Double Exposure Blackjack
Analyzed by Jeff Jennings, Steve Jacobs

 
Rules
-----

Cards are dealt from 6 decks.
Blackjack payoff is 1:1.
Player blackjack beats dealer blackjack.
House wins all ties.
Dealer must hit soft 17.
Player may double-down on any first two-cards.
Pairs may be split only once.
No double-down allowed after splitting.
Player may take insurance when dealer has ACE showing.
Dealer's hole card is visible.

Overall player advantage: -0.36%

Here is a list of rule changes and it's effect on the above game:

Dealer stands on soft seventeen    +0.4%
Naturals pay 3:2                   +2.3
Tied natural pushes                -0.2
Resplits allowed                   +0.3
Double after splits                -0.3
No split unlike 10s                -0.2
Double on 10 and 11 only           -1.3
Double on 9, 10, 11 only           -0.9


Basic Strategy
--------------


                   Double Exposure 21 Strategy Table

    <--------------- hard dealer hands ----------------->
---+-------------------------------------------------------------------------
     AA A2 A3 A4 A5 A6 4  5  6  7  8  9  10 11 12 13 14 15 16 17 18 19 20 21
---+-------------------------------------------------------------------------
XX | S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  PS PS PS PS S  S  S  h  s
99 | s  s  s  ps ps S  PS PS PS S  ps s  s  s  PS PS PS PS PS S  Ph h  h  s
88 | s  s  s  s  ps ph ps Ps Ps ph ps s  s  s  Ps PS PS PS PS Ph h  h  h  s
77 | s  s  s  s  s  h  s  ps ps h  h  h  s  s  Ps PS PS PS PS ph h  h  h  s
66 | h  h  s  s  s  h  ps ps ps h  h  h  h  h  Ps PS PS PS PS ph h  h  h  s
55 | h  h  DH DH DH H  DH DH DH DH DH H  h  h  DH DH DP DP DP H  H  H  h  s
44 | h  h  h  h  h  h  h  H  H  h  h  h  h  h  PD PD PD PD PD H  h  h  h  s
33 | h  h  h  h  h  h  h  ph Ph h  h  h  h  h  PH PH PD PD PD Ph h  h  h  s
22 | h  h  h  h  h  h  h  ph PH h  h  h  h  h  PH PH PD PD PD PH h  h  h  s
AA | Ph Ph Ph Ph PH Ph PH PH PH PH Ph Ph ph h  PD PD PD PD PD H  H  h  h  s
---+-------------------------------------------------------------------------
AX | S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S
A9 | S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  DS DS DS DS S  S  S  h  s
A8 | S  S  S  S  S  S  S  S  S  S  S  s  s  s  DS DS DS DS DS S  S  h  h  s
A7 | h  h  h  h  h  S  DS DS DS S  h  h  h  h  DS DS DH DH DH S  h  h  h  s
A6 | h  h  h  h  h  h  h  DH DH h  h  h  h  h  DH DH DH DH DH H  h  h  h  s
A5 | h  h  h  h  h  h  h  DH DH h  h  h  h  h  DH DH DH DH DH H  h  h  h  s
A4 | h  h  h  h  h  h  H  H  DH h  h  h  h  h  DH DH DH DH DH H  h  h  h  s
A3 | h  h  h  h  h  h  H  H  DH h  h  h  h  h  DH DH DH DH DH H  H  h  h  s
A2 | h  h  h  h  h  h  H  H  DH H  h  h  h  h  DH DH DH DH DH H  H  h  h  s
AA | h  h  h  h  H  h  H  H  H  H  h  h  h  h  DH DH DH DH DH H  H  h  h  s
---+-------------------------------------------------------------------------
21 | S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S
20 | S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  S  h  s
19 | S  S  S  S  S  S  S  S  S  S  S  s  s  s  S  S  S  S  S  S  S  h  h  s
18 | s  s  s  s  s  S  S  S  S  S  s  s  s  s  S  S  S  S  S  S  h  h  h  s
17 | s  s  s  s  s  h  s  s  s  s  s  s  s  s  s  S  S  S  S  h  h  h  h  s
16 | s  s  s  s  s  h  s  s  s  h  s  s  s  s  s  S  S  S  S  h  h  h  h  s
15 | s  s  s  s  s  h  s  s  s  h  h  h  s  s  s  S  S  S  S  h  h  h  h  s
14 | s  s  s  s  s  h  s  s  s  h  h  h  h  s  s  S  S  S  S  h  h  h  h  s
13 | s  s  s  s  s  h  s  s  s  h  h  h  h  h  s  S  S  S  S  h  h  h  h  s
12 | h  h  s  s  s  h  s  s  s  h  h  h  h  h  s  S  S  S  S  h  h  h  h  s
11 | DH DH DH DH DH DH DH DH DH DH DH DH h  h  DH DH DH DH DH H  H  H  h  s
10 | h  h  DH DH DH H  DH DH DH DH DH H  h  h  DH DH DH DH DH H  H  H  h  s
 9 | h  h  h  h  h  h  DH DH DH H  h  h  h  h  DH DH DH DH DH H  H  h  h  s
 8 | h  h  h  h  h  h  h  H  H  h  h  h  h  h  DH DH DH DH DH H  h  h  h  s
 7 | h  h  h  h  h  h  h  h  h  h  h  h  h  h  H  H  DH DH DH h  h  h  h  s
 6 | h  h  h  h  h  h  h  h  h  h  h  h  h  h  H  H  DH DH DH h  h  h  h  s
 5 | h  h  h  h  h  h  h  h  h  h  h  h  h  h  H  H  DH DH DH H  h  h  h  s
 4 | h  h  h  h  h  h  h  h  H  h  h  h  h  h  H  H  DH DH DH H  h  h  h  s
---+-------------------------------------------------------------------------
S=stand H=hit D=double P=split

       1) If more than one option is listed,
          options to the left are preferred
          over options to the right.  Options
          less favorable than STAND or HIT are
          not shown.

       2) Use the "Hard Hands" table only
          when the other tables do not apply.

       3) Uppercase options favor the player,
          lowercase options favor the house.


Counting
--------

The best level 1 count with a correlation of 0.96 is:

    A 2 3 4 5 6 7 8  9  X
    0 1 1 1 1 1 0 0 -1 -1

The effects of removal are:

A -0.000238
2  0.000725
3  0.001002
4  0.001443
5  0.001857
6  0.000946
7  0.000505
8 -0.000244
9 -0.000830
X -0.001278


Level One Strategy Chart
------------------------

It is the opinion of this writer that most of the strategy adjustments
do not matter much in double exposure.  The dealer usually has hard 12
through hard 20 or soft 18 through 21, and in these cases, basic strategy
is almost always correct.  In addition, this game is usually played on
a shoe, and as with most shoe games, a large spread is needed (at the very
least 1-10).  Because of this, the results of your minimum bets will have
little impact on your overall result.  Because of this, knowing the negative
strategy numbers will result in very little gain.  After all is said and
done, the following numbers might be of some importance:


                   Double Exposure 21 Strategy Table


     9  10 11 12 13 14 15 16 AA A2 
---+------------------------------
XX |          +2 
---+------------------------------
AX |                   +3 +1
A9 |          +2 
---+------------------------------
15 |+1  
14 |    +2 
13 |       +1 
---+------------------------------
11 |
10 |+3 
---+------------------------------


Wagering Database
-----------------

RULES:  Lady Luck Double Exposure
PENET.: 83% to 1 spot

BETTING =========UNITS TO BET=========== ====HAND==== KLLY ==%BANK==
SPREAD  -1  0 +1 +2 +3 +4 +5 +6 +7 +8 +9 MEAN   VARIA BANK 100R HOUR
------- -- -- -- -- -- -- -- -- -- -- -- ----  ------ ---- ---- ----
 1-20    1  1  4 20 20 20 20 20 20 20 20 .089  125.92 1408 0.63 1.26
 1-20    1  1  2  6 10 13 17 20 20 20 20 .064   54.43  844 0.76 1.52
 1-30    1  1  3  7 11 15 19 23 26 30 30 .087   84.80  972 0.90 1.80
 1-40    1  1  4  8 12 16 20 24 28 32 36 .100  108.40 1079 0.93 1.86





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