Blackjack simulation

This repository implements a simulation of the card game Blackjack that can be used with the Bonsai platform.

Run it locally

In order to run the simulation locally you must install the dependencies in requirements.txt and then run

python -m blackjack

Please remember to set in your shell environment the variables SIM_WORKSPACE and SIM_ACCESS_KEY.

Evaluate predefined policies

It is possible to evaluate how well some predefined policies behave with the simulation with the following command

python -m blackjack -p policy_name -e number_of_episodes

Currently the following policies are implemented:

• random: at each step, choose randomly between stay, hit or double-down
• random_conservative: restrict random policy to choose only stay or hit
• player: the program spins up an interactive session where a human player can try their luck by playing blackjack
• basic: use some commonly known strategy to choose the best action for a given game configuration
• brain: evaluate a deployed brain trained with Bonsai

These policies have been evaluated on a total of 100'000 episodes and the mean reward obtained reported in the table below. In addition, we report the mean reward of two brains trained using Bonsai evaluated on ~100'000 episodes. One brain is trained with an inkling defining a custom reward function, and the other defining concepts with goals.

Policy	Mean Reward
Random	-0.565
Random conservative	-0.390
Basic strategy	-0.059
Bonsai brain - reward	-0.057
Bonsai brain - goal	-0.190

Strategy Chart

Once we train a brain with Bonsai, we can generate a strategy chart which shows us the different moves that the brain suggests for a particular game configuration. Rows in the following table represents the value of the player's hand, while columns represent the dealer's hand.

Hard totals

	2	3	4	5	6	7	8	9	10	11
17	S	S	S	S	S	S	S	S	S	S
16	S	S	S	S	S	S	S	S	S	S
15	S	S	S	S	S	S	S	S	S	H
14	S	S	S	S	S	S	S	S	S	H
13	S	S	S	S	S	S	S	H	H	H
12	D	S	S	S	S	S	H	H	H	H
11	D	S	D	D	D	D	D	D	H	H
10	D	D	D	D	D	D	D	H	H	H
9	D	D	D	D	S	D	H	H	H	H
8	S	S	S	S	S	H	H	H	H	H

Soft totals

	2	3	4	5	6	7	8	9	10	11
A, 9	S	S	S	S	S	S	S	S	S	S
A, 8	S	S	S	S	S	S	S	S	S	S
A, 7	S	S	S	S	S	S	S	S	S	S
A, 6	S	S	S	S	D	S	S	H	S	H
A, 5	S	S	S	D	D	D	H	S	H	H
A, 4	S	S	S	D	D	H	S	H	H	H
A, 3	S	S	S	D	D	H	H	H	H	H
A, 2	S	S	D	D	S	H	H	H	H	H