I have a problem with card shuffling.
More specifically, I have a problem with shuffling a lot of cards. I own the card game Exploding Kittens, along with all three expansion packs, and I have sleeved every card (as the damage to the most-used cards acts as inadvertent card-marking). There are 167 cards in a full deck, and with the sleeves I'm using that results in a stack of cards 112mm tall.
This is an unwieldy amount of cards for anyone, and this game requires regular shuffling of the deck, as well as an initial shuffle. As this is a card-drawing game, this results in a large delay to game play. I would like to know if there is a method of combining the most common simple shuffling techniques (overhand and riffle/Faro) with splitting the deck and swapping piles with the people next to you that is optimised for both speed and randomness.
NB: I mentioned Faro shuffling above as the card sleeves I'm using make Faro shuffling extremely easy.
The problem is thus: in an average game of Exploding Kittens, players are required to shuffle anywhere between 1 and 140-167 cards (167 is the initial shuffle, 140 is the upper limit for in-game shuffling). Below 50 cards the deck is manageable by one person. For decks of 51 to 167 cards, up to 3 people are required to shuffle the deck quickly. What is the the combination of overhand shuffling, riffle/Faro shuffling and splitting the deck and sharing it with your neighbour that results in the optimal combination of speed (10-20s) and randomisation?
References:
https://en.wikipedia.org/wiki/Shuffling https://www.reddit.com/r/ExplodingKittens/comments/9pq6ui/big_obsessive_card_list_all_editions/