Atlassino Academy · Blackjack · Lesson 9

Pairs: when to split

Splitting a pair puts a second bet of the same size on the felt, so every pair is a question about money — answered here for the rules Lotería de Córdoba publishes for Córdoba casinos.

  • About 15 minutes
  • Illustrated hosts: Leo and Maya
  • Last checked 25 October 2026

Lesson 9 of the blackjack track. You need one thing from earlier: that a pair can be split, and that splitting it is your move; Hit, stand, double, split has the moves. Here, pair by pair: which ones you split at Córdoba tables, which you leave alone, and what the other answer costs.

You are dealt two 8s. The dealer shows a 10, and the dealer’s second card lies face down. Do you split them?

The short answer

Split aces against every dealer card but an ace, and 8s against a 2 to 9. Never split 10s, 5s or 4s. Split 2s and 7s against a 2 to 7, 3s against a 3 to 7, and 6s against a 2 to 6. Two 9s: split against a 2 to 6, an 8 and a 9; stand against a 7, a 10 and an ace. Against a 10 or an ace the 8s and the aces take a card instead: the dealer’s face-down card is turned after you play, and a dealer blackjack takes the split bet too.

Maya holds a second chip over the bare felt beside the betting circle where a chip already lies, while Leo watches from the rail; a pair of eights lies face up in front of the seat with the dealer’s seven across from it.

A split costs a second bet

Two cards of the same value can be pulled apart and played as two hands. You pay for the second hand: a bet the same size as the first, put on the second card.

8888

One hand of 16, one bet.

88

First hand, first bet.

88

Second hand, second bet.

Split two 8s and the 16 is gone. Each 8 starts a hand of its own, and the second one has to be paid for.
  • One split a hand. If a split hand comes out as another pair, it stays as it is.
  • Split aces take one card each in the PBA rulebook. The Córdoba rules do not say how many; the figures here assume one, the same.
  • After a split, an ace and a ten is a 21, not a blackjack, at Córdoba tables: it is paid 1 to 1.
  • A dealer blackjack takes the split bet too. The dealer’s second card is turned over after you play, and its blackjack takes every bet on your hand.

How often a pair turns up

Out of an eight-deck shoe
You are dealtHow often
A pair of any kind14.6% of hands, one in 6.9
Two ten-value cards9.4% of hands, and 64.5% of all pairs
Two of one named rank, say two 8s0.57% of hands, one in 174

So the pair you see most is the pair you never split, and the two worth knowing cold come round rarely enough that you want the answer ready first.

The pairs chart

Eight decks · the dealer stands on every 17 · blackjack pays 3 to 2 · double on 11 only · one split a hand · the dealer’s second card is turned after you play · house edge 2.08% with the full chart, hard totals and soft hands included

Pairs, rules published by Lotería de Córdoba for Córdoba casinos
Pair2345678910A
2,2PPPPPPHHHH
3,3HPPPPPHHHH
4,4HHHHHHHHHH
5,5HHHHHHHHHH
6,6PPPPPHHHHH
7,7PPPPPPHHHH
8,8PPPPPPPPHH
9,9PPPPPSPPSS
10,10SSSSSSSSSS
A,APPPPPPPPPH
  • Psplit
  • Sstand
  • Hhit

Find your pair down the left and the dealer’s card across the column headings. Two 5s sit there as a hard 10, because that is what they are, and at these tables a 10 is not doubled.

The PBA and Entre Rios rulebooks answer a few squares differently; the practice table below switches between all three, and One game, three rulebooks sets them side by side.

Amounts are in betting units, not pesos: a unit can stand for any amount, and the arithmetic is the same at any scale.

The rows with nothing to decide

AAAA

Split, but not against an ace

Together, a poor hand. Apart, two hands that each start on 11, worth having against every card up to a 10.

8888

Split against a 2 to 9

Together, a 16, the total nobody wants. Apart, two hands starting on 8, and almost any card helps an 8. Against a 10 or an ace, take a card.

KKKKKK

Never split

A 20. You stand on it against every dealer card there is.

5555

Never split

Read the total, not the pair: two 5s are a hard 10. The rules allow a double only on 11, so a 10 takes a card against every dealer card.

Two 4s join them at these tables: a hard 8 takes a card against every dealer card, and splitting it is never the answer here.

The small pairs

Four rows are left, and on each of them the dealer’s card decides.

Split only against the cards named. Against anything else, take a card.
You holdSplit when the dealer shows
Two 2s2 to 7
Two 3s3 to 7
Two 6s2 to 6
Two 7s2 to 7

They go apart not because two small hands are good, but because of what lands on them next. A 2, 3, 6 or 7 is a fine card to start on against a weak dealer card: the dealer goes over 21 often, and two hands collect when that happens. Against an 8 and above the dealer finishes strongly too often, and the second bet stays in your pocket.

Against a 10 or an ace

At Córdoba tables the dealer takes a second card face down at the deal and turns it over only once every player has finished. If it makes a blackjack, it takes every bet on your hand, the split bet as well. Against a 10 or an ace that is a real chance, and it turns three squares of the chart.

What the chart says, by what a dealer blackjack takes
You holdAt Córdoba tablesIf it took only your first bet
Two 8s against a 10Take a card: −5.72 units a handSplit
Two 8s against an aceTake a card: −6.65 units a handSplit
Two aces against an aceTake a card: −4.52 units a handSplit

The right-hand column is not a guess: in the PBA rulebook a dealer blackjack takes only your first bet, and there the chart splits 8s and aces against every dealer card. The Entre Rios guide does not say what a dealer blackjack takes from a split hand; the practice table counts the dearer reading for it, every bet.

Splitting two 8s against an ace anyway costs 2.22 units a hand here; against a 10, 0.39 units. Every answer on these squares loses on average: the chart only picks the smallest loss.

One split, and no more

If a split hand comes out as another pair, it stays as it is: the Córdoba rules allow one split a hand, and so does the PBA rulebook. The Entre Rios guide names no limit.

And the limit moves the price without moving one square of your chart. Solve the same rules with four hands allowed: all hundred squares come back the same, and the house keeps 2.04% of every bet instead of 2.08%. When you compare two tables, put this line near the bottom.

Ace and ten on a split ace

Split two aces and draw a ten on one of them, and the rulebooks part. At Córdoba tables the hand is a 21 paid 1 to 1, not a blackjack; the Entre Rios guide says the same. The PBA rulebook pays it 150% of the bet, as a blackjack.

It changes no square of the pairs chart: aces are split against the same cards either way. It changes the price. Paid 150%, the same Córdoba rules would leave the house 1.89% of every bet instead of 2.08%.

Three wrong answers, and what each costs

Amounts are for an example bet of 10 units; at twice the bet, twice the cost.

8888vs77
Not splitting what the chart splits

Leaving two 8s together against a 7

6.75 units

every time you stand on that 16. Split it and the average moves from −4.79 units a hand to +1.96 units, with twice the money on the hand.

Fix: against a 2 to 9, the 8s go apart without thinking.

KKKKKKvs66
Splitting what the chart stands on

Splitting two 10s against a weak card

1.34 units

every time you split them against a 6. The 20 is +7.03 units a hand, two hands starting on 10 are +5.69 units. A weak dealer card does not make your strong hand worse.

Fix: two ten-value cards stand against all ten dealer cards.

8888vsAA
The habit from other tables

Splitting two 8s against an ace

2.22 units

every time you split them against an ace, where a dealer blackjack would take both bets. Against a 10, 0.39 units.

Fix: against a 10 or an ace, take a card.

Rarer ones, though not all of them small: splitting two 5s against a 9 costs 6.47 units a hand; a card on two 6s against a 6, 2.02 units; on two 7s against a 7, 2.20 units. Standing on two 9s against a 6, 1.59 units; splitting them against a 7, 0.31 units.

At the table, with Maya

  • The second bet is the same as the first. Not more and not less: the rules set it.
  • One split, then play the hands. A second pair on a split hand is played as it stands.
  • Remember the face-down card. Against a 10 or an ace the dealer’s blackjack is still to come when you decide, and at Córdoba tables it takes every bet on your hand.

What the chart does to the price

Play the whole chart, hard totals, soft hands and the pairs here, and these Córdoba rules still keep about 2.08% of every bet for the house. The chart lowers the price of playing. It does not take the price away.

Some squares here have a positive average: two 8s split against a 7 come out at +1.96 units a hand, over many thousands of hands. But a pair is dealt to you only now and then, and the whole chart still leaves the house about 2.08%. A good square is not an evening, and it is not a plan.

Maya with a hand on her chest, speaking gently and seriously.

Mayaformer floor supervisor · manners, money and breaks

Splitting doubles what is at risk on the hand. It makes the hand cheaper, not safe, and there is no square here to reach for because the last hand went badly.

Decide your time and your money before you sit down, and keep to them whether the pairs came or not. If the money on the table starts to feel like money you need, stop and call one of the lines below.

If it stops being fun

If gambling stops being entertainment, help is available. Minimum entry age: each province sets its own. Where we found the rule or regulator that sets it, we cite it on the page; those we found set it at 18. More on responsible gaming.

Show all provinces
0800-666-6006Buenos Aires City (CABA) · Línea de orientación por juego problemático (LOTBA) · Monday to Friday, 9 to 17
0800-444-4000Buenos Aires Province · Programa de Prevención y Asistencia al Juego Compulsivo (IPLyC)
0800-777-2983Cordoba · Línea 0800-777-AYUDA (Lotería de Córdoba) · 24 hours
0800-268-5640Santa Fe · Línea gratuita de la APRECOD (Santa Fe) · Every day, 8 to 24
0800-888-2202Entre Rios · Departamento Juego Responsable (IAFAS, PREVENJUEGO)
0261-424-7536Mendoza · Programa de Juego Responsable (IPJyC) · Monday to Friday, 8 to 14
0800-888-5836Misiones · Programa de Juego Responsable del IPLyC S.E. (0800-888-LUDO)
0800-888-2008Chaco · Línea de Juego Responsable (Lotería Chaqueña)
0299-403-8900Neuquen · Líneas de contacto, orientación y tratamiento (IJAN, juego responsable) · Monday to Friday, 8 to 15
0800-222-1700Rio Negro · Línea de Orientación al Jugador Problemático (Lotería de Río Negro)
02901-433515Tierra del Fuego · Departamento Juego Responsable (IPRA, Ushuaia)
0800-555-7678Tucuman · Juego Responsable, Ley 8986 (Caja Popular de Ahorros)
0800-999-1314San Juan · Línea gratuita del Programa Provincial de Juego Responsable (Caja de Acción Social) · Monday to Friday, 08 to 12

If you are thinking about suicide, call 135 or 0800 345 1435 from anywhere in the country

Practice table

Pairs and nothing else, on three levels, with the three rulebooks on a switch above the table. Every answer is the square of the chart for the rules you pick, so the squares that change from rulebook to rulebook change here too, and you can watch it happen. Amounts are for an example bet of 10 units, an example and not a suggested bet.

The practice table needs JavaScript. Here is one hand from it, with the answer.

Eight decks · dealer stands on every 17 · double on 11 only · one split a hand · ace and ten on a split ace pays 1 to 1 · a dealer blackjack takes every bet on the hand

Two 8s against a 7. Together they are a 16, and the dealer is showing a card that finishes strongly. What now?

The chart says: Split.

  • Split them Yes. One 16 becomes two hands that start on 8, and the average result moves from −4.79 units for standing to +1.96 units.
  • Stand on 16 A 16 that stands is paid only when the dealer goes over 21, and against a 7 that is not often. It costs 6.75 units a hand.
  • Take a card Better than standing, and still 6.06 units a hand worse than splitting. A card that helps a 16 is a 5 or less; a card that helps an 8 is almost anything.

Two hands that start on 8 against a dealer 7 are worth more than one 16. The split also puts a second bet on the felt, and that bet can lose too.

The practice table deals these hands on three levels, and the answer to every hand is the square of the chart for the rules you pick.

How the practice table works

One strip, no rounds. Every square on the strip is one hand of this lesson, and they are all there from the start. The square keeps your first answer; when a level’s squares are full the next level begins by itself, with no button in between.

The answers. Every hand is a square of the chart for the rules you picked, read from the engine, not written down beside the hand. The moves offered follow those rules too: a double on two 5s appears only where the rulebook allows a double on 10.

Practice. A hand answered against the chart goes on your list. Practising deals those again; answering one correctly takes it off. Practice does not change the count: only first answers do.

Levels. Level 1: aces and 8s against a middle card, two ten-value cards, and two 5s, which are a hard 10. Level 2: 2s, 3s, 4s, 6s and 7s, where the dealer’s card decides. Level 3: the 9s row, and 8s and aces against a 10 or an ace under each set of rules.

Check yourself

Maya with a finger raised and a knowing look.

Mayaformer floor supervisor · manners, money and breaks

Five quick ones. Pick an answer, then check it. No timer, no points: just whether it stuck.

A question marked “New situation” asks you to use the lesson on a case it did not show.

1You hold two 8s. The dealer shows a 7. What does the chart say?

Show the answer

Answer: Split: put up a second bet and play two hands. Two 8s are a 16, and a 16 that stands is paid only when the dealer goes over 21: on a 7, 26.2% of hands. Split them and each 8 starts a hand of its own: the average moves from −4.79 units to +1.96 units. It also puts a second bet of the same size on the felt.

  • Split: put up a second bet and play two hands Standing keeps one 16 against a dealer card that finishes strongly. Two hands that start on 8 do better by 6.75 units a hand.
  • Hit: take one card and hope Better than standing, and still 6.06 units a hand behind splitting. A card that helps a 16 is a 5 or less; a card that helps an 8 is almost anything.
  • Stand: 16 is something, two 8s are nothing A 16 that stands is paid only when the dealer goes over 21, and a 7 does that on 26.2% of hands. Standing here costs 6.75 units a hand.
2At a Córdoba table you hold two 8s. The dealer shows a 10, with the second card face down. What does the chart say?

Show the answer

Answer: Take a card. The dealer’s second card stays face down until every player has finished, and a dealer blackjack then takes every bet on your hand, the split bet included. Against a 10 that turns the split into the dearer answer, and the chart takes a card instead.

  • Stand on 16 Close behind, and still behind: standing costs 0.02 units a hand against taking a card.
  • Take a card Every answer here loses on average, and taking a card loses least: −5.72 units a hand.
  • Split: 8s are always split At many tables elsewhere, yes. Here the dealer’s second card is turned over after you play, and a dealer blackjack takes the split bet too: splitting costs 0.39 units a hand against the chart.
3At a Córdoba table you split two aces. On the first ace you are dealt a king. What are you holding?

Show the answer

Answer: Twenty-one, paid 1 to 1. A 21 on two cards, paid 1 to 1: the Córdoba rules pay a blackjack on a split ace as a plain 21. The PBA rulebook pays the same hand 150% of the bet.

  • Twenty-one, paid 1 to 1 Right, at Córdoba tables. An ace and a ten on a split ace is paid as a plain 21.
  • A blackjack, paid 150% of the bet That is how the PBA rulebook pays it, not the Córdoba one.
  • Twenty-one, and you may take another card if you like Twenty-one is as high as a hand goes; another card can only take it over.
4You split two 8s, and the first hand is dealt another 8. May you split again?

Show the answer

Answer: No: one split a hand, and the second pair stays as it is. No: one split a hand. And the limit costs you less than it looks. Solve the same rules with four hands allowed and not one square of the chart moves; the house keeps 2.04% of every bet instead of 2.08%.

  • Only if the dealer agrees The dealer follows the rulebook, and the rulebook allows one split a hand.
  • No: one split a hand, and the second pair stays as it is Right. The rules allow one split a hand.
  • Yes, up to four hands Four hands is a rule at many tables elsewhere. The Córdoba rules allow one split a hand.
5You sit down with a plan for the evening and the pairs chart in your head. Over an evening, what has the chart done? new situation

Show the answer

Answer: It has lowered the average price of playing, and changed nothing about one evening. The chart lowers the average price of playing, and that is all it does. Played in full, hard totals, soft hands and pairs, these rules still keep 2.08% of every bet for the house: about 15 units an hour at 70 hands and 10 units a hand, averaged over many evenings. One square with a positive average does not change that, and one evening lands far from the average in both directions.

  • It has told you how much to put on each hand The chart says which move, never how much. The one thing it says about money is that a split is a second bet of the same size, set by the rules, not by you.
  • It has lowered the average price of playing, and changed nothing about one evening That is exactly what it does: about 15 units an hour at 70 hands and 10 units a hand, on average, over many evenings. One evening lands far from that in both directions.
  • It has taken the house edge off those hands The chart lowers the price; it does not remove it. Playing every hand by the chart still does not decide how one evening ends.
  • It has turned the pairs into money: the 8s against a 7 average a gain One square can have a positive average and the evening can still cost you. Played by the whole chart, these rules leave the house 2.08% of every bet.

And the question we opened with

Two 8s against a 10 at a Córdoba table: no, you take a card. Every answer on that square loses on average, −5.72 units a hand for the card and −6.11 units for the split, because a dealer blackjack, turned over after you play, would take the second bet as well.

Where to play, and further reading

18+ under each province’s rules · Play responsibly · the helplines are further up this page

Further reading

How it’s worked out

Rules, numbers and hosts

Rules. The figures on this page follow the rules Lotería de Córdoba publishes for Córdoba casinos: at least eight decks (the figures take exactly eight), the dealer standing on every 17, blackjack paid 3 to 2, a double only on a two-card 11, one split a hand, an ace and a ten on a split ace paid 1 to 1, and a dealer’s second card turned over after the players, whose blackjack takes every bet on the hand. The rulebook does not say whether a split hand may be doubled or how many cards a split ace takes; the figures assume a double on 11 after a split and one card on each split ace. It is a preset for learning, not a statement about any one casino: the room settles anything its rulebook leaves open.

Numbers. Every figure on this page is worked out when the page is built, by our blackjack engine. For each pair and each dealer card the engine averages every way the hand can go, including the hands that follow a split, and the chart shows the move with the higher average result. A mistake’s cost is the average result of the chart’s move minus that of the mistake, per hand, for an example bet of 10 units, with each average rounded to the hundredth first. Against a 10 or an ace the averages include the hands where the dealer turns up a blackjack. How often a pair comes is arithmetic on an eight-deck shoe. The house edge assumes the full chart, hard totals, soft hands and pairs, and cards shuffled after every hand.

Hosts. Leo and Maya are illustrated characters. Their backstories, a former dealer and a former floor supervisor, are written for the course: neither is a real person, and neither speaks for any casino. The rules and numbers on this page come from the sources it cites, not from their experience.

No promise. Blackjack is played against the house. The chart lowers the price of playing; nothing on this page removes that price or tells you how an evening will end.

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