/blackjack-analyst

Blackjack Analyst allows evaluation of blackjack playing strategies through extensive simulation.

Primary LanguageJavaGNU General Public License v2.0GPL-2.0

Blackjack Analyst

Blackjack Analyst allows evaluation of blackjack playing strategies through extensive simulation.

This code was previously hosted at http://www.sourceforge.net/projects/bjanalyst. (Unfortunate URL, I know.)

Writing strategies

To write dealer (or house) strategies, implement the DealerStrategy interface. To write player strategies, implement the PlayerStrategy interface.

Included strategies

Blackjack Analyst comes included with three PlayerStrategy implementations:

  • DefaultPlayerStrategy: Mimics the default dealer strategy by hitting on soft 17 or lower.
  • BasicPlayerStrategy: Uses basic strategy for deciding turn actions, and always makes the minimum bet.
  • TrueCountPlayerStrategy: Uses basic strategy and adjusts his bet according to the hi-lo count.

Only one default dealer strategy is included, called DefaultDealer, which hits on soft 17 or lower.

Simulator options

To get you started, the Simulator class has a main method that will create a table and simulate players all executing a specified strategy. It accepts the following command line arguments:

  • num_rounds: The number of rounds of Blackjack to play.
  • player_names: A comma-separated list specifying the player names.
  • strategy: The player strategy to use. Valid values are default, basic, and true_count which select DefaultPlayerStrategy, BasicPlayerStrategy, and TrueCountPlayerStrategy respectively.
  • verbose: Prints detailed information about every round. Not recommended if simulating many rounds.

Simulator output

When the simulator has completed, W is for player wins, L is for losses, BJ is for blackjacks, P is for pushes, IW is the number of wins on insurance, IL is the number of losses on insurance. (Note that basic strategy never takes insurance.) The number following net reflects the aggregate winnings of the players. The new individual bankrolls of each player follows.

True count strategy

Command line arguments:

--num_rounds=50000 --player_names=Dustin,Ely,Mike,Tim --strategy=true_count

Output:

W=81257, L=98174, BJ=8945, P=17582, IW=236, IL=568, net=37370
Player name=Dustin: bankroll=123520, table=Table1
Player name=Ely: bankroll=106710, table=Table1
Player name=Mike: bankroll=105100, table=Table1
Player name=Tim: bankroll=102040, table=Table1

Basic strategy

Command line arguments:

--num_rounds=50000 --player_names=Dustin,Ely,Mike,Tim --strategy=basic

Output:

W=80133, L=99162, BJ=9035, P=17581, IW=0, IL=0, net=-37590
Player name=Dustin: bankroll=85170, table=Table1
Player name=Ely: bankroll=88040, table=Table1
Player name=Mike: bankroll=91710, table=Table1
Player name=Tim: bankroll=97490, table=Table1

Default strategy

Command line arguments:

--num_rounds=50000 --player_names=Dustin,Ely,Mike,Tim --strategy=default

Output:

W=73447, L=98467, BJ=8945, P=19141, IW=0, IL=0, net=-232050
Player name=Dustin: bankroll=41470, table=Table1
Player name=Ely: bankroll=41640, table=Table1
Player name=Mike: bankroll=41140, table=Table1
Player name=Tim: bankroll=43700, table=Table1

Verbose output

Command line arguments, specifying only one round:

--num_rounds=1 --player_names=Dustin,Ely,Mike,Tim --strategy=basic --verbose

Output:

Dustin joins the table
Ely joins the table
Mike joins the table
Tim joins the table

New round started with 4 players
Dustin bets 20
Ely bets 20
Mike bets 20
Tim bets 20
Dustin is dealt THREE of DIAMONDS, QUEEN of SPADES (13)
Ely is dealt SEVEN of HEARTS, QUEEN of DIAMONDS (17)
Mike is dealt ACE of CLUBS, TWO of CLUBS (13)
Tim is dealt THREE of DIAMONDS, ACE of CLUBS (14)
The dealer shows the up card SIX of DIAMONDS
Dustin stands with hand THREE of DIAMONDS, QUEEN of SPADES (13)
Ely stands with hand SEVEN of HEARTS, QUEEN of DIAMONDS (17)
Mike doubles down, now has hand ACE of CLUBS, TWO of CLUBS, JACK of HEARTS (13)
Tim doubles down, now has hand THREE of DIAMONDS, ACE of CLUBS, SEVEN of DIAMONDS (21)
The dealer reveals its down card, has hand SIX of DIAMONDS, SIX of CLUBS (12)
The dealer hits, now has hand SIX of DIAMONDS, SIX of CLUBS, SEVEN of CLUBS (19)
The dealer stands with hand SIX of DIAMONDS, SIX of CLUBS, SEVEN of CLUBS (19)
Dustin lost to dealer with 13, lost 20
Ely lost to dealer with 17, lost 20
Mike lost to dealer with 13, lost 40
Tim beat dealer with 21, won 40

W=1, L=3, BJ=0, P=0, IW=0, IL=0, net=-40
Player name=Dustin: bankroll=99980, table=Table1
Player name=Ely: bankroll=99980, table=Table1
Player name=Mike: bankroll=99960, table=Table1
Player name=Tim: bankroll=100040, table=Table1