Luck is pervasive in Weiss Schwarz. From what you are able to pull off to how much damage you take is entirely determined by it. Randomization of the deck, shuffling, is what ensures that Weiss games are fresh and fair. Thus, shuffling properly is a key to ensuring that Weiss is fun for everyone. However, it’s not immediately obvious what shuffle methods actually adequately randomize a deck. Some commonly used shuffle methods take forever and even de-randomize a deck! Appropriate shuffling methods on the other hand can randomize a deck with only a few quick iteration. Thus, we’ll look at several shuffling methods that are inappropriate and some that are.

What shuffling methods are inappropriate?

Pile Shuffling

Pile “shuffling” consists of dealing your deck sequentially into several smaller piles, then re-assembling them. This does not randomize the deck at all. You do not break the existing order of cards with this method with the exception of the few cards at the arbitrary boundary. You would be able to know where each card is exactly if you knew where it was to begin with. Given that Weiss takes an open zone and remakes the deck with it, pile shuffling presents an obvious problem. It is very easy to stack a deck during the game. Heart of the Cards suggests in their Weiss Grand Prix rules that if you see your opponent re-arranging their climaxes in their waiting room, it is likely a precursor to this sort of cheating and you should call a judge.

On top of the fact that it can be easily used to cheat, it easily takes up to half a minute to perform. Given that matches are 20 to 30 minutes in length, this is too much time for in game randomization. Since pile shuffling does no randomizing and can be used to cheat, it can be reasonably considered slow play. For this reason, Magic the Gathering has put very strict limits on how many pile counts you may perform, one for the sole purpose of counting the number of cards in deck, and they cannot be the only shuffle you perform.

Magic is right. There is no reason to pile shuffle. Do not do it.

“Hindu Shuffling,” packet shuffling, and overhand shuffling methods

These methods grasp a packet of cards and move them to the top or the bottom of the deck. Like the pile shuffle, this does not randomize the deck, and if you know the order of the deck beforehand, you can stack the deck. The Hindu shuffle is a favourite of magicians for this reason. Overhand is also the preferred shuffle method of Yugi Moto, which explains why the “Heart of the Cards” never fails.

If you catch your opponent Hindu shuffling, you can’t call them for slow play given that it is fairly quick, but you can give their decks a few mashes to introduce more randomness. If they continue to only use this method of shuffling, you can ask a judge to observe their next shuffle to see if it is inadequate.

Appropriate Shuffling Methods

The appropriate methods of shuffling have several things in common. First, they break up the order of cards by interweaving them in an uncontrolled way. Second, they can be easily performed repeatedly. Finally, they can randomize a deck of any size, randomize here means that any deck order is as likely as any other with several applications of the technique. The two most used techniques are the riffle shuffle and the Faro/Mash shuffle.

The riffle shuffle is the most effective method of the two. It can randomize a Weiss deck in as few as 9 iterations. It is also very quick, as you split the deck roughly in half, then run the cards past your thumb to interweave them somewhat randomly. The main drawback of riffle shuffling is that it can damage cards by bending them. To reduce bending, the “bridge” part of the technique is optional, as it isn’t the part that is interweaving cards.

If you are worried about damaging the cards, the mash shuffle is a reasonable alternative, and the method of shuffling used by Weiss judges. Simply split the deck, align the two halves at the corner, and let the cards fall into each other. As far as randomizing goes, this method tends to be a bit clumsier than riffle shuffling as it’s easier to drop cards. However, it’ll still quickly randomize a Weiss deck.

A note on Perfect Mashes and Riffles

It is possible to riffle shuffle or mash shuffle in such a way that you end up with the same order deck that you had before shuffling. This occurs if you split the deck exactly in half, then ensure that the cards are perfectly interlaced. This makes the usually random process of cards falling into each other deterministic. Thus, you are controlling how the cards fall. If you perform perfect shuffles a specific number of times, 21 perfect riffles for a Weiss deck[1], the pre-shuffle order of the deck will be preserved. It’s unlikely that anyone will perform exactly 21 shuffles during a game situation. To ensure that you are avoiding the possibility of a perfect shuffle entirely, make sure there is an unequal number of cards in each hand.

Conclusion

It is easy and fast to randomize your deck. You are given time at the start of each match to randomize your deck. If you take a minute, and use appropriate methods, you’ll have no problems. Inappropriate shuffle methods waste time and can be used to facilitate unfair play. You have the ability to mitigate their use by an opponent, and should do so whenever possible. With this in mind, you can maximize the best part of Weiss, the unpredictability.

[1] Number generated by applying the algorithm in R.