Shuffling machines have to be carefully designed, as they can generate biased shuffles otherwise: the most recent shuffling machines are computer-controlled. The randomness or otherwise of cards produced from automatic shuffling machines is the subject of considerable interest to both gamblers and casinos. Shuffling machines come in two main varieties: continuous shuffling machines (CSMs), which shuffle one or more packs continuously, and batch shufflers or automatic shuffling machines (ASMs), which shuffle an entire single pack in a single operation.
Batch shufflers are more expensive, but can avoid the problems associated with some continuous shufflers, whereby the shuffling operation only slowly changes the state of the deck, and new cards may be taken before shuffling has sufficiently randomized the pack, allowing some players to “shuffle track” cards through the shuffling process. (資料來源)
