Magic Numbers Guide For Channel F

Strategy

For Mind Reader, spread out your numbers on the first guess to get a feel for which digits are present. If you have any hits or misplaced digits, you can then work to narrow down which one is correct or get one in the wrong spot to the correct spot. Don't forget that the same digit can be in the number more than once. For Nim, you want to look at the number in each stack as a collection of its binary digits. For example, if you are looking at a stack of 15, think of it as a collection of 8,4,2,and 1. For each item in this collection, you want to pair it up with a matching item in another stack's collection to cancel it out. If you had a 5 stack (4 and 1) and a 10 stack (8 and 2), these would cancel out the 15 leaving what is known as a nim sum of 0. If everything cancels out in this way at the start of your turn, the computer has you on the ropes. If there is an imbalance, you are in the driver's seat and must find what you can remove to restore the balance.