Support:

You can contact eXtreme Gammon by email at support@extremegammon.com. All correspondence, including technical support should be in English or French.

Make sure to check the Help in eXtreme Gammon by pressing F1 from any dialog to get specific help on its features.

About Us:

eXtreme Gammon is a product of GameSite 2000 ltd. We specialize in Backgammon programs. We invite you to check out our online Backgammon site for a FREE 30 day trial membership: go to www.gammonsite.com.

GameSite 2000 ltd is operated by Xavier and Michelle Dufaure de Citres and is dedicated to offering the best possible programming to the Backgammon community.

Frequently Asked Questions:

Registration:

Q: Can I use eXtreme Gammon on multiple computers?
A: Each activation is tied to one computer. however, you can get multiple activations for a discounted price of $25.00 after the first one.

Q: What if I change computer, can I transfer the registration to my new computer?
A: Yes you can. When starting eXtreme Gammon, in the registration window, open the activation manager. Enter your activation key and pick "Get Status" . Then you can deactivate your old computer and activate the new one.

Q: I just purchased the software using PayPal, why didn't I receive the registration key yet?
A: You may not have pressed the button "Click here to retrieve your activation key" after completing the payment in PayPal. Please contact registration@extremegammon.com to receive your key.

Analyze engine:

Q: In eXtreme Gammon rollouts, are checker play based on score and cube position?
A: Yes it is. All rollouts are made fully cubeful (by default). However it is to be noted that when rolling out a double position, checker play in both lines (resulting of "No Double" and "Double/Take") is made using the "No Double" line. You can pick the Rollout Option "For Take" to make decision in both lines using the "Double/Take" cube position.

Q: What is XG Roller?
A: XG Roller is a very level strong level of play, it does a short truncated rollout. It uses a 6-ply truncated rollout of 3600 games, using 2-ply for the 2 first cube decision and 1-ply for all the other decisions.

Q: What is XG Roller+?
A: XG Roller+ is the strongest level of play you can use in eXtreme Gammon, it does a short truncated rollout. It uses a 7-ply truncated rollout of 360 games using variance reduction, it uses 2-ply for all the cube decisions and for the 2 first checker plays. It uses 1-ply for all the other checker plays. The position at truncation point is evaluated in 2-ply.
Latest tests show it to be even stronger than a 5-ply evaluation: (see here)

Q: What is 3-ply Red?
A: The 3-ply Red level is using a sample of 7 rolls (out of the 21 possible) to analyze the position (only at the first Ply, subsequent ply use the full 21 dice). It is about twice faster than a full 3-ply while being only 10 Elo point weaker. This make this level a very good candidate for Deep Rollouts.

Q: What rollout settings should I use?
A: It depends of how much time you want to spent analyzing and the degree of confidence you want. 1-ply is very fast but may make some double (and a checker play) error. 3-ply level are about 400 time slower but have a very low error level.
We suggest you use variance reduction as it help get a significant result with lesser games rolled.
The confidence of the rollout (which can be view on the tooltip by hovering the mouse over the move) is the key number to know if your rollout was long enough. A good rule of thumb when comparing move is that the confidence value should be smaller than difference of equity between the moves.

Q: Can I see the Snowie Rating?
A: No. Our take on the Snowie Rating is that it is inherently flawed.
Snowie rating is the amount of equity (normalized) lost multiply by 1000 divided by the number for roll (for both players). The main problem of it is that it does not take into account forced moves or moves that are completely unimportant. For instance in Snowie, if you play a game and reach a position where are 100% sure to lose and play the next 10 moves rather than resigning your rating will be higher! That surely does not make sense.
Another case where the result is not proper is if your opponent makes a big mistake at the beginning of the game, get hit and dance for pretty much the rest of the game. His Snowie Rating will be very low because of all the moves you made and was sitting on the bar obviously making no error. But, after all, he was given one chance to show your skills but made a bad choice. In my book, he played bad every move and should be rated very poorly on that game.

We are committed to make eXtreme the standard in Backgammon and bringing back old system that we don't believe in is not something we want to do.

Since Version 1.10 eXtreme Gammon has the ability to display the Performance Rating. It is the equity per decision multiplied by 500. So the number are in the range of Snowie ER, but still take into account that force move are not to be counted.

Miscellaneous:

Q: Does eXtreme Gammon works on a Mac?
A: No, however some people successfully ran it on a Mac using a an emulator (Parallel Desktop). Note that 3D may to work in that case (Parallel Desktop 4.0 will support the 3D mode) . Also, Emulator are not supported officially, so in case of trouble we may not be able to help you.

Q: In the options/Analyze tab I cannot change the setting for some analyze mode, why?
A: The first 5 mode are built-in mode and cannot be changed. You can use the 4 last settings if you want to customize your own mode.

Q: In the options/Rollout tab I cannot change the setting for some Rollout mode, why?
A: The first 4 mode are built-in mode and cannot be changed. You can use the 6 last settings if you want to customize your own rollout.

Q: The mode I pick in the Options/Analyze tab is not kept, why is that?
A: The analyze tab allows you to define the mode. To set which mode is use go to the "Game" tab. There you can set the mode used for each type of player (with profile, without profile, computer and imported players)