# The Numbers of 21

## ENCYCLOPEDIA OF BLACKJACK

##m##c. Acronym for a balanced side count (#, # minus #, # count).  In otherwords, # and # count +1.  And # and # count -1.  Example: 45m79c.  See books by BJANALYST.

1. One of two values for the ace as declared by the player. If an ace is removed from a single-deck Las Vegas Strip (LVS) rule game it puts the player at a -.61% disadvantage.  See 11.  See Ace.

1.1 – 1.5.  The approximate standard deviation for a single hand in blackjack.

10. A ten valued card which can be a ten, jack, queen, or king. There are 16 ten valued cards in a deck of cards. A card which, if removed from a single-deck LVS rule game puts the player at a 0.51% disadvantage. See ten.

104. The number of cards in a 2-deck game.

11. 1) One of two values for the ace as declared by the player. See 1. See Ace. 2) A great starting hand for the player.  Usually, you will be doubling your bet with this hand. 3) A blackjack side bet.  See Perfect 11’s.

12-16. A stiff or potentially breaking hand.

13. The worst possible hand a triskaidekaphobic1)This was included as one of the test questions at Max Rubin’s annual Blackjack Ball. person can get 🙂

14 Count. See Revere 1973 APC.

17-21. A pat or potentially winning hand.

18.  See Rule of 18.

101012 This is a binary number in base 2.  In base 10, the number becomes 1*16 + 0*8 + 1*4 + 0*2 + 1*1 = 21.  This was seen on the very first issue of 21 News, a rec.gambling.blackjack newsletter from 1990.

1 deck. (1D) See single-deck.

1:X. A bet spread of 1 to X (e.g., 1:6 or 1:8)

2. A low card which, if removed from a single-deck LVS rule game gives the player a +.38% advantage.

208. The number of cards in a 4-deck shoe.

2-6. A stiff card. When the dealer has one of these up-cards the dealer has what is referred to as a potentially stiff hand.

2:1. Abbreviation for a blackjack game in which naturals pay 2 to 1 instead of the normal 3 to 2.  This is often offered in blackjack tournaments to simplify the payoff.

2.7. The average number of cards that are used in a blackjack hand.

21. 1) The best sum of card values a player can obtain. This value is called a blackjack if it is from the player’s original two cards (a ten valued card plus an ace). 2) Surprisingly, the player (and dealer) will receive a blackjack every 21 hands (or so).

21+3. (TP3) A blackjack side-bet available in some casinos.  Several variations exist.  Based on the player’s first two cards “and” the dealer’s up card.  You win this bet if the 3 cards equal a flush, straight, straight flush, or three of a kind. HA ~ 3.24% – 13-4% depending on pay table.

21 Bet. See entry under Bet 21.

21 Burn. See entry under Burn 21.

21 Duel. See entry under Duel 21.

21 Magic. See entry under Magic 21.

21 Stud. See entry under Stud 21.

21 to the River.  See entry under 21 to the River.

22-31. A busted hand.

2 deck. (2D) See two deck.

245. See Rule of 2, 4, and 5.

3. A low card which, if removed from a single-deck LVS rule game, gives the player a +.45% advantage.

34. Look at any blackjack basic strategy card and you can figure there are 34 possible two-card starting hands: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, AA, 22, 33, 44, 55, 66, 77, 88, 99, TT, A2, A3, A4, A5, A6, A7, A8, A9 and AT.  Note that there is only one way to make a 2 (AA), 3 (A2), 20 (TT) and 21 (AT).  The number 34 assumes card order and composition do not matter.

312. The number of cards in a 6-deck shoe.

3:2. Abbreviation for a blackjack game in which naturals pay off the normal 3 to 2.  In other words, a \$10 wager will win \$15 if the player receives a natural and the dealer does not also have a natural 21.  See 6:5.

3 deck. (3D) See three deck.

3up. Acronym for play one hand against 3 dealer up-cards.

4. A low card which, if removed from a single-deck LVS rule game gives the player a +.55% advantage.

416. The number of cards in a 8-deck shoe.

441. Approximately, once every 441 hands both the player and dealer will receive a blackjack at the same time.  A player’s blackjack will push (tie) the dealer’s blackjack.

4 deck. (4D) See four deck.

45. See Rule of 45.

45m79c. Acronym for a balanced side count (Four, Five minus Seven, Nine count).  In otherwords, Fours and Fives count +1.  Sevens and Nines count -1.  See books by BJANALYST.

5. 1) A low card unique in the sense that it can convert all stiff hands into pat hands. It is the most valuable card for the dealer. If removed from a single-deck LVS rule game it gives the player a +.69% advantage. 2) Acronym for Five Card 21 pays 2 to 1.
[ 2) Wong CBN ]

5 deck. (5D) See five deck.

52. The number of cards in a standard deck of playing cards, excluding jokers.

5-5-5-5. A bonus hand offered in some casinos. Typical payoff was 2 to 1.
[92 Wong Basic Blackjack]

6. 1) A low card which, if removed from a single-deck LVS rule game gives the player a +.46% advantage. 2) Acronym for six card un-busted hand wins automatically. 3) See Rule of 6.
[ 2) Wong CBN ]

 WARNING: DANGER AHEAD Don’t play casino twenty-one when the dealer only pays 6 to 5 on a blackjack!   Unless, of course, you can see the dealer’s hole-card.  Norm Wattenberger, author of Casino Verite, sums it up nicely – “If a casino calls a game Blackjack but in small letters says Blackjack pays 6:5, it is a fraud. You should not play 6:5 Blackjack. In my opinion, you should not play any Blackjack at a casino offering this fraud. You should not gamble at all in such a casino, or stay in its hotel or eat in its restaurants.”

6:5.   Abbreviation for a blackjack game in which naturals pay off at 6 to 5. This is a sucker bet. A \$10 wager will win only \$12 if the player receives a natural and the dealer does not also have a natural 21.  House edge for a typical single deck game with the 6:5 rule is about 1.45% 2)In some 6:5 single deck games, a player’s natural wins regardless of what the dealer has — which reduces the house edge in the game slightly to 1.24%.  If you are offered “even money” for your blackjack when a dealer shows an Ace you should take it.  Unlike in a 3:2 game, the player has a slight 0.06% advantage on this play.  Most casinos, however, don’t offer even money in 6:5 games for this reason., compared with 0.18% for a typical single deck game with the normal 3:2 rule.   This is a definitely a rule all players should avoid and protest. A typical \$25 player will lose an “additional” \$25 to \$30 (or so) every hour he/she plays in this game.   See 3:2.  See rule variations.

6-7-8. A popular bonus hand in social blackjack games and in some casinos. Some casinos have experimented with paying players a bonus if they receive this hand suited but only if they win the hand. In other words, the player does not receive the bonus if he ties the dealer or the dealer turns up a natural. Typically, any 6-7-8 pays double or there is a bonus for this hand.  See Royal 21. See 7-7-7.
[ 9/92 Schlesinger Lost in the Maze..BJF ] [ 92 Wong Basic Blackjack ]

68-95-99 rule.  See standard deviation.

6 deck. (6D) See six deck.

7. A card that can be considered a low card or a neutral card. If removed from a single-deck LVS rule game it gives the player a +.28% advantage.

7:5.   Abbreviation for a blackjack game in which naturals pay off at 7 to 5.  This is a sucker bet but not as bad as 6:5. A \$10 wager will win only \$14 if the player receives a natural and the dealer does not also have a natural 21.  See 6:5. See 3:2.

77. The number on virtually every Ace of Spades in a deck of jumbo index casino Bee brand playing cards.  See 92.

7-7-7. See Royal 21.

8. The most neutral of all cards which, if removed from a deck has little or no effect on advantage.

86’d. Abbreviation for being kicked out of a casino and usually with a threat of being arrested if you return.

8 deck. (8D) See eight deck.

9. A card which, if removed from a single-deck LVS rule game puts the player at a 0.18% disadvantage.

92. The number on virtually every Ace of Spades in a deck of standard index casino Bee brand playing cards.  See 77.

 The two exotic rule options above have appeared in the casinos in the following formats:Winning 6-7-8 suited pays 2 to 1Winning 7-7-7 suited pays 3 to 2In each case above the advantage to the player is small (PA = +0.01%). According to Stanford Wong’s Blackjack Analyzer software the only basic strategy change is for the 6-7-8 case where it is correct to hit 6-7 suited versus a dealer 2. [9/92 Schlesinger Lost in the Maze.. BJF]

Footnotes

↑1 This was included as one of the test questions at Max Rubin’s annual Blackjack Ball. In some 6:5 single deck games, a player’s natural wins regardless of what the dealer has — which reduces the house edge in the game slightly to 1.24%.  If you are offered “even money” for your blackjack when a dealer shows an Ace you should take it.  Unlike in a 3:2 game, the player has a slight 0.06% advantage on this play.  Most casinos, however, don’t offer even money in 6:5 games for this reason.