Positive Variations in Blackjack
The positive variations in blackjack are those rules which increase your chances of winning. I wrote the other day listing the common negative variations in blackjack, but I wanted to list the common positive variations in twenty-one, too. These are the rules you should be looking for when you enter a casino, whether it's a land-based casino or a gambling website. Just as you would search for moments of greater opportunity to win any game, this is what happens when you enter a casino and start searching for a good blackjack games. If you want to look at it another way, finding the tables in a casino with the positive blackjack variations is like finding the gas station in town with the lowest prices on gasoline. Every time you engage in your chosen activity (be it gambling or driving), you're saving money. Learn to find the positive variations in blackjack.
Single Deck Blackjack
The single best positive variation in blackjack is playing with a single deck of cards. The advantage of playing with a single deck is worth 0.48% off the house edge. That's a major difference in the odds. Unfortunately, most casinos make the single-deck blackjack table a rare sight these days. In response to card counters, many casinos started increasing the deck size. These days, you'll find two decks, four decks, five decks, six decks, and occasionally even eight decks used by a casino. While this method's effectiveness tops out around six decks, increasing the decks has a direct correlation to your odds of winning. You might ask why that is.
Having fewer cards in the blackjack deck means that every card which goes off the deck is a more important piece of information. Let's assume you're using a single deck with 52 cards. Every single card which is dealt is just under 2% of the deck, so this gives you about 2% of the information about the makeup of the deck. If an ace is dealt, you know there are only 3 aces left that could be uncovered. In a double-deck of cards, every card dealt is less than 1% of the totality of the card deck. So if an ace is dealt when you're using 2 decks of cards, that means 7 aces still remain in the deck. While it's still good information to know, the information isn't nearly as pivotal. The more decks you see, the less meaningful the information you receive is.
Increasing deck size is especially important for card counters. Many methods of counting cards have been devised, but one basic system has you at +1 if a card between 2 and 6 is dealt. If a card equally 10 or 11 is dealt, you subtract -1 from your count. Seven through nine isn't counted for or against. When the numbers are in the positives, you know that's a good time to bet larger amounts, so you increase your bets. This method of determining when it's good to bet is virtually useless when you reach 6 or more decks, and is harmed with each new deck added after one. The number of decks used are posted in an online or land-based blackjack game, but there's an easier way to spot it. If a shoe device is being used, that usually means two or more decks are being used. If the dealer is manipulating the cards the way you would dealing cards at your kitchen table, then you're probably seeing single deck blackjack.
Early Surrender against Ten
When the casino lets you have early surrender against a 10, this increases your expected return 0.24% or lowers the house edge by 0.24%. Surrender is allowed in some games of blackjack when the dealer is showing the possibility of hitting a natural blackjack. If the dealer's upcard is worth 10, then the dealer has a chance of hitting a natural blackjack and beating any possible hand combination you could make besides a natural blackjack (which would be a push). In these cases, it might be smart to surrender. Surrendering lets you take back half of your original wager, while conceding defeat on the hand. This protects your bets in a precarious spot of the game. Early surrender is when you get to make this decision early in the hand, before the dealer is allowed to check for an "ace".
Late surrender is when you can concede, but only after the dealer checks for an ace. Since late surrender eliminates the worst situation which could happen to you, it's an inferior rule to early surrender. Late surrender saves you 0.08% off the house edge. Unfortunately, surrender isn't offered everywhere, especially early surrender rules.
Surrendering goes against the instincts of most gamblers, because they are giving up on the hand. Still, early surrender saves you money--at least when you know how to do it right. Most players surrender too often when the rule is allowed, so read a good strategy chart tailored for surrendering rules before you play a game with early surrender.
Player May Double on Any Cards
When the casino has no restrictions in regards to doubling, this provides a positive variation of 0.23%. Doubling your bet lets you pick and choose which hands you consider the most important ones. When you believe you have an advantage in a hand, you can suddenly double your bet. In the right situation, this increases your expected return significantly, because you press the bet when you have the advantage, not the casino. Having no restrictions on the doubled bets is the third most profitable positive variation you can find.
Six Card Charlie Rule
The six card Charlie rule is the most common of several "Charlie rules". A charlie rule stipulates that you win a hand, no matter what your total, if you reach a certain number of cards without busting. The most common charlie rules stipulate either 5, 6, or 7 cards. The five-card Charlie rule lowers the house edge by a whopping 1.46%, but is rare outside of games like pontoon. The seven-card Charlie rule lowers the house edge by a tiny 0.01%. Since it splits the difference, the six-card Charlie rule's positive variations of 0.16% is often chosen as the Charlie rule of preference.