[WIP] Shuffle big deck of cards

This tool helps you divide a big deck of cards into smaller piles to facilitate shuffling.

Explanation for how and why to use this tool are after it. This is a work in progress.

Number of cards (approximate, aim higher rather than lower):

Time per displayed card (in milliseconds):

How to use

This will divide a deck of card into 2 piles (sub-decks) randomly. If you need even smaller sub-decks, do this again to each sub-decks.

When you press start, arrows and numbers will appear, from the right, ex: 2← and 3→. This tells you to put that many cards from the deck into the left or right pile. Note:

• The arrows always alternate, so they are mostly a reminder.
• When an number is higher than 1, you can either place the cards in any either. So a chunk of 3 cards vs 3 times 1 card and anything in between are just as good. The goal is to do it quickly enough to follow the rhythm.
• If you miss a number or put it in the wrong pile, it's no big deal. The goal is just to have a better randomness than if a person does it in his head. So just keep going.

Now that you have smaller decks, you can shuffle them individually as you normally would.

When done with shuffling each decks, just stack them on top of each other without trying to shuffle them together. Done!

Why

Some board games have a massive amount of playing cards. Terraforming Mars has about 450 when you have all extensions, and while you play, there is a tendency to sort cards that fit together. Properly sorting the cards is important to ensure some regularity in the way cards are dealt / drawn.

But properly shuffling that huge amount of cards can be difficult. Doing a riffle shuffle on such a big deck is quite a challenge. Dividing it manually and then trying to merge the sub-decks manually is also not ideal. So this tool provides a way to make it more intuitive and straightforward. Here is a basic explanation of the steps:

1) Use this tool to randomly divide the big deck into smaller decks.
2) Shuffle the smaller decks as you usually would. (ex: do multiple riffle shuffles)
3) Stack the decks on top of each other. No need for further shuffling.

The reason this work is that the division in smaller decks using this tool use actual randomness. So in which bucket a card ends up is random and any other card in that same deck was picked randomly. This means that there is no need to do extra shuffling to when mixing the decks. You can stack them on top of each other. Now all that matters is to do a good job shuffling the smaller decks now.

Something nice about this way of doing it is that players can each be shuffling one of the smaller deck and when each is done, the shuffling is done.

For shuffling the smaller decks, if you are not doing riffle shuffles, mash shuffles, or other kinds of shuffle where cards get very interlaced, you are likely not properly shuffling those decks. How many should you use? Depends on how many cards in a deck and how well you want it to be shuffled.

The question is what is sufficiently random/shuffled. This is subjective. A common suggestion online is 7 riffles for a 52 card deck. If you have more cards in a sub-deck, that number should be higher. I won't go deeper in that rabbit hole, at least for now... But it is really interesting.