter whether we know which is which at this time, but what we can deduce is that any other occurrence of the same number in the row or column where the pair was found, it cannot possibly be circled. |
