The Four Horsemen of Aberdeen: Pioneers of Blackjack Strategy

Four Horsemen of Aberdeen

Have you ever wondered who the pioneers of blackjack strategy were? Meet
Roger Baldwin, Wilbert Cantey, Herbert Maisel, and James McDermott. These four
men, better known as the Four Horsemen of Aberdeen, were the first to work out
the necessary calculations to create an almost flawless blackjack strategy.
Their calculations have set the groundwork for almost all blackjack strategy
that’s available today.

Keep reading this article to learn more about the Four Horsemen of Aberdeen
and their journey to creating the first blackjack strategy guide. You’ll quickly
see why they deserved to be inducted into the Blackjack Hall of Fame, which is
one of the most prestigious honors in blackjack.

A Little Background on Each of the Four Horsemen

Roger Baldwin

Math was always Baldwin’s favorite subject in school, so it wasn’t surprising
that’s what he chose to study in college. He ended up receiving a scholarship to
attend Columbia University, where he would eventually earn his master’s degree
in mathematics. Soon after he graduated, he enlisted in the US Army and was
stationed at Aberdeen Proving Grounds.

Wilbert Cantey

Cantey grew up in a Christian home and attended church on a regular basis. He
loved going to events at the church and even dreamed of being a pastor one day.
As soon as he was old enough, he started seminary to begin his pastoral studies.
Unfortunately, he was forced to drop out of seminary because he spent so much
time hustling people at pool and card games. He would later decide to pursue a
master’s degree in mathematics instead. Once he finished his studies, he joined
the US Army and managed to work his way up to a sergeant position. He ended up
being assigned to the Aberdeen Proving Grounds.

Herbert Maisel

From a young age, Maisel was considered to be a mathematical genius. He
always performed well on his math tests and was usually the person other
students would go to for help if they didn’t understand a math assignment. He
decided to join the US Army right out of high school, with his first placement
being the Aberdeen Proving Grounds.

James McDermott

McDermott got excellent grades in high school and was able to earn himself a
full-ride scholarship to Columbia University. After devoting 6 years of his life
to his studies, he managed to graduate with a master’s degree in mathematics.
Despite attending the same school as Baldwin, the two gentlemen didn’t cross
paths until McDermott was stationed at the Aberdeen Proving Grounds while
serving in the US Army.

How Basic Strategy Was First Developed

Fate brought these four men together. The Aberdeen Proving Grounds, where all
four of these men met, was located in Hartford County, Maryland. Soldiers who
served in this unit would assess the effectiveness of new combat weapons, apply
stress tests to tanks and other equipment, and manufacture poisonous gases to be
used in battle.

As you might be able to imagine, the life of a soldier can be very stressful.
Many of the soldiers at this unit enjoyed playing card games during their
downtime to help cope with the stress. One evening, Baldwin decided to join
them. This would be the first time he was introduced to the game of blackjack.
His fellow soldiers explained the rules to him and let him know that the dealer
would be forced to stand on 17 and hit on 16 or lower.

Baldwin was surprised to hear that the dealer had to stick to certain rules,
and it made him wonder if there was a way to calculate the probability of
whether a player would win or lose based on what cards they were dealt. He got a
hold of a piece of paper and a pencil and started to develop formulas to
calculate this out. It wasn’t long before Baldwin became overwhelmed. He still
wanted to do it, but he was going to need some help.

Baldwin approached his sergeant, Wilbert Cantey, and asked if he would be
allowed to use the base’s adding machine to speed up the calculation process.
Cantey agreed to let him use the machine during his free time, and he even
volunteered to help with the calculations. Realizing this project was much more
complicated than he had ever imagined, he also recruited the help of James
McDermott and Herbert Maisel.

Many long nights were involved in the development of this basic strategy for
blackjack. There were times when these four men doubted themselves and wondered
if all their work would be in vain. Despite their doubts, they persevered, and
in just a little over 18 months’ time, their work was complete.

Playing Blackjack to Win: A New Strategy for the Game of 21

They published their work in the Journal of American Statistical Association
in an article named “The Optimum Strategy in Blackjack.” It was 11 pages long
and was read by thousands of people. They went on to write a more thorough
explanation of their discoveries in their book titled Playing Blackjack to Win:
A New Strategy for the Game of 21. The book was first published in 1957, with
only a limited number of copies made. It sold out fairly quickly at the very
generous price of $1.75.

Readers were especially interested in the 10th chapter of their book titled
“Using the Exposed Cards to Improve Your Chances,” as this was the first
blackjack card counting system ever written down and formally published. One of
the only issues people had with this system was the fact that the Four Horsemen
of Aberdeen forgot to take into account that tens and aces are more valuable
than actual low cards, so they should have a bigger impact on the count. Still,
this chapter of their book inspired others to try to create their own blackjack
card counting strategies, and it encouraged blackjack players to try counting
cards to increase their chances of winning.

The Four Horsemen of Aberdeen got together to make a revised version of their
book, which was published in 2008. The authors added a couple new sections to
this book based on what they had learned about blackjack over the years. They
also added commentary from two other experts in the field: Arnold Snyder and
Edward Thorp.

Professionals Test Out Their Calculations

Of course, when any new strategies hit the press, there are going to be
people who want to test them out to check for accuracy. One of the first people
to take an interest in the Four Horsemen of Aberdeen’s calculations was Edward
Thorp. He decided to apply their strategies while spending his Christmas
vacation in Las Vegas with his wife. By the time his trip was over, he had lost
a little over $8. Since he was only there for a limited amount of time, he
considered the results of this test to be inconclusive.

He decided to input their calculations into the computers at MIT, which had
the most advanced software at the time. Almost all of their calculations proved
to be 100% accurate. They had only made a couple errors when it came to their
advice on pair splitting and hard doubling. The errors they made wouldn’t have a
huge impact on a player’s profit margin, however. Edward Thorp would use their
calculations to develop his own blackjack strategies, which he explained in his
best-selling book, Beat the Dealer.

Professional blackjack player Arnold Snyder had this to say about their
calculations: “Their hit/stand strategies, both hard and soft, are 100%
accurate, including the recommendations that hard totals of 12 should be hit
against 2 and 3, and that soft totals of 18 should be hit vs. 9 and 10 only.”
Snyder used many of the strategies addressed in their book to improve his play.

Inducted into the Blackjack Hall of Fame

In 2008, the current members of the Blackjack Hall of Fame included Edward O.
Thorp, Johnny Chang, Tommy Hyland, Stanford Wong, Al Francesco, James Grosjean,
Arnold Snyder, and Max Rubin. The members got together to discuss who deserved
to be the next inductees. Although there were several qualified candidates in
the running, their decision was unanimous. The Four Horsemen of Aberdeen had
made the cut.

At Max Rubin’s 12th Annual Blackjack Ball, the Four Horsemen of Aberdeen were
officially inducted into the Blackjack Hall of Fame. This event is always held
at the clubhouse of a ritzy gated community in Northern Las Vegas. Only those
who are lucky enough to get an invitation are able to attend. Upon giving them
the award, Max Rubin said, “If it wasn’t for them, not one of us would be in
this room.” He recognized the fact that these four men had set the foundation
that made all of their achievements possible.

Baldwin, Cantey, and McDermott felt honored to be able to attend this
luxurious event and meet the other members of the Blackjack Hall of Fame.
Maisel, unfortunately, was unable to make it because he had to stay home to take
care of his wife who had recently had surgery.


The Four Horsemen of Aberdeen all took very different paths in life. Baldwin
chose to work in the applied statistics and data processing field. Cantey ended
up becoming a researcher for the US government. McDermott worked for IBM in
their market research department. Maisel chose to stay in the military, making
it his full-time career. Now retired, they still try to reunite on a yearly
basis to reminisce about the good old days and just to stay up to date with what
is going on in each other’s lives. Their love of blackjack and mathematics will
always draw them close together, and their lasting impact on the blackjack
community will never be forgotten.