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Aussie Maths Trade RSS Feed

This is the documentation wiki for the Australian Maths Trade. The current trade is CANCON 2020 Swap / Buy (not Math Trade) List

How do I know it's on?

The Australia-wide Maths trades happen typically twice a year before large conventions that help people organise no-postage mules to move games around. There are also occasional whole-city maths trades which are organised to be postage free. If you want to hear about them, you should subscribe to both of:

Australian Ultimate Trade Subscription thread and Maths trade notification thread.
The Australian Trade and Sale Meta-List


What is it?

A Maths Trade is a trading method that allows participants to trade games with a large pool of games made available by many other users, rather than a one-for-one trade with a single other person.

It utilises a program running an algorithm to determine which items submitted can be traded for items which have been requested by its participants. The program allows you to offer to trade games (or other items, as allowed by the rules) and create a list of one or more items you would like to receive in return for your item. Thus, you may trade away things you don’t want in anticipation of receiving things from a list of items that you consider more desirable. The clever part of the algorithm is that the person you send your game to may not be the person you receive one from.

In essence, it matches items you (and all the others) submit against items you (and all the others) want to determine what can be traded to whom to ensure as many items as possible get something they asked for.

For example:
• Aragorn has Elfenroads, and would like to trade it. Aragorn wants the game Bang
• Bilbo has Bang, and is happy to trade it, but does not want any of Aragorn’s games. Bilbo would like Carcassonne
• Celeborn has Carcassonne to trade, but doesn’t want any of Bilbo’s games. He wouldn’t mind getting Elfenroads.
So, there are no trades possible between any single pairing of those people.

However, the maths trade algorithm determines that a game is available that meets what each person wants, and works out the way to do this:
• Aragorn sends Elfenroads to Celeborn and gets Bang from Bilbo;
• Bilbo sends Bang to Aragorn and gets Carcassonne from Celeborn;
• Celeborn sends Carcassonne to Bilbo and gets Elfenroads from Aragorn.
Everyone sends away an item and receives an item they wanted in return.

This is a simple demonstration of the mechanic of a maths trade. With more participants, more games, and more possible selections from the items people want, the possible combinations grow exponentially, and some very convoluted trading loops can be obtained.

How does it work?

It is initiated with a Geeklist, usually created by the Trade Moderator. The Geeklist header will stipulate the rules that will apply to the maths trade, and the Moderator will ensure that everyone who submits to it complies with these. Rules may vary between different trades, so before submitting to the Geeklist you should read all the rules, make sure you understand and are willing to comply with them, and ask questions beforehand if necessary.

If you are prepared to honour the rules, you add an item to the Geeklist – use the Add Item link in the bottom right-hand corner of the Geeklist header. Enter or select the relevant item from the prompt, make sure you choose a picture that correctly matches the item you are submitting, and enter in any other details; usually, the Trade rules will require you to put in details of the condition of the item, the version, and anything else relevant to your offering.

You may also include anything else you wish within the item details. This may, for example, include expansions that are included with your offering, or other items altogether (commonly referred to as “sweeteners”, in that they make your item a more desirable option to others).

Bear in mind that you will not get your item traded unless someone else includes it on their Want List. Accordingly, you want to try as much as possible to make your item something people are likely to want, or include enough sweeteners to do so.
Similarly, simply adding an item to the list does not automatically compel you to trade it; you may submit a “blank” Want List that has nothing against it for that item (see below), in which case it cannot trade. (However, once all Wants Lists are submitted and the Moderator closes the trade, you are obligated to comply with the results. It’s too late to change your mind after the trade is run, so make sure you put together your Want List carefully!)

Note that you are not able to put conditions against your item (eg. you will only pay postage to certain areas, you will only include sweeteners if it trades to a cute blonde, etc.). As the item you submit is potentially available to any participant in the trade, you are honour-bound to abide by the trade results and send your offering complete and without qualification.

As long as the rules permit it, you can add as many items as you want, you can add items already listed, and you can add anything within scope of the allowable submissions as defined by the rules. The only caveat is that when the trade completes you must be able to get every item you have offered, as described, to whomever is allocated to receive them.

The Moderator will specify a closing date for submissions. Anything you want to add to the list needs to be done before that date/time. As soon as the list is closed, you can submit your Want List.

How do I get what I want?

To start with you prepare a Want List. Instructions for how to build a Want List are detailed below in the YOUR 'WANT LIST' section; in short, you create a text file with one line per item you've submitted and a list of things you’d be happy to receive in trade for it.

Towards the closing date of the maths trade, the Moderator will assign trade codes to every item on the Geeklist. The actual content of this trade code is irrelevant, but they will always be in a specific format (currently 7 digits + hyphen + 5 characters: #######-TEXTX). The trade codes themselves are important as they are used as the item references in your Want List.

For every item you have submitted, you make a list (using the trade codes) of the items you would be happy to receive in return. There may only be one, which is fine, but the more things you provide as acceptable trades for your offered items, the more opportunity that algorithm has to find trade matches for you, so the more likely it is you will get a successful trade.

In addition, the Australian Maths Trades use an added facility allowing cash transactions as well, whereby you can offer your item in return for a certain payment (as well as possible other items), and/or you can offer cash to try and obtain things you are interested in. Guidelines for how this works are detailed in the section Trading Cash below.

The rules will give a deadline for the submission of Want Lists. Some people will get theirs in quickly, others will leave it to the last minute. Those in the former group will usually take every opportunity to mock, castigate and vent their frustrations at those in the latter group. Regardless, when all users have submitted lists, the Maths Trade is ready to be executed.

The Australian Maths Trades use a program called TradeMaximizer which has been substantially modified by John Farrell (Friendless), a wonderfully friendly and helpful BGG user. A Want List is not difficult to compile, and by following the instructions and giving a little attention to detail, each user can contribute to the smooth and easy running of the Trade and get the best results from it.

The TradeMaximizer compiles all the Want List and then runs through them using it's logic - the core of which is based on the most desirable outcome being the solution that gives the most possible trades (ie. as many items as possible offered up for trade do actually find trade matches).
As noted above, very few of the resulting trades will be A-B, and some may have long loops of people sending items (or money) along the chain in order to receive something in return.

Generally the program runs quite quickly, and the results get posted in a list specifying which items have traded, so which users have items to send (and to whom), which items you receive for your trades, and any items you offered that failed to trade. Then, in accordance with the rules, you get your successfully traded items away to their receiver(s), and await your inbound goodies.

Stuff I need to know about

It's not really that complicated, and once you've done one you'll likely be addicted to them thereafter... a bit like when you got into boardgaming in the first place!
But there are some basic guidelines that will help you (and everyone else):

  • First, and perhaps most importantly: you can only receive items that you have asked for! The mechanism of the maths trade makes it impossible for you to receive an item outside of what you put into your Want List.
  • Despite how convoluted the program can be, at the end of day each and every item you offer may trade for one single other item only.
  • The more things you are prepared to accept in return for what you are offering, the more likely it is to have a successful trade. However, read the rules - you may be up for postage costs or other obligations, so make sure you consider this when compiling the list of games you'd be happy to receive in return.
  • If you decide there's nothing you want in return for your offering, you simply submit a blank Want List for that item. This will prevent it from trading (because the program will be unable to create a suitable trade match for it).
  • Your item can only trade if somebody else adds it to their Want List. If you put up crap nobody will be interested in having, it's unlikely to trade.
  • Some users will put up items that are likely to be sought after by many other users. There's no guarantee, but the best way to improve your chances at winning such an item is to put up something of commensurate desirability (or value) to as many other users as possible.
  • Further to the above, when certain items are particularly appealing to you, check that owner's wishlist; you might discover you can offer something you hadn't considered, and thus improve the likelihood of a great trade.
  • If you're adding items as sweeteners, try to ensure they have synchronicity somehow and thus are more likely to appeal to someone interested in the bundle.
Some items are destined not to trade. Some users will permit their submitted items to be traded privately (or sold) before the trade runs; considerate users will modify their listing to note that the item is no longer available for trade. Other items will not trade because the person offering them did not find anything suitable they wanted and submitted a blank trade list.
  • In most maths trades items will be added right up to the last minute... there's always some in every crowd! However, the consensus is that adding items earlier (particularly things that are likely to be desirable to a wide audience) have a greater possibility of pulling lurkers or "undecideds" in, and the more participants the better the results are likely to be. Remember that simply adding an item to the list does not force you to trade it.


This is scary, can I trust people on the internet?

No, don’t trust people on the internet as a matter of course. The super good thing about the Australian Maths Trades is that a lot of the people involved in it have already met each other at conventions (BorderCon, ConVic, ConCentric, CanCon, etc), and then they’ve met the less well-travelled people at their local meetings. So, we mostly know each other. We’re always looking to extend that circle of known and trusted fellow geeks.

I don’t have a clue about the Maths Trade, I just want a copy of Agricola

Getting a particular game is a little difficult, as it depends on someone else wanting to get rid of it. The best thing to do to start with it is to find the geeklist and subscribe to it, find the discussion thread (which will be linked to from the header of the geeklist) and subscribe to that too. When items you want come up on the geeklist, make a note. If it’s exactly what you want, see if you can figure out a trade straightaway (a “pre-trade trade”), as the owner of the game is not obliged to leave the item in the trade if they get a good offer. This is a contentious topic as “all the good stuff gets taken”, but it’s within the rules, and as all board gamers know, playing within the rules is the prime directive.

What about want-lists and all that?

After all the listing has been done, and a great deal of the arguing, comes the technical phase. This is where you have to write down what you want and what you will give for it. As long as you know what you want and what you’ll give for it this bit isn’t too hard, especially as there are some web interfaces to help you figure it out. Also, Friendless is the guy who has to deal with your mistakes in this phase and he has the patience of a saint - a cantankerous nerdy saint, to be sure, but he won’t let your mistakes break the trade. Also, *if he notices* you doing something which may not be what you want, he’ll help.

What if I get committed to a deal that’s no good?

The trade is designed to be no-risk, no surprises. In particular, you won’t have to give A to get B unless you’ve explicitly said “I would give A to get B”. There’s no mysterious screwage mechanism EXCEPT the post office. Postage can be expensive and it can be a risk, as our rule is that sender pays shipping. Note though that Aussie Post has an on-line service whereby you can send a game like Puerto Rico in an official Aussie Post box (costs $3.40 or so) to anywhere in Australia for $15.05. Sending games that don’t fit in that box can be difficult and expensive. If in doubt, leave them out of the trade. Having said that though, if you explicitly committed to a deal that turned out to be no good, the conventions of contracts apply and you should honour the deal.

It all went haywire and I got screwed!

That seems unlikely. But if it happens to be true, some of the benevolent and overstocked gamers around the country will likely come to your rescue. It’s in our interests for the trade to keep its good reputation. Nobody has been screwed yet, but some people have been miffed.


Several years ago the Trade Maximiser code for the Aussie maths trades diverged from the code for the rest of the world - this is essentially because Friendless and JeffyJeff were taking things in different irreconcilable directions. As a consequence, Aussie Maths Trades don't use the OLWLG, but they do have a nice HTML output format, geeklist integration (and consequently better error messages) and the option of trading for cash. Mr_Lunch and thepackrat have been working on some on-line tools (see below) for creating and checking wants-list submission, so that the Aussie suite of tools is very useful, just totally different to what the rest of the world does. If you're interested in the Trade Maximiser code used in Australia, just PM Friendless.


General Guidelines

A 'Want List' is a text-only submission to the Maths Trade operator detailing all of the items/payments you wish to offer, and/or what you're looking for in return. You propose one of your items for one item (or one of a list of items) you would like in return; this includes cash offers and/or requests (covered below).

It is required after submissions to the trade Geeklist are closed, and there will be a posted deadline by which you have to have them in by.

The fundamental things to be aware of are that:
1) You can only ever receive something you ask for in one of the lines of your Want List; and
2) You will only get something if you manage to trade out your item, so the more items you have for each line on your Want List the more likely it is to get a successful trade for you; and
3) The trade works on one-item for one-item, but it does not mean necessarily that the item you trade will go directly to the person you receive from. This is particularly relevant in cash trades, ie. the person you pay may not be the person sending you a game.

Accordingly, you need to make sure that every item on your want list is a satisfactory trade for you... remembering that in all Australian Maths Trades the SENDER pays for shipping, so if you're not going to be content to receive a well-used Munchkin in return for your virgin copy of Queen's Gambit (including possibly paying postage to Christmas Island for it as well), then don't put it in.

The Program

The program, TradeMaximizer, works on the principle of getting the most number of trades possible, with the moderator usually advising the specifics of the ALGORITHM to be used. In the Australian Maths Trades these are the options that are set:
SCALED-PRIORITIES means that each of items on each line is considered in order, with items appearing earlier being given higher priority for trade success than subsequent items. Thus, when creating each line for your submission, order the items you want in the order you most want them. However, the order of the rows in your list does not matter, and will not affect the trade probabilities.
ALLOW-DUMMIES provides the facility to use an alias (covered below) where multiple copies of something are available and you'd be happy to receive one, but not more than one.
REQUIRE-COLONS and REQUIRE-USERNAMES are formatting requirements that help reduce the possibility of errors when the engine runs.

A Want List is a straight text file. It should not have formatting of any sort, but it should be structured correctly - this makes the Admin's life significantly easier. Each line (row) of your list should be structured in the same way.

Starting the List

Note that this presumes you are preparing your Want List manually. There are tools available to assist you preparing this with greater autonomy, and these will be detailed elsewhere on this page.

Every item on the trade list has a designated trade code added to it in the format #######-TEXTS, and you will need these for each item you want to put in your list.

Firstly, make a list of the games you are interested in receiving, ensuring that you correctly note the trade code for each item.

Then make a list of any items you have added, beginning each line with your username in brackets followed by a space, followed by the trade code for the item you have put up for trade and a colon:

(myusername) 2132131-GAMEA:
(myusername) 2132132-GAMEB:
(myusername) 2132133-GAMEC:
(myusername) 2132134-GAMED:
(myusername) 2132135-GAMEE:
(myusername) 2132136-GAMEF:

Note the trade codes used herein are examples only, and do not represent real items from any trade list.

Duplicate Protection (Aliases)

Whilst building the list of items you want you will come across games that are listed multiple times. In the likely circumstance that you are not one of those people who wants, for example, three copies of 'Race for the Galaxy' (yes, there are people like that!!), you can create a dummy (an alias). This allows you to add the game in more than one line of your Want List, but the trade engine will only find one success for it, so you can only receive one copy.

The same functionality can also be used to build a selection of games where they are not the all same and you would be happy to receive any one (and only one) of them. You can use it to select just one of any group of items you desire. For example, if you wanted a 2-player game, but only one 2-player.

To create an alias, create a name for it; this can be anything you like, but it must be unique in your list and it must be preceded a % sign. And, as with any other row on your list, the start of each line must be your username surrounded by brackets and it must have a colon after the submitted item trade code.

Do this for each game you want where you want only one from the selection.

(myusername) %2PGAMES:
(myusername) %RFTGS:
(myusername) %WGAME:

Then, next to each alias, put the trade code for the items you want. As with a normal want list, these should be in order of preference (for example, you might want to put a version listed as "new" ahead of one listed as "good", but you'd be happy to get either).

(myusername) %2PGAMES: 1231231-JAMBO 1232341-JAMBO 1233451-ROMII 1234561-ROMII
(myusername) %RFTGS: 1241242-RFTGY 1251252-RFTGY 1241262-RFTGY
(myusername) %WGAME: 1251253-STRUG 1251263-DOOOM 1251273-ASLSK 1251283-PATON

Thus, in this example...
%2PGAMES would allow me one 2P game from the two copies of Jambo or two copies of RomaII available;
%RFTGS would allow me one Race for the Galaxy of the three copies available;
%WGAME would allow me one wargame of the four I am interested in.

Then, you will use the alias identifier code you have created in one or more lines of your Want List. It doesn't matter how many times you use it, you can only receive one item (total) from all the lines of each dummy group.

Important Note! If you list any of the individual games in a wantlist, rather than always using the %GROUP, you can still end up with duplicates.

Trading Games for Games

Now, to each row of the list of games you submitted, add trade codes for any of the games you would be happy to receive in trade, leaving a space between each one. You may have items in more than one line (ie. you would trade any of several of your items for a particular item). Where you are adding a game used in your alias list, use the alias code you created rather than any individual item trade code.

As noted above, you may be required to pay postage to anywhere in the country, so bear that in mind at all times when deciding what you'd be happy to receive in return.

Trades work one-for-one, so one offer on each line gets matched against one possible item. Thus, 2011111-CAYLS appearing on two (or more) rows can obviously only trade once, for one of the submitted items. (Incidentally, this means that if it trades once and there are no other options for your other items, your other items won't trade... the more items you are prepared to trade for each of yours, the more likely you are to get them all traded!)

Also, alias items only trade once; so, 2132132-GAMEB might trade for 2011111-CAYLS or 2012222-TBAGO or 2013333-FLIPR or a copy of Race for the Galaxy (in which case nothing else would trade for anything from the %RFTGS list) or for an item from the %WGAME list (in which case nothing else would trade from the %WGAME list, and nor would 2132134-GAMED trade).

Incidentally, remember that the TradeMaximizer will weigh trades earlier in the row as more desirable than those later, so prioritise. However, it will work to get get the maximum possible trades, even if that means you get your last choice for every item. Plan carefully...

(myusername) 2132131-GAMEA: 2011111-CAYLS 2012222-TBAGO 2013333-BTROL
(myusername) 2132132-GAMEB: 2011111-CAYLS 2012222-TBAGO 2013333-FLIPR %RFTGS %WGAME
(myusername) 2132133-GAMEC: %WGAME 2111111-DIPLO 2112222-CARCS
(myusername) 2132134-GAMED: %WGAME
(myusername) 2132135-GAMEE: %RFTGS %2PGAMES
(myusername) 2132136-GAMEF: %2PGAMES

Thus, in this example...
My 2132131-GAMEA might trade for any one of Caylus, Tobago, or Bridge Toll;
My 2132132-GAMEB might trade for any one of Caylus, Tobago, Bridge Toll, Aquaretto, or any one copy of Race for the Galaxt, or any one of my wargame selections;
My 2132134-GAMED might trade for any one of my wargame selections (but will not trade at all if one of my others items successfully trades for an item out of this group).

Trading Cash

You are also able to use CASH as an option in the Australian Maths trades, allowing contributors to both offer cash in trade for an item, and/or accept cash as a suitable trade.

Note that BGG now requires those receiving cash to go through the BGG Marketplace and pay BGG a 3% commission, see Cash Value Trades in Math Trades (and how to make a geek market listing for them). On page 6 of this thread it links to the section in the Geeklist Auction Wiki dealing with Listing Marketplace items (individual or bulk lot) -

If you are happy to accept cash for one of your submissions, simply add the amount to the relevant row of your want list.
(myusername) 2132131-GAMEA: 2011111-CAYLS 2012222-TBAGO 2013333-BTROL $40

If you want to offer cash for one or more items, add it as a row as you would a game, remembering correct syntax for the row: your username in brackets, offer, colon, items.
(myusername) $40: 2011111-CAYLS 2012222-TBAGO

Bear in mind that there is not necessarily a correlation between the amount you offer and the amount requested for any particular item. Because the methodology of a maths trade is not A <--> B, but may be A --> B --> C --> A (or even more complex), you could conceivably offer more or less for an item than the person requests and still end up with a successful trade. You can also make cash offers for items not submitted with a value and get a successful trade.

However, the simple rule to remember is that trades can only be matched against the items on each row of your list... if you offer something (cash or game) you can only receive respective items you specify (be they cash or game). You cannot possibly end up with a trade you have not requested.

You can also use a CASH offer to try for one item from a selection of several using the alias functionality, exactly as with any other trade.
(myusername) %GOODS: 1251253-STRUG 1251263-DOOOM 1251273-ASLSK
(myusername) $25: %GOODS

Important Note! The program allows you to specify an overall spending limit, so that the sum of any possible trades will not exceed that limit. You should do this if making cash offers as, by default, the program will otherwise use the highest amount you've bid for any single item as your total spending limit. Use LIMIT as the code and the same syntax...
(myusername) LIMIT: $60

The cash functionality works as follows:
The trade algorithm is run, and the program inspects the results. If anyone has exceeded their spending limit, their highest-priced successful bid is removed and the algorithm is re-run, continuing until all spending limits are satisfied.

Getting it finished

When you're done, put it all together and check your syntax: every line needs to
  • start with your username (in brackets), and
  • have a row identifier (alias name, item trade code, offer or limit), followed by
  • a colon, and then
  • a list of acceptable trade items (trade code, alias and/or amount), and
  • a LIMIT key word if you have included any cash offers.

When you're done, copy it into a Geekmail and sent to the Trade List operator as specified in the Geek List header.

Note: do not try to screw the system. The program will reject nonsense like this:
(myusername) $10: $20
(myusername) %CASH: $20
(myusername) $10: %CASH
(myusername) $20: $10
and, furthermore, the Admin will reserve the right to change the program to reject anything else he sees as a scam and not an honest trade.

TOOLS to help you

Ben (mr_lunch)
  • Trade Tools A nice overview of all the items, correlated with thumbs and wanted items that you can use to figure out what you want.
Bruce (thepackrat)


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