Free FullBlackjack Simulator: Any Rules + Any Count System + TC Deviations + C-D Calculator
March 13th, 2026 at 10:16:20 AM
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Hi everyone, we are BJTheorem.
We’ve previously shared earlier versions of the platform here, but we recently implemented a major upgrade to both the simulation engine and the overall system architecture. The platform is now significantly more robust and optimized than before, and has evolved into what we believe is one of the most comprehensive tools currently available for analyzing blackjack strategies.
We’d like to invite you to try the current version (available on web and mobile).
The simulator is fully online and currently free to use (you ONLY need to log in to run simulations or compute the calculator’s best bet.).
You can:
• Configure any rule set (S17 / H17, ENHC, DAS, decks, penetration, table spots, etc.)
• Choose any counting system (Hi-Lo, Mentor, Uston, Exact Composition, or custom tags)
• Use full True Count–dependent optimal deviations for each counting system
• Define your own TC-dependent betting ramp (net amount or percentage)
• Run simulations and obtain full distributions including EV, variance, and Risk of Ruin.
In addition, we provide a full Composition-Dependent Calculator that allows you to:
• Follow C-D decisions in real time (hit, stand, double, split)
• Follow C-D betting decisions in real time (based on EV, standard deviation, and bankroll).
• Obtain optimal theoretical utility at any moment based on the exact composition of the shoe.
The goal of the project is to precisely model real casino environments under any set of assumptions and allow users to evaluate the true performance of a specific strategy, so they can determine the optimal approach given their own objectives and constraints.
If you find inconsistencies, edge cases, or have technical suggestions, we genuinely appreciate the feedback. Many previous improvements came directly from community input.
You can try it at bjtheorem 'dot' com.
Thanks to everyone who tested earlier versions and contributed feedback.
We’ve previously shared earlier versions of the platform here, but we recently implemented a major upgrade to both the simulation engine and the overall system architecture. The platform is now significantly more robust and optimized than before, and has evolved into what we believe is one of the most comprehensive tools currently available for analyzing blackjack strategies.
We’d like to invite you to try the current version (available on web and mobile).
The simulator is fully online and currently free to use (you ONLY need to log in to run simulations or compute the calculator’s best bet.).
You can:
• Configure any rule set (S17 / H17, ENHC, DAS, decks, penetration, table spots, etc.)
• Choose any counting system (Hi-Lo, Mentor, Uston, Exact Composition, or custom tags)
• Use full True Count–dependent optimal deviations for each counting system
• Define your own TC-dependent betting ramp (net amount or percentage)
• Run simulations and obtain full distributions including EV, variance, and Risk of Ruin.
In addition, we provide a full Composition-Dependent Calculator that allows you to:
• Follow C-D decisions in real time (hit, stand, double, split)
• Follow C-D betting decisions in real time (based on EV, standard deviation, and bankroll).
• Obtain optimal theoretical utility at any moment based on the exact composition of the shoe.
The goal of the project is to precisely model real casino environments under any set of assumptions and allow users to evaluate the true performance of a specific strategy, so they can determine the optimal approach given their own objectives and constraints.
If you find inconsistencies, edge cases, or have technical suggestions, we genuinely appreciate the feedback. Many previous improvements came directly from community input.
You can try it at bjtheorem 'dot' com.
Thanks to everyone who tested earlier versions and contributed feedback.
March 13th, 2026 at 11:26:40 AM
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Hello, just briefly checked out your website.
To give some advice, I recommend that you change the ruleset to allow players to split up to 4 times. In the USA where I live, this is the standard. There are also many places in my country that let you re-split aces, which I think should also be an optional rule.
Also running 2000 rounds of a simulation is not enough at all. When I do it on your website, the results are very different every time.
To give some advice, I recommend that you change the ruleset to allow players to split up to 4 times. In the USA where I live, this is the standard. There are also many places in my country that let you re-split aces, which I think should also be an optional rule.
Also running 2000 rounds of a simulation is not enough at all. When I do it on your website, the results are very different every time.
March 13th, 2026 at 11:35:12 AM
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Hello, thanks for your reply.
In our rule configuration, 1 re-split means up to 4 hands total, while 1 split means up to 2 hands. The point about aces is a good one, and we will definitely take that into consideration.
Regarding the number of rounds, it’s not 2,000 rounds in total. The simulations consist of tens of millions of rounds, organized into independent sessions of 2,000 rounds each. This structure helps maintain consistency for strategies where the bet size is bankroll-dependent (percentage betting) and where ruin is possible.
Did you obtain dramatically different profitability metrics? Some variation between runs is expected, but the differences should be relatively small in percentage terms, and the overall scale of the results should remain consistent.
In our rule configuration, 1 re-split means up to 4 hands total, while 1 split means up to 2 hands. The point about aces is a good one, and we will definitely take that into consideration.
Regarding the number of rounds, it’s not 2,000 rounds in total. The simulations consist of tens of millions of rounds, organized into independent sessions of 2,000 rounds each. This structure helps maintain consistency for strategies where the bet size is bankroll-dependent (percentage betting) and where ruin is possible.
Did you obtain dramatically different profitability metrics? Some variation between runs is expected, but the differences should be relatively small in percentage terms, and the overall scale of the results should remain consistent.
