I’ve been involved in a couple of math trades recently, and I felt pretty good about the outcomes. A math trade is sometimes called a mathematical no-risk trade list. It is a method of maximizing the number of trades between large groups of people.
Let’s say that I have an extra copy of California and I ask Joe if he will trade it for his copy of Ticket to Ride: The Card Game. He’s not interested because he’s already got a copy of California, but he would trade his copy of Ticket to Ride: The Card Game with William for his copy of GiftTRAP. William doesn’t want Ticket to Ride: The Card Game but he would like my copy of California. So obviously, the solution is that I give my game to William, who gives me his game, and then I give the game I just got from William to Joe who gives me the game I want. Everyone’s happy.
A math trade is like that but with a hundred people. The exchange is so complex that it requires a computer algorithm to successfully calculate all of the required trades.
If you are a BGG regular, you should give a math trade a try.