Splitting a Pair of Aces

The rules of blackjack dictate that when a player is dealt two cards of the same value at the start of a round, they have the option to match their original bet and split the identical cards into two separate hands. Splitting pairs not only increases the entertainment value of the game but also works to the players’ advantage and decreases the house edge, i.e. when executed correctly.

The trouble is most novice players experience difficulties with pairs and often do not know how to play such hands optimally. Misplaying paired Aces is one of the most common mistakes among blackjack rookies which ultimately causes them to lose money in the long term instead of profiting. This article teaches you how to approach a pair of Aces optimally and explains when and why you should refrain from splitting them.

Casino Rules on Splitting Aces

blackjackSplitting Aces is considered a very powerful move on behalf of players, so it is only natural for the house to try and do anything possible to prevent them from taking full advantage of this pair. In the majority of landbased and online blackjack variations, casinos prohibit players from hitting their Aces after a split. Instead, each Ace receives no more than one additional card, similarly to what happens after doubling down.

There are certain online variations of the game, like Microgaming’s Super Fun 21, where players get to enjoy more liberal rules when splitting this particular pair, like doubling down on each Ace and resplitting.

The ability to hit split Aces leads to a reduction of 0.19% in the casino’s advantage whereas that of resplitting them decreases the house edge by 0.08%. That being said, the software developers have compensated for the advantage these moves give the player by changing some of the other rules with more unfavorable ones. Worse of all, you get even money for your blackjacks which gives the casino a monstrous advantage over you.

Another peculiarity of Ace splitting results from the payouts you receive when you are dealt a ten-value card next to a split Ace. You have a two-card total of 21 but this is not treated as a natural in this case because it is not based on your original two-card holding. Instead, it is treated as a multiple-card 21 which returns even money instead of the higher 3-to-2 payout awarded for blackjacks.

An Ace is a good card to start a hand with, which is why most casinos do not allow their players to resplit pairs of Aces. This naturally makes doubling on split Aces impossible which also takes away some of your edge. Now that you have read about all these restrictions, you are probably wondering if splitting pairs of Aces is a good idea at all. It is. In fact, splitting Aces is always a good idea from the perspective of a basic strategy player.

Basic Strategy Players Should Always Split Aces

Basic StrategyThe optimal move for paired Aces is among the simplest ones to learn because it never changes in accordance with the playing conditions, the deck number, and the upcard of the dealer. You inevitably split the pair of Aces regardless of whether you are playing a single-deck H17 game or an eight-deck S17 game. No upcard of the dealer is powerful enough to intimidate you when you start a hand with an Ace.

A pair of Aces is actually a soft hand where the Aces have flexible values of 1 or 11. Thus, the total of the pair can be either 2 or 12 depending on which of the two values you choose. The thing about a 12, soft or hard, is it is not a good enough starting total. On the contrary, players end up busting in many cases with this hand.

Splitting Aces gives you the opportunity to create two brand new hands with a more advantageous starting point of 11. Players are always better off when the first card in their hand has a value of 11. This results in significant gains for them over the long haul which explains why most casinos would impose restrictions on how to play out this soft hand. Regardless of the casino rules for hitting, resplitting and doubling on split Aces, the mathematically correct decision for this hand is to always split.

The ten-value cards outnumber any other card denomination in the deck or shoe. There are four ten-value cards from each of the four suits in a single deck that can help you improve your total to the unbeatable 21 when you start with an Ace.

This corresponds to nearly one-third of the cards which means players stand a good chance of catching a 10 to each split Ace. Suppose you pull two Aces out of a 52-card deck along with a third card to represent that of the dealer, a 7, for example.

What are the odds of you catching a 10 as the next card on each Ace? There are now 49 cards left in the deck and 16 of them have a value of 10, which means the likelihood of you improving to 21 with your first Ace is 16 / 49 * 100 = 32.65%.

A Couple of Exceptions to the Above Rule

Payback PercentageSome gambling authors argue Aces should not always be split and indeed, they are correct. There is one exception to the always-split-Aces rule and it is made for games like European Blackjack where there is no hole card. Here the dealer draws their second card after all patrons have played out their hands.

Certain basic strategy moves have undergone adjustments to accommodate the absence of hole cards. One of the adjustments concerns the pair of Aces against a dealer who starts their hand with an Ace, which, as you saw, is a very powerful card to start a hand with.

Instead of splitting, the strategy recommends hitting your soft 12 against an Ace and splitting against dealer upcards deuce through 10. The logic behind this adjustment is the following: the dealer cannot peek under their Ace for a blackjack after offering insurance – they get their second card only after you have completed your hand.