Should You Split This Pair?

Four of us were at the blackjack table. First base had a pair of deuces against the dealer's deuce up. He looked around the table with a quizzical expression on his face. "Split'em", advised the player at third base. "No, not against a deuce", commented another. The player held his up finger and asked the dealer to wait a second. He went into his shirt pocket and consulted a strategy card, then just tapped on the table for a hit.

After he lost the hand, third base again chimed in with, "You really were supposed to split those, ya' know." The player replied, "Not according to my cheat sheet", as he pulled his pre-printed card out of his pocket and pointed to the line where it read, "Split 2s against 4 thru 7 up."

Third base replied, "That's interesting", as he took a multi-colored chart out of his wallet and tossed it over to first base. It clearly had a pair of deuces colored bright yellow all the way from a dealer's 2 thru 7 up, meaning that 2s against a 2 should be split.

Both these players appeared to be holding legitimately published basic strategy cards. So then, why the discrepancy? Do you split a pair of deuces against a dealer's deuce, or don't you?

The answer is that these two charts were probably printed for different sets of blackjack rules. The one rule that affects how many pairs should be split is the "Double After Split" rule (DAS). When you can double down on one of your deuces if you catch a good card like an 8 or a 9, then it's worth splitting your deuces against that deuce up. But if you can only double down on your first two cards and not pairs that have been split -- then you're better off just hitting that hand.

That's why there's such confusion over what to do with tricky pairs like a pair of 3s against a 2, or a pair of 4s against a 6. So let's spell all that out right now.

First off, whenever your pair is 7s or higher, it doesn't matter a hoot what the rules are. You should just always split:

7s against 2 thru 7
8s against anything
9s vs. anything except 7, 10, or A
10s never
Aces against anything

Those are easy –- they never change. But when you have those smaller pairs against small dealer up-cards, it depends upon whether you can double down after splitting that pair. Now, most blackjack games these days do allow you to "DAS". So in general, when you have a small pair you should split:

2s against 2 thru 7
3s against 2 thru 7
4s against 5 or 6
5s never
6s against 2 thru 6

A pair of 4s provides the clearest example of the advantage that being allowed to double down after splitting a pair creates. Anybody can see that starting off with a total of 8 (4/4) is better than two totals of 4 each – 8 is simply a better hand than 4. But suppose the dealer has a weak card up like a 5 or a 6 and you split your 4s. Now, if you catch any 5, 6, 7 or Ace on either of your 4s you've got yourself a good double down. However, if the rules don't allow you to DAS, you've lost your reason to split those 4s and should just hit it.

So when you cannot DAS, simply hit:

2s against a 2 or 3
3s against a 2 or 3
4s against a 5 or 6
6s against a deuce

When you can DAS, 52 out of 100 possible pairs should be split. If you can't DAS, then you should split only 45 of them. Don't sweat it too much though. You'll be dealt one of those seven decisive pairs only once every 325 hands, combined. If you always play them wrong, it'll cost a $15 bettor an average of 12 cents per hour (0.01% overall). So if you can't remember the particulars, just go with the more common "DAS" rules.