The Four Horsemen of Blackjack
Roger Baldwin, Wilbert Cantey, Herbert Maisel and James McDermott are known as the Four Horsemen of Aberdeen. They published an accurate blackjack basic strategy in 1956 and the book Playing Blackjack to Win in 1957. Their work was foundational, but it does not make one chart correct for every modern ruleset.
The documented contribution
The Blackjack Hall of Fame credits the four mathematicians with the first accurate published basic strategy. Their 1956 article, Optimum Strategy in Blackjack, appeared in the Journal of the American Statistical Association, followed by a book for a wider audience.
They began the analysis while serving at Aberdeen Proving Ground and used desk calculators rather than modern computers. The important achievement was systematic: they evaluated player decisions against a dealer procedure instead of relying on intuition.
Connection to later research
The Hall states that Edward O. Thorp credited their work as an impetus for his research and that they supplied him with data in 1958 before Beat the Dealer appeared in 1962. Credit for later systems should remain separate; influence is not sole authorship.
Recognition
The four were inducted together into the Blackjack Hall of Fame in 2008. The Hall’s book list credits each as a collaborator on Playing Blackjack to Win.
What it means to calculate a better decision
A strategy calculation compares complete outcomes, not just the chance of an immediate bust. For a hit, that includes the possible next cards and the decisions that follow; for a stand, it includes how the dealer finishes. Splits and doubles also change the amount at risk. The same rule assumptions must apply to every alternative being compared.
A deliberately simplified example shows the principle. Suppose action A wins one unit 40% of the time and loses one unit 60% of the time. Its expected return is 0.40 × 1 + 0.60 × (−1) = −0.20 units. Action B wins one unit 35% of the time and loses one unit 65% of the time, giving −0.30 units. Action A is better by 0.10 units even though both are negative.
These invented outcomes are not an actual blackjack hand or the four researchers’ numerical result. They explain why “optimal” can mean a smaller expected loss rather than a winning system. A real blackjack calculation must also handle pushes, blackjack payouts and additional split or double wagers as appropriate.
Basic strategy, composition and counting answer different questions
A basic-strategy chart usually groups hands into hard totals, soft totals and pairs under specified rules. A composition-dependent calculation can also distinguish which individual cards make a total. A counting strategy adds information about cards already removed from a finite shoe and uses a defined method to adjust play or stakes.
Those are related tools, but their results should not be mixed without stating the model. A historical method does not become a universal current chart merely because its authors were pioneers. Read a historical book to understand its reasoning, then use a rule-matched modern reference for the game being studied.
A small edge is an average, not a promise
Even a hypothetical player edge of 0.1% produces only one unit of expected gain per 1,000 initial units wagered on that same basis. It does not promise one winning unit after exactly 1,000 hands. Larger wins and losses can occur around the average, and expenses or execution errors can erase a small theoretical gain. This is arithmetic for understanding an edge, not a claim about a current playable game.
Use free strategy practice to learn the decisions before adding counting. Historical recognition celebrates a contribution to knowledge; it does not certify a reader’s accuracy or bankroll sufficiency.
How to use their legacy
- Match basic strategy to the exact decks and rules.
- Distinguish a rule-matched basic-strategy chart, composition-dependent analysis and card-counting adjustments.
- Keep publication date and assumptions with historical results.
- Do not describe a small theoretical edge as guaranteed session profit.
Sources
Further reading
Their method helped replace folklore with calculation; current use still requires current rules.
