I signed up for it, I just post games on the website and hope for the best? 

When it goes live it will show up in Abecorn's hosted trades section. At that point you can join that trade and start listing your games. Other people, myself included, will start listing theirs. You can mark any of those other games as games you would like. After the submission period is done you will use a grid to indicate what "one for one" trades you would be willing to make. For instance you might indicate that you are willing to trade your copy of Candyland for a copy of Scrabble. After a period of time to let everyone indicate what trades they want the organizer of the trade will process the trades. That creates trade loops. For instance you might give your copy of Candyland to Alan who gives a copy of Guess Who to Bonnie who gives a copy of Monopoly to Chad who gives a copy of Scrabble to you. The physical trades will happen at the event that you signed up for.

That is a super quick rundown. Feel free to ask questions here or on the BGG thread. Math Trades are awesome!

Edit: It looks like Abecorn has a new tutorial (PDF) up that should help too.

The math trade will open up (software - wise) on June 17th. That is the day after Origins. I'll make a video of how to use the software once we are up and running. In the meanwhile, do the following:

1. Set aside the games you'd like to trade. Don't be afraid to include or also trade promos and extras.
2. Register at www.abecorn.com. That is the program we will be using this year.

We had about 180 individuals last year and we're hoping to control the chaos even for this year.

Thank you for getting a ticket to the event. GenCon has bean counters who determine who gets how much space based on the tickets. Our 180 individuals had 108 tickets. The tickets are free and we'll have a raffle this year to get more folks to get tickets.

Stay tuned for more info.
 

You will put your games on the site, then select which games or the amount of money you are willing to take for the games. It then runs an algorithm that will maximize the total number of trades possible without doing arbitrage(trading like for like items). By doing this it creates like chains of trades to get you possibly what you wanted. You will have some items that likely won't trade. It is a fairly simple process. You can read more here. https://boardgamegeek.com/thread/287152/math-trades-dummies

I am surprised though that Gencon allows Abecorn trades personally. Since there is so much cash that changes hands with it and it seems to go against this policy.

"No monetary transactions of any kind are allowed outside of your Exhibit Hall booth without prior approval by Gen Con. Violation of this rule may result in the cancellation of your event, removal from the convention, barring from future conventionsand may impact relations with other Gen Con departments as well.Some events and companies are given approval to make monetarytransactions.All approved sales locations must prominently display a valid Gen Con sales license.If you witness any transactions and are unsure if they have been given official approval, please inform the nearest Event HQimmediately.Permission for sales is only provided to key sponsors and specific event programs. General companies or gaming groups will not be granted permission, but you can email [email protected] confirm what is feasible if you have a specific idea you want to explore. Allapprovedsales at the conventionrequire a valid business license for the city and state.The EO is responsible for all costs incurred for setting up sales, as well as securing any necessary licenses or permits"

Not sure how each trader would get sales approval to trade cash but maybe they gave permission to Abecorn for the cash trades since they also sell games? With OWLGS you used to have to post gift cards instead to get around the Cash policy. Last year 21% of all trades were for cash.

This is the results of last years trade if you want to look at it. https://trade.abecorn.com/#/trade/5b1880383ef9a3003c562d24

Anyways that is how it works and what you can expect.

I’m looking forward to trading my Monopoly for Candyland. :D

The Math Trade is now open for posting trade materials. There are RPG materials (mostly Pathfinder books) posted as well as board games.

https://trade.abecorn.com/#/trade/5d0b37095908010043109cab

For people new to a math trade, I've made a quick start guide. Ask if you have any questions:

https://www.dropbox.com/s/xger8itqqe6x4yq/Abecorn%20QuickStart%20Guide.pdf?dl=0