# Mini Cactpot

Click on a square to enter a digit.

##### About

Mini Cactpot is a scratchcard lottery where each of the numbers \(1\) through \(9\) are hidden in a \(3 \times 3\) grid. One cell is initially revealed, and after selecting 3 more to uncover one at a time, you may select any row, column, or diagonal. The sum of your selected line determines how much MGP you win.

Sum | MGP | Sum | MGP |
---|---|---|---|

6 | 10,000 | 16 | 72 |

7 | 36 | 17 | 180 |

8 | 720 | 18 | 119 |

9 | 360 | 19 | 36 |

10 | 80 | 20 | 306 |

11 | 252 | 21 | 1,080 |

12 | 108 | 22 | 144 |

13 | 72 | 23 | 1,800 |

14 | 54 | 24 | 3,600 |

15 | 180 |

This calculator works by computing the expected value of selecting any line or cell. A strategy that doesn’t involve heavy computation is to first reveal a “Y” shape on the board.

Next, select a line as follows:

- If a line can be the 123 line, select it; otherwise
- if a line can be the 789 line, select it; otherwise
- select whatever line can have the biggest sum (not payout).

This strategy gives an expected value of 1259, whereas perfect play gives 1484. Note that in steps 1 and 2, if a 123 or 789 line exists, you will always select it without ambiguity. In step 3, you may have to guess which lines may have a large sum.