Don Schlesinger Biography – The Story of Don Schlesinger

Don Schlesinger is a blackjack player with a career that
spans that last 30+ years. He’s probably best known for his book
Blackjack Attack: Playing the Pros’ Way. He was inducted into
the Blackjack Hall of Fame in 2014 for his contributions to the
study of the game.

This page provides an overview of his career as a blackjack
expert and author.

Don Schlesinger Biography

Schlesinger was born in New York City, where he went to City
College of New York and earned a bachelors degree in math. He
later earned masters degrees in French from the City University
of New York.

He started playing blackjack in 1975 in Las Vegas, and he
learned to count cards in 1976 after he read Playing Blackjack
as a Business by Lawrence Revere.

Until 1984, he taught math and French in the New York City
public schools, but he became an executive director at a Wall
Street investment bank.

Could it be that the same set of skills that makes someone an
effective advantage gambler contributes to the success of
executives in the investment banking community?

We’re convinced that it could.

He retired from investment banking in 1998 and now
concentrates his career on the study of getting an advantage at
the game of blackjack. The game had always been a hobby for him;
now it’s probably more of an avocation.

Blackjack Contributions

Schlesinger is best known for studying and publishing
information about the following blackjack topics:

  • Back counting
  • Camouflage
  • Comparing card counting systems
  • Floating advantage
  • Optimal betting
  • Risk analysis
  • Team play

He created the “llustrious 18“, which is a condensed set of
card counting indices. He also created the Desirability Index
and the Standard Comparison of Risk and Expectation (DI and
SCORE, respectively). These are methods of comparing games in
different situations.

He’s also collaborated with a large number of blackjack
experts, including the following:

  • Arnold Snyder
  • John Auston
  • Karel Janecek
  • Katarina Walker
  • Norm Wattenberger
  • Peter Griffin
  • Edward Thorp
  • Stanford Wong

He’s contributed to Blackjack Forum magazine and to Viktor
Nacht’s Advantage Player website, and he’s been mentioned in the
following books:

  • Basic Blackjack by Stanford Wong
  • Beyond Counting by James Grosjean
  • Blackbelt in Blackjack by Arnold Snyder
  • Blackjack Autumn: A True Tale of Life, Death, and
    Splitting Tens
    by Barry Meadow
  • Blackjack Blueprint by Rick Blaine
  • Blackjack Diary by Stuart Perry
  • Blackjack Essays by Mason Malmuth
  • Blackjack for Blood by Bryce Carlson
  • Blackjack: Play Like the Pros by John Bukofsky
  • Blackjack: A Professional Reference, the
    Encyclopedia of Casino Twenty-One
    by Michael Dalton
  • The Blackjack Zone by Eliot Jacobsen
  • Bootlegger’s 200 Proof Blackjack by Mike Turner
  • Burning the Tables in Las Vegas by Ian Andersen
  • The Doctrine of Chances: Probabilistic Aspects of
    by Stewart N. Ethier
  • Dynamic Blackjack by Richard Reid
  • Extra Stuff by Peter Griffin
  • Finding the Edge: Mathematical Analysis of Casino
    by Olaf Vancura, Judy A. Cornelius, and William
    R. Eadington
  • Frugal Video Poker by Jean Scott
  • Fundamentals of “21” by Mason Malmuth, Lynne
  • Gambling 102: The Best Stratgies for All Casino
    by Michael Shackleford
  • Gambling for Winners: Your Hard-Headed, No B.S.
    Guide to Gaming
    by Richard Stooker
  • Gambling Theory and Other Topics by Mason
  • Get the Edge at Blackjack by John May
  • Hollywood Blackjack by Dave Stann
  • Knock-Out Blackjack by Olaf Vancura, Ken Fuchs
  • Legends of Blackjack by Kevin Blackwood and
    Larry Barker
  • Mensa Guide to Casino Gambling: Winning Ways by
    Andrew Brisman
  • Modern Blackjack by Norm Wattenberger
  • Play Blackjack Like the Pros by Kevin Blackwood
  • The Pro’s Guide to Spanish 21 and Australian Pontoon
    by Katarina Walker
  • Professional Blackjack by Stanford Wong
  • Repeat Until Rich by Josh Axelrad
  • Risk and Reward: The Science of Casino Blackjack
    by N. Richard Werthamer
  • Silver Fox Blackjack System by Ralph Stricker
  • The Theory of Gambling and Statistical Logic by
    Richard Arnold Epstein
  • You’ve Got Heat by Barfarkel

Blackjack Attack: Playing the Pros’ Way

Don Schlesinger is best known for his book Blackjack
Attack: Playing the Pros’ Way
, which is in its 3rd edition.
It’s not a cheap book’even a paperback copy costs $30 new, and
good luck finding a used copy for less than $25. Amazon
describes Blackjack Attack as the most important
blackjack book since Ed Thorp’s Beat the Dealer, which
is high praise indeed when you consider that Beat the Dealer is
the origin of all this card counting hub-bub to begin with.

Customers at Amazon have interesting things to say about the
book, too. One customer called Schlesinger the #1 world
authority on blackjack, and he went on in his review to compare
Blackjack Attack with other blackjack books like
The World’s Greatest Blackjack Book
, Beat the Dealer,
Theory of Blackjack, and Burning the Tables in
, and he determined that Blackjack Attack is
the best of the bunch.

Blackjack Attack focuses on answering the
mathematical questions about blackjack that his readers often
ask. These mostly relate to the topics mentioned above—risk
analysis, team play, optimal bet sizing, etc. Answering
questions is how Schlesinger got started writing about
blackjack. According to an interview with Ready Bet Go,
he began by answering letters one by one. This was before the
Internet, so the letters were written on paper and everything.
That led to him writing a regular column, “The Gospel According
to Don”, for Arnold Snyder’s Blackjack Forum. Those
columns were eventually expanded into Blackjack Attack.

According to that same interview, Schlesinger observed that
his book Blackjack Attack just plain contains a lot of
information about the game, the math, and getting an edge that
can’t be found anywhere else.

The Illustrious 18 is the one concept that
Schlesinger is best known for. He first wrote about that in a
September 1986 article for Blackjack Forum titled
“Attacking the Shoe!: A Revealing Study of the Relative Gain
Available from Using Basic Strategy Variations for the Hi-LO
System in a 4-Deck Game”. One of the discoveries he points out
in that article is that index numbers contribute little to
player win rates.

We should pause to point out what “index numbers” mean in the
context of counting cards. Most people are aware now that card
counters gain most of their advantage from raising the size of
their bets when the deck is rich in aces and tens.

But there’s another aspect to counting cards:

Basic strategy changes based on the count.

For example, in some situations where you would normally hit
but might stand if the count was at a certain number. That
number is called an “index number”.

The Illustrious 18” identifies the 18 most
important basic strategy changes you can make according to the
count, in descending order of how much it adds to the player’s
expectation. The insurance index, by itself, accounts for 1/3 of
the entire potential gain to be had from counting cards and
adjusting your strategy accordingly. In fact, the first half of
the chart (the top 9 numbers), accounts for over 83% of your
potential gain.

Some card counters have memorized over 100 different index
numbers. Schlesinger’s discovery made ti clear that you could
memorize far fewer index numbers and give up very little in
terms of expectation versus the casino.

What We’ve Learned about Blackjack from Don

One of the quotes from Schlesinger’s interview at Ready Bet
Go that stood out to us was his reply to a question about how
many other blackjack books he reads. He pointed out that he
reads a lot of them, but he warns that there’s a lot of junk out
there. In our opinion, that’s even truer of the Internet than it
is of the blackjack books that are in print.

He also points out that math skills are useful to a card
counter, but counting cards isn’t calculus. Practice is probably
more important than a large formal math background. It’s just
arithmetic. You have to be able to do it quickly.

We discussed it earlier, but when he explained his “Illustrious
” concept, he clarified that you don’t have to learn
50, 100, or 150 different index numbers. More than 90% of your
edge can be gained just from the top 12 index numbers on his
“Illustrious 18” list. That’s an important distinction to make.
Less time spent memorizing index numbers means more time spent
playing and winning.

SCORE (Standard Comparison of Risk and Expectation)
is a concept that Schlesinger introduced that enables advantage
players to compare different blackjack games in various
situations in order to estimate their advantage play potential
relative to each other.

Floating Advantage is a concept he developed
that estimates how much of an advantage a player has when
carrying a true count deeper into the shoe.

These three concepts are explained in detail in his book
Blackjack Attack:

  1. The Illustrious 18
  2. SCORE (Standard Comparison of Risk and Expectation)
  3. Floating Advantage


Don Schlesinger, like most other members of the Blackjack
Hall of Fame, is a giant in the field. His book Blackjack
Attack, now in its third edition, is one of the most accurate
and information-packed tomes on the subject. The concepts that
he’s responsible for popularizing—The Illustrious 18, SCORE, and
Floating Advantage—are all huge contributions to the field.

What’s next for Schlesinger?

We don’t know, but we do know this—even if he offered no
further contributions to the world of blackjack knowledge, he’s
ensured himself a place in the hall of fame for years, and
probably decades, to come.