Being successful at blackjack is about strategy. You have to have one. The whole purpose of strategy in blackjack is to lower the house’s edge. Lowering the house’s edge decreases their chances of winning money from you; and the lower the house edge goes, the more your own blackjack odds go up.
Odds in blackjack are about opportunities to make money. If you have more opportunities to win money or opportunities to win more money than normal, your blackjack odds will increase. Strategy is supposed to decrease the house’s odds and increase your own.
The game of blackjack actually has a couple of parts built into the rules that can increase your blackjack odds and hit the house’s edge: doubling down and splitting pairs.
Doubling down is when you double the amount of your wager and only take one more card. This play can usually only be made at the beginning of your turn. If you win the round, you receive double what you would have made normally off of winning one hand.
Doubling down hits the house edge for 1.6%. This is because this play opens up the opportunity for you to make more money off of the house in one turn than normal.
Another play built into blackjack that will hit the house’s edge is pair splitting. This can happen when you are dealt two of the same card, such as two 3s. You can double your wager and the two cards will be split and each will receive a new second card. This gives you two hands to play in one round.
While not as advantageous—because you can win one hand and lose the other causing a draw—as doubling down, pair splitting can hit the house edge for 0.06%.
Both plays are useful when playing blackjack because of the increase in your chances to win money from the casino. Using them when playing blackjack is important to your blackjack strategy because of the opportunities they give you in terms of decreasing the houses edge.