The Best Way to Organize Santa’s Secret Gift Exchange
Exchanging Secret Santa’s gifts is an easy way to make friends and coworkers in a spirit of giving without losing out on holiday expenses. Here’s the most mathematically perfect way to launch your own.
In this video from YouTube channel Numberphile, Dr. Hannah Frye explains why traditional Secret Santa doesn’t provide perfect anonymity. In fact, if you do it the old fashioned way with pieces of paper in your hat, you will often have to start over because people will often draw their own names. If you want to guarantee anonymity and make sure you only need to draw names once, here’s what Frye suggests you:
- Create a set of cards with two halves – top and bottom – for each participant. If you have 10 people, you make 10 cards.
- One half will say “You are number [#]” and the other half will say “You are buying for number [#]”. The number must be the same for both halves. If it says “You are number 1” at the top, it should say “You are buying for number 1” at the bottom.
- After you’ve made the cards, you lay them face down and shuffle them so you don’t know what order they are in.
- Now lay them side by side in a line, still face down, then cut the cards in half. Don’t reveal anything yet.
- After you have cut all the cards, slide all the top halves one by one, then combine them to make a set of new whole cards.
- Then everyone chooses one of the new whole cards.
- Finally, you make a numbered list and everyone writes their name next to their new number.
With this method, you ensure that the number at the top does not match the number at the bottom, so no one can get their own number. And since you shuffled the cards before cutting the cards, no one knows which numbers are where, which guarantees anonymity. All that’s left is to set a price cap and your Secret Santa gift exchange is ready to go.
Trouble with Secret Santa | Youtube