Maximum Number of Shuffles

This is one of several user guides on specific topics. The directory for all user guides is here.

When you generate a random deal, or generate a deal from a shaper, the deal generator uses brute force to find a suitable deal. The random deal is the easiest of all because it shuffles the deck one time and that’s your random deal. When you generate from a shaper, the program starts with a random shuffle, then it examines the resulting deal to see if it conforms to your shaper. If it does, then there’s your deal. If it does not conform, then the program shuffles the deck and examines the next deal, and the next, and so on until it finds one that suits your shaper or else until it has shuffled the deck more than the number of times you selected in Maximum Number of Shuffles.

You can set that maximum number of shuffles to one of a list of values ranging from 10,000 to one hundred million. The default is one million, as shown above.

This setting is left over from the early days of this program, when the web page performed no editing of deal configurations. Then, it was quite easy to request an impossible deal—one with more or less than 40 HCP in the deck, or impossible card distributions. Without Maximum Shuffles, the generator would run forever because it would never find a conforming deal. Imposing a shuffle limit was a quick and dirty way to prevent long-running generator sessions. This was especially important when the generator was a centrally-located server program that could only support one user at a time.

The current version solved both problems. The generator now runs in your browser, so you have it all to yourself and it harms no one else if it runs a long time. But impossible deal requests are much less likely now, thanks to the way the shaper and the recipe maker panels work.

Max Shuffles does still have its uses, though. If you try to generate a deal and you get an error dialog saying that you exceeded the maximum shuffles, that probably means that you have used the shaper to request not an impossible configuration, but one that does not occur often in nature. Say you specify 39 HCP in North, or a two-suited hand with zero HCP, or any number of unusual deals.

If you get such a warning, you can do one of several things: 1) change your shaper to something more likely; 2) use a fairly detailed recipe instead of the shaper; or 3) select a higher value for Max Shuffles and try to generate it again; or 4) give up—maybe you requested that odd configuration by accident.

One more thing about long-running generators: if you set “Number of Deals” to something other than 1, after hitting Max Shuffles on the first attempt the program will start over from zero shuffles on the next attempt and will probably hit the Max again, and so on until it has tried it for all of your Number of Deals. So if you make a shaper with 37 HCP in one hand, and you request 128 deals and you have Max Shuffles set to its highest value, be prepared to watch it run for a long time.