Thursday, 8 November 2007

card shuffling

How do you shuffle your cards? In my game collection, I have card games (Mystery Rummy series, Bohnanza, Lost Cities), cards games with some other components (San Juan, Settlers of Catan Card Game, Jambo), and boardgames with cards (Ticket To Ride, St Petersburg, Hacienda, Lord of the Rings). When I think about it, cards are a very clever mechanism that fulfill many purposes. They introduce luck and randomness and variability in games. They store information and define the boundaries of a game (or an aspect of it) and probabilities of those events / resources / buildings / powers appearing in a game. They are a convenient way to hide information from your opponents. Some card decks control the flow of a game, e.g. the cards in Domaine, which are divided into four subdecks from A to D. The D deck is placed at the bottom and A on top, and each subdeck has different characteristics for the start, middle and end of the game. Twilight Struggle uses a similar concept. With cards, come the need to shuffle them (usually).

The objective of shuffling cards is to make their order random. Once my cousin Edward brought up an interesting question about shuffling cards. Does a good shuffle mean when you deal out the cards, everybody will get bad hands? During a card game, if someone gets an unusually good hand, the first reaction will often be that the shuffling wasn't done well. Following this logic, it seems good shuffling means you get lousy cards. This is not correct. The objective of shuffling should be to make things random. Being random does not mean always getting bad hands, but it does mean that you should be less likely to get good hands. In card games where you deal out all cards, like Bridge, or Big 2 (Cantonese: "Cho Dai Dee"), sometimes getting a good hand means your opponent is also getting a good hand, e.g. you are getting many cards of one suit, then it is more likely that your opponents are getting more of another suit. Anyway, the objective (as far as I can think of), should always be to make the deck random.

When playing with standard playing cards, I do the interleave method. I don't know the right term for this so I'm inventing this term. You split the deck into two equal halves, and hold each half with one hand. You hold the two shorter edges of a face-down half deck with your thumb and middle finger, and press your index finger on the back of the half deck. Placing the two half decks near each other, with your middle fingers touching the table, and your thumbs near each other, you release the cards by gradually releasing your thumb. The cards from the two half decks will slap onto the table, taking turns between left and right deck, and overlapping each other. Once all cards are released, you get two half decks partly overlapping. You join them into one full deck. Gosh, that was quite a challenge to describe in words. Anyway, this is the interleave method. I have heard that doing this seven times gives the best results. I wonder whether there is any scientific proof for this. When I play the games in my collection, I do not use the interleave method.

One of the methods that I use is the overhand method. I'm not sure of this term. I think this is correct. This is the most basic method for shuffling cards. You hold the deck of cards with your left hand with your palm facing up and the deck being held on the long sides by your thumb and fingers. You use your right hand to draw part of the deck from the middle or bottom of the deck, and then put this partial deck back onto the top of the deck. You repeat this several times. Obviously this is a much less efficient method compared to the interleave method, but the important thing is it doesn't bend my precious cards.

Another method which I like is the disperse method (again, my own terminology). You just deal out the whole deck of cards into four piles. You can deal systematically from left to right, or left to right to left (etc), or deal randomly. You can use more than four piles. Once all cards are dealt out, just stack those piles together to form a new deck. This is good for dispersing cards of the same suit / same colour. In many games when cards are played or discarded, similar cards tend to clump together. Using this disperse method will break them up. This is suitable for games like Ticket To Ride, Lost Cities. After doing the disperse shuffling, I usually do a few more overhand shuffling to mix things up a bit more.

I also often use a 2-dealers version of disperse shuffling. This is when Michelle and I play 2 player card games, like games in the Mystery Rummy series. We divide the deck into two, and then both of us do disperse shuffling onto the same four piles laid out between us. This is even better shuffling than 1 person doing disperse shuffling. We do make sure that the cards are aligned in the same direction, i.e. I'll be holding the cards in the normal way, which Michelle holds the cards upside down, so that when we both deal into the four piles, the cards become aligned (because she is sitting opposite me).

On thing that I am very particular about is that cards must be the right side up, at least for the types of cards where the direction you hold them in matters, e.g. Hacienda, the Mystery Rummy games, Ticket To Ride ticket cards, Lost Cities, Lord of the Rings feature cards (those picked up on specific spaces on the main board or scenario boards), Ark, Blue Moon City, San Juan, Settlers of Catan opportunity cards. When the cards are discarded during the game, I must have them all discarded in the same direction. I cannot resist rearranging the discard deck if other players discard in the "wrong" direction. I don't do this for all games. Cards that do not matter are like those Ticket To Ride train cards, Lord of the Rings hobbit cards, China cards, Settlers of Catan resource cards.

Other than shuffling, I also apply some techniques for discarding cards. For some games, I discard cards to more than one discard deck, to make it easier for me when I pack them up or to make it easier to shuffle for the next game. For example, when playing Ticket To Ride (and others in this series), I will create four or five discard decks. So, for example, if I play 4 red cards to claim a 4-length route, I will discard each of the four cards into a separate discard deck. This breaks up the cards of the same colour. Same principle as disperse shuffling. So, after one game of Ticket To Ride, I usually just do some overhand shuffling and don't bother to do disperse shuffling. Saves me some work. When I play Lord of the Rings, I also create two discard decks, one for hobbit cards and one for feature cards. Makes life much easier when I finish the game and want to pack up. When packing up I sort the feature cards according to the locations, and then stack them up in the correct order. So, the next time I play, I can set up the game very quickly. For San Juan, when I put away the game after playing, I will put two indigo plants on top, because I usually play this only with Michelle, and at the start of the game everyone gets one indigo plant.

See the bottom of this photo of Lord of the Rings (with the Battlefields expansion). I have two separate discard decks for hobbit cards (right) and feature cards (left)

Ticket To Ride. The upper row are the five open cards that players can choose from, and the lower row are four discard decks.

Coming back to shuffling, different games have different needs in terms of shuffling cards. In some games there is a natural tendency that cards will get arranged into same suits / colours, or in an ascending number order, etc. In these games there is a need for good shuffling to make things random, because during a game the cards will tend to get arranged in some order. Examples of games with high shuffling needs are Ticket To Ride (especially when people like to claim those long routes - you'll see lots of cards of the same colours, maybe with some jokers too, all grouped together in the discard deck), Lost Cities, Bohnanza. Actually there really are quite many in this category. In some games, there is not as high a need for shuffling, because there is little or no relationship between one card and another, and they don't tend to get grouped together. E.g. San Juan. There is not really any concept of suit or colour. There is still some level of clumping, e.g. if a person pulls off a guild hall strategy, he/she will probably have the guide hall plus lots of cheap production buildings grouped together. But in general, I don't bother shuffling San Juan cards too much. Jambo is another example. On The Underground too. In some games, don't even bother shuffling. If you shuffle the Settlers of Catan resource cards, someone will call you an idiot. These resource cards are mainly an accounting mechanism. They are sorted by type and laid out as separate face-up decks. You collect an appropriate card when your settlement produces a resource. Similarly, the money cards in Hacienda, which is basically just like paper money in Monopoly or Power Grid. In Lord of the Rings: The Confrontation, you need not bother shuffling your cards either. You always start with 9 cards, and your opponent knows what they are. He/she just doesn't know which one you'll secretly pick to play when it is time for your characters to fight. So, don't bother shuffling unless your opponent is the type that secretly remembers the order of your cards and tries to tell what card you have chosen by looking at the position in your hand from which you picked the card. I hope I don't have to game with such characters though.

Card shuffling methods can also be applied to other types of boardgame components, e.g. Carcassonne tiles, and event tiles in Lord of the Rings. I use the disperse shuffling method for Carcassonne, and I usually have 5 or 6 stacks of tiles (as opposed to 4 discard piles of cards). I am a big fan of the disperse shuffling method.

Can anyone tell me what are the correct terms for all these card shuffling methods?


Anonymous said...

I'm pretty sure that overhand shuffle is the right term.

Your "interleaf" shuffle is normally referred to as a riffle shuffle in my experience.

Hiew Chok Sien said...

Thank you! I remember I have read about the different names of the different shuffling methods before, but I can't remember them.

wankongyew said...

Heh, if you think shuffling cards is a big issue for boardgames, you should have seen how serious an issue it is in Magic: The Gathering, where tournaments mean serious money. Technically, the "interleaf" shuffle is the best at randomizing as you say, but it would be impossible to do that with MTG. Not only are the cards super expensive, they're frequented protected in sleeves so thick that they look more like plastic chips than cards.

In case you're unfamiliar with Magic, cards are either spells or lands. Spells do stuff but only lands yield resources to pay for stuff. Each turn, you can only put one land into play. This means that if you have a hand full of spells but no lands, you're screwed. Alternatively, having a hand full of lands but no spells is bad too because you'll have plenty of mana but no spells to actually spend them on.

So Magic players will actually stack their decks prior to a big game. The optimal ratio is about 22 land cards in a 60 card deck, so they'll arrange their decks with one land card, two spell cards, one land card etc and hope that the order doesn't get messed up too much after shuffling.