N Back - A Memory Brain Game

You are shown a stream of cards, and try to indicate when the same card you see also is the same card you saw N cards ago.

The game is pretty simply, you're shown a bunch of cards, your job is to hit match if the card you is the same card you saw N spots ago. If the value of N is 1, that means that if I show you a card, and the previous card was the same card, then its considered a match. If N is 2, then if I show you a card, and the card that came two spots before the current one is the same, then its considered a match.