Please view comments to see how it is not a duplicate.... I am looking at it from a CPU perspective.
If there are 23 coins that are on a screen, and there are two players and you get to pick if you go first or second, how can you guarantee that you will not get stuck with picking the last coin? Basically, the objective is to force the other person to pick the last coin.
every turn you can pick 1 or 2 coins
I think half of the answer is in how many coins to pick in the first turn.