How does online poker work?

Question

I'm talking about the programming, math, randomness of computer dealing. Not rules, etc.

Answer 1

Every site is different of course, but the basic programming works one of three ways:

1) On not-so-good sites, they have predetermined hands stored in an array and pick one at "random".  i.e. they'd have the hole cards, flop, turn and river all set and play it out when that hand is run.

2) Better sites will either determine each card played in random as they come up (i.e. player to dealer's left gets any card out of 52, next player gets any card out of the 51 left when first card went out etc).  In these cases, the program basically has an array of a "clean deck" and will mark cards as "played" when they are dealt (or burned) and chose at random from the unplayed cards each time a card is needed.

OR

3) Some will predetermine the order of the deck first (i.e. virtual shuffle) and store the cards in that order in an array and then simply play them as they go.  Keeping in mind that they only need 25 cards in total (if it's a 10 player Texas hold 'em table).  This is a little faster since once the "shuffle" happens there's no more randomization.  If you're a traditionalist, you'll have the program determine 28 cards so the "burn" cards are actually considered even though they are never seen or used.