While at the blackjack table, you will inevitably find yourself in situations where the dealer deals you starting hands consisting of paired cards, i.e., two cards of the same numerical value. It is ultimately your decision how to play the hand. In the vast majority of cases, you will have the option to split the pair after doubling your initial stake.
In the event of splitting, the dealer will separate the pair into two hands and draw one more card on each of the two new hands. You will then play each hand as normal and have the chance to win twice as much as you otherwise would.
The most commonly occurring pair in blackjack consists of 10s for the simple reason that the cards assigned a value of 10 outnumber any other card denomination in the deck. A single deck contains 16 of those: four 10s, four Jacks, four Queens, and four Kings. A pair of 10s makes for a very strong hand of 20, which can be beaten only if the dealer has a blackjack or a total of 21.
There are three types of players who may venture to split this pair: blackjack novices who have not yet learned basic strategy, tournament players, and those who have mastered card counting. This article discusses the reasons why splitting 10s is detrimental to basic-strategy players and advantageous for professionals.
Playing Decisions with a Pair of 10s
When players are dealt a pair of 10s, they have only two options: to stand or to split. Doubling, hitting, and surrendering do not make the cut for obvious reasons. If the player chooses to stand on this pair, they end up with a hard total of 20. This is almost impossible to beat unless the dealer has a blackjack or draws to 21.
If the player splits, they form two separate hands, and each one starts with a 10. In most land-based and online variations of the game, players are allowed to resplit, usually up to two times, so that they can form four separate hands during a single round of play.
If, for example, you split Q-K and receive another Queen on one of your split hands, you will be allowed to resplit again, making three hands, each starting with a ten-value card. Which is the optimal decision according to basic strategy?
Why Casual Players Should Never Split 10s
Some recreational players split this pair regardless of the dealer’s upcard. Others choose to split pairs of 10s only when the dealer is at a disadvantage, showing small cards like 5 and 6. Their reasoning goes something like this: “The dealer is going to bust with this 5 or 6, so let me split the 10s. I can make two great hands instead of one and double my profits.”
Neither decision is optimal in the long run, though. Suppose you are playing six-deck blackjack where the dealer is required to stand on soft totals of 17. You are dealt a pair of 10s, and the dealer ends up with a 5 as the upcard.
If you choose to stand on the pair of ten-value cards, you win 84 out of every hundred hands and lose the remaining 16 on average. We exclude cases where you and the dealer push. This makes sense because a total of 20 is difficult to beat, especially by a dealer who starts at a disadvantage with a 5 or 6 as their upcard.
Your expected value decreases when you consistently split the pair of 10s against the 5. When you split, you win only 63 out of every hundred hands and lose the other 37 on average. The decrease in profits is considerable because players who split their 10s often end up with two weaker hands whose totals are below 20.
Why Casual Players Should Never Split 10s – Additional TipsIf you flat bet $1, your average long-term profits when you stand on your 10s over the course of a hundred hands amount to $84 – $16 = $68. But if you split the 10s, you will experience a decrease in your average profits per hundred hands of $63 – $37 = $26 * 2 = $52. As you can see, splitting the 10s against the dealer’s 5, compared with standing, will cost you $16 on average.
Similarly, if you decide to split the 10s against a dealer with a 6 as the upcard, you are bound to win 64 out of every hundred hands and lose the remaining 36 on average. You end up earning average profits of $64 – $36 = $28 * 2 = $56.
However, if you decide to stand against the 6 instead, you will win 85 out of every hundred hands and lose the other 15 on average, which means you will net profits of $85 – $15 = $70 over the long run. This results in a $14 drop in your average profits if you consistently split the 10s against the 6 instead of standing.
It should be noted that basic strategy favors standing over splitting the 10s regardless of the number of decks in play, the dealer’s upcard, or their fixed standing rules. You will inevitably arrive at the conclusion that standing on the pair of 10s yields more profits than splitting in the long term.
More importantly, if splitting was a bad decision in the first place, so is resplitting when you happen to catch another 10 on the draw. The bottom line is that basic-strategy players should refrain altogether from splitting pairs of 10s and instead settle for a hard 20.
A Few Exceptions to the Above Rule
There is a saying in blackjack circles which states that only clueless players and card counters ever split 10s, and indeed, there is some truth to this statement. But why is splitting 10s detrimental to the former and advantageous for the latter?
Unlike casual players, card counters are able to keep track of the ratio of high cards to low cards in the remaining deck or shoe. They sometimes split a pair of 10s when the dealer shows weak upcards like 5 and 6, but only if the shoe composition allows it and many ten-value cards remain to be dealt.
Splitting becomes a good idea under these circumstances because the player is more likely to catch ten-value cards and form two totals of 20 (or potentially draw some Aces for even better totals of 21).
Additionally, when the shoe is rich in ten-value cards, the dealer becomes even more susceptible to busting with their 5 or 6. This is so because high cards are generally detrimental to the blackjack dealer. When there is an excess of ten-value cards in the shoe, advantage swings to the player and vice versa. If the small cards in the remaining shoe outnumber the high ones, the house has an edge over the players.
Additional ExceptionsProvided that you are using a popular card-counting system like the Hi-Lo, you may choose to split pairs of 10s, but only when you have a positive true count of 5 or higher.
Keep in mind that most professional card counters refrain from splitting 10s altogether to avoid detection and barring. This play is viewed with suspicion by dealers and pit bosses alike, so you should not overdo it, especially not during the same gaming session or shift.
Another situation in which splitting 10s offers more value than standing is in blackjack tournaments, particularly during the final round of play. In tournaments, your goal is to beat fellow players by generating more profits than they do within a predetermined number of hands. Splitting your 10s may be the proper course of action when you are trying to catch up with the table’s chip leader and get ahead of them after the last hand.
The crux of the matter is, splitting 10s is a good idea only if you are a skilled card counter or are playing blackjack tournaments. It is never wise for a basic-strategy player to split this pair because doing so reduces their long-term expected value. Standing on your 10s is the optimal strategy decision because it yields the highest profits in the long run.