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Card Counting Glossary: 62 Blackjack Terms in Plain English

Plain-English definitions of the blackjack and card counting terms used in books, forums and this site, from back-off and balanced count to wonging.

By CardCount Academy · Reviewed · 8 min read

Blackjack books and forums use a compact vocabulary that can make simple ideas look complicated. This glossary defines the 62 terms you are most likely to meet, in plain English. Where a term has its own guide, the related reading is listed at the end.

Jump to: A · B · C · D · E · F · H · I · K · L · N · P · R · S · T · U · V · W

A

Ace-neutral count
A counting system that gives the ace a value of 0, such as Omega II or Hi-Opt II. It is better for playing decisions and is usually combined with a separate side count of aces for betting.
Advantage play
Any legal method of playing a casino game with a positive expectation. Card counting is the best-known example.

B

Back-counting
Counting a table from behind without playing, and sitting down only when the count becomes favorable. Also called wonging.
Back-off
When a casino tells a player they may no longer play blackjack there, usually while still allowing other games.
Balanced count
A system whose card values add up to zero over a complete deck, such as Hi-Lo. It needs a true count conversion.
Bankroll
The total amount of money set aside for playing, whose complete loss the player can afford.
Basic strategy
The mathematically best play for every hand against every dealer upcard, assuming no knowledge of the remaining cards.
Bet ramp
The rule that sets the bet size for each true count, rising as the count rises.
Bet spread
The ratio between a player's largest and smallest bets, such as 1–8.
Betting correlation
A measure, from 0 to 1, of how closely a counting system's tags follow each card's real effect on the player's edge. It indicates how well the system sizes bets.
Big player
In team play, the member who places large bets at tables that teammates have identified as favorable.
Burn card
The first card of a new shoe, discarded unseen by the dealer. It is treated like any other unseen card.
Bust
A hand total over 21, which loses immediately.

C

Camouflage
Anything a counter does to look like an ordinary player, usually at some cost in expected value.
Cancellation
A high card and a low card seen together whose tags add up to zero, so the pair can be skipped when counting.
Continuous shuffling machine (CSM)
A device that mixes used cards back in after every round. It makes card counting ineffective.
Cut card
The plastic card placed in the shoe to mark where the dealer will stop and shuffle.

D

DAS
Double after split: the rule allowing a player to double down on a hand formed by splitting a pair.
Deck estimation
Judging by eye how many decks remain to be dealt, normally by looking at the discard tray.
Deviation
A departure from basic strategy that becomes correct at a particular count. Also called an index play.
Discard tray
The holder beside the dealer where used cards are stacked.
Double down
Doubling the original bet in exchange for receiving exactly one more card.

E

Effect of removal
The change in the player's expectation caused by removing one card of a given rank from the deck.
Even money
An offer to pay a player's blackjack 1:1 immediately when the dealer shows an ace. It is mathematically the same as taking insurance.
Expected value (EV)
The average result of a bet or decision over a very large number of repetitions.

F

Fab 4
The four most valuable surrender deviations, identified by Don Schlesinger.
Flat betting
Betting the same amount on every hand.

H

H17
A rule under which the dealer hits soft 17. It adds about 0.2% to the house edge compared with S17.
Hard hand
A hand with no ace, or in which the ace must count as 1.
Heat
Attention from casino staff directed at a suspected advantage player.
Hole card
The dealer's face-down card.
House edge
The average share of the initial bet that the casino expects to keep, assuming correct play.

I

Illustrious 18
The eighteen playing deviations that provide most of the gain available from index plays, published by Don Schlesinger.
Index number
The count at which a particular deviation from basic strategy becomes the better play.
Initial running count (IRC)
The number an unbalanced system starts from after a shuffle. For KO it is 4 minus 4 times the number of decks.
Insurance
A side bet, offered when the dealer shows an ace, that the hole card is a ten. It pays 2:1 and is a losing bet unless the count is high.
Insurance correlation
A measure of how well a counting system predicts when the insurance bet is favorable.

K

Kelly criterion
A formula for the bet size that maximizes long-term bankroll growth: roughly the edge divided by the variance of the bet.
Key count
In an unbalanced system, the running count at which the player first has the advantage and should raise the bet.

L

Level
The largest tag a counting system uses. Level-one systems use only +1 and −1; level two uses up to ±2.

N

N0
The number of hands after which a player's expected win equals one standard deviation — a measure of how long the long run is.
Natural
A two-card 21: an ace with a ten-valued card. Also called a blackjack.

P

Penetration
The proportion of the shoe that is dealt before the shuffle. Deeper penetration favors the counter.
Pivot point
In an unbalanced system, the running count at which the count matches a balanced true count exactly, whatever the number of decks remaining.
Playing efficiency
A measure of how well a counting system identifies the correct playing decision.
Push
A tie between player and dealer. The bet is returned.

R

Risk of ruin
The probability of losing an entire bankroll before it grows, given a fixed way of betting.
Running count
The sum of the tags of every card seen since the shuffle.

S

S17
A rule under which the dealer stands on all 17s, including soft 17. Better for the player than H17.
Shoe
The box from which multiple decks are dealt; by extension, one pass through those decks.
Side count
A second count kept alongside the main one, most often of aces.
Soft hand
A hand containing an ace counted as 11, which cannot bust with one more card.
Spotter
In team play, a member who counts at minimum bets and signals the big player when a table becomes favorable.
Stiff
A hard total from 12 to 16, which can bust with one more card.
Surrender
Giving up half the bet instead of playing the hand. Late surrender is allowed only after the dealer has checked for blackjack.

T

Tag
The value a counting system assigns to a card, such as +1 for a 5 in Hi-Lo.
True count
The running count divided by the number of decks remaining. It is the number used for betting and deviations in a balanced system.

U

Unbalanced count
A system whose card values do not add up to zero over a deck, such as KO or Red 7. It is used directly from the running count.
Unit
A player's minimum bet, used as the measure for bet sizes, bankrolls and results.
Upcard
The dealer's face-up card.

V

Variance
A measure of how widely results swing around their average. Its square root is the standard deviation.

W

Wonging
Entering a game only at favorable counts and leaving at unfavorable ones. Named after the author Stanford Wong.

Where to read more

Educational content only. Card counting does not guarantee winnings, casinos can limit or refuse play, and laws differ by location. Read the disclaimer and, if gambling stops being fun, our responsible gambling page.

Sources and further reading

  • Peter A. Griffin, The Theory of Blackjack (Huntington Press).
  • Don Schlesinger, Blackjack Attack: Playing the Pros' Way (RGE Publishing) — origin of the "Illustrious 18".
  • Stanford Wong, Professional Blackjack (Pi Yee Press).
  • Olaf Vancura and Ken Fuchs, Knock-Out Blackjack (Huntington Press, 1998).
  • Wizard of Odds — Card Counting: Introduction