French card historian Thierry Depaulis debunks this story, showing that prospectors during the Klondike Gold Rush (1896–99) gave the name blackjack to the game of American vingt-un, the bonus being the usual ace and any 10-point card. Since blackjack also refers to the mineral zincblende, which was often associated with gold or silver deposits, he suggests that the mineral name was transferred by prospectors to the top bonus hand. He could not find any historical evidence for a special bonus for having the combination of an ace and a black jack.(資料來源 )
Blackjack games usually offer a side bet called insurance, which may be placed when the dealer’s face-up card is an ace. Additional side bets, such as “Dealer Match” which pays when the player’s cards match the dealer’s up card, are also sometimes available. (資料來源 )