The Optimal Shuffle

[paulish]

On the DVD Cheating at Hold'em, David Malek gives the following
Optimal Shuffle Sequence:
- -- --- ---- -----
1. Scramble
2. Box
-Cut the top 1/3 of the deck and put it on the bottom
3. Riffle Twice
(Bottom and top card of the deck should change on each riffle)
4. Box
5. Riffle Twice
6. Strip
(Take a portion of the top of the deck and place on table: 4-6 times)
7. Riffle
8. Cut
----- ---- --- -- -

-How does one determine that this Black Jack shuffle is the Optimal Shuffle Sequence?
-You might get a pretty random deck, but at the cost of time. This shuffle is way to slow for use in my home game. How many steps can you delete, between a quick Scramble and the Cut while not giving up to much on the quality of the shuffle?
-Any other standards out there?

paul

[Paul2432]

I don't have an answer to your question, but can offer two suggestions:

1) For home games, use two decks with different color backs. The cards for the next deal can be shuffled while the current deal is in progress.

2) Sort a deck by ranks/suits then shuffle using a method. Do you see lots of clusters of consecutive cards of the same suit? If so, the method is probably inadequate.

Paul

[BYATT34]

Most likely, he is not using the term ‘optimal’ in a rigorous sense. Perhaps in theory you could specify a utility function for the time it takes to perform a shuffle, and another utility function for how much randomness the shuffle has, and then describe an optimal shuffle in the sense that it maximizes your own total utility according to those two utility functions. But I don’t really know if that is practical.

Meanwhile, you could try searching Google on the keywords shuffle and cards. One page that looks reasonable is wikiHow article How to Shuffle and Deal Texas Holdem.