这个时代，你将很难找到一个赌场提供单副牌的二十一点游戏，尤其内置到软件的自动分牌的网上赌场。但在开始单副牌二十一点游戏之前，你需要检查该游戏规则。

　　当然，一个单副牌二十一点游戏比多副牌二十一游戏更有利。两副牌的二十一点游戏与单副牌的二十一点游戏提高了0.35％的游戏障碍。如果是8副牌的二十一点游戏，你的游戏障碍将提高近0.6％。对于任何人熟悉二十一点战略的玩家来说，提高0.1%，意味着提高10%的游戏难度。

　　赌场喜欢常用的一个伎俩是使用6:5的支付比例，而不是标准的3:2 。支付10美元的赌注，6:5将支付12美元，3:2将支付 15美元。12美元与15美元差距并不大，也许你会把对此不以为然，但这往往是赌场坐庄的优势体现。如果你玩高额注的二十一点游戏，6:5的支付比例与3:2 的支付比例之间的区别就很大了。如果你在一个小时内玩多手二十一点游戏，这区别将会扩大。比如8副牌的二十一点游戏，玩家将获得的3.50美元每小时，而不是 8.35美元每小时。所以，如果你在选择发挥多副牌的二十一点游戏，建议你选择一个提供6:5支付比例的网上赌场。

　　玩二十一点，需要运用一些数学思维，要想提高21点游戏的获胜几率，应该选择最少副牌的二十一点游戏。增加一副牌，二十一点的游戏障碍就增加一倍。

　　译文

　　This day and age you would be hard pressed to find a casino offering single deck blackjack. In other words, before jumping into a single-deck game of blackjack, you need to check the rules.

　　Certainly, playing with a single deck is more advantageous than multiple decks. In terms of handicap, two decks versus one deck raises your disadvantage by .35%. Play with 8 decks and your handicap is raised by almost .6%.  For anybody familiar with blackjack strategy, every tenth of a percent counts. But the question remains, is this small gain worth it? Well, not if you are getting paid 6:5 for a blackjack.

　　A common trick that casinos like to employ is to offer 6:5 for a blackjack （natural 21） instead of the standard 3:2. In terms of payout on a $10 bet, 6:5 would pay $12 and 3:2 would pay $15. Fifteen bucks doesn't sound like much, but you wouldn't believe what this does to your overall odds and the Casinos Edge. Instead of a reasonable .58% Casinos Edge playing eight-deck blackjack with a 3:2 "natural 21" payout, a single deck game with a 6:5 payout on a hand of blackjack comes with a 1.4% Casinos Edge - a huge difference!

　　Expanding this even further, if you were to play 60 hands per hour （a low estimate when playing at an online casino）， the expected loss on the 3:2 eight-deck game using perfect strategy would be $3.50/hour, as opposed to $8.35/hour on the 6:5 single-deck game. You can see why you should never play a game of blackjack that pays 6:5. Be careful because some casinos will even advertise it like it's better than 3:2.

　　Before you play blackjack, know your math, and pick blackjack games that have the fewest decks, allow early and late surrender, doubling down on any two cards （including after splitting pairs）， allow multiple pair splitting, re-splitting of Aces.