Techniques › Simple Colouring › Practice
Practise the Simple Colouring
Follow one digit's forced chain through the grid in two alternating colours.
8 real positions, each taken from an actual puzzle at the moment this was the cheapest move available. Two steps: find the cells that form the pattern, then find the candidate it rules out. A near miss tells you how many you had right, so getting it wrong is worth something.
| 5 | 1 | 2 | 4 | 6 | 7 | 9 | 3 | 8 |
| 4 | 7 | 3 | 8 | 1 | 9 | 2 | 5 | 6 |
| 8 | 9 | 6 | 5 | 3 | 2 | 1 | 4 | 7 |
| 9 | 2 | 8 | 3 | 5 | 1 | 7 | 6 | 4 |
| 3 | 4 | 17 | 6 | 27 | 8 | 5 | 12 | 9 |
| 17 | 6 | 5 | 27 | 9 | 4 | 8 | 12 | 3 |
| 127 | 3 | 17 | 27 | 8 | 6 | 4 | 9 | 5 |
| 6 | 8 | 9 | 1 | 4 | 5 | 3 | 7 | 2 |
| 27 | 5 | 4 | 9 | 27 | 3 | 6 | 8 | 1 |
How to spot it
Choose a digit with many conjugate pairs. Start anywhere, colour alternately, and watch for two cells of one colour landing in the same house.
Full explanation on the Simple Colouring reference page.