Ten Count - Edward Thorp Card Counting System

Former mathematics professor Edward Oakley Thorp brought card counting to modern Blackjack in 1962, when he published his book, "Beat the Dealer." Thorp's book included what was then considered a revolutionary innovation, the Ten Count system.

Although it has been succeeded by other methods since it was introduced, Thorp's Ten Count System is regarded as the first mathematically proven system for card counting made available to the general public. Thorp wasn't the first to employ card counting for blackjack, nor was he the first to attempt to apply mathematics to the probabilities of blackjack. However, his Ten Count System undeniably blazed the trail for those who followed him in developing other card counting methods.

Some gambling experts consider Thorp's Ten Count not to be strictly a card-counting method. Instead, Thorp's system succeeds in mathematically shifting the winning probability from 6 percent in favor of the house to about 1 percent in favor of the player – a monumental accomplishment in the history of U.S. casino gambling. Most modern card counting techniques are typically some variation of Thorp's method.

Learning how to beat the dealer

Ed Thorp's path to the Ten Count system came by way of MIT, gambling forays in Las Vegas and connections with colorful gamblers.

Thorp earned a master's degree in physics and a doctorate in mathematics from UCLA. He taught mathematics at several top-rank universities including UCLA and MIT. He also has taught courses in "quantitative finance," the basis of his later business ventures.

While a professor at MIT, Thorp met Claude Shannon, with whom he went on to develop what's believed to have been the first wearable gambling computer in 1961-62. Thorp also used the IBM 704, an early mainframe computer, to calculate winning probabilities while developing his mathematical theories on Blackjack.

The professor's theory underlying Beat the Dealer, which led to his invention of the Thorp Ten Count, was based on a 1956 paper written by J. L. Kelly Jr. Kelly wrote a formula to determine the optimal amount in a series of gambling wagers. This formula, subsequently known as the Kelly criterion or Kelly strategy, eventually proved to be one of the most accurate over the long run for predicting probabilities in gambling and in some investments as well. Thorp presented the practical application of the Kelly strategy in a 1961 speech to the American Mathematical Society, and then in his 1962 gambling book Beat the Dealer and his 1967 investment book Beat the Market.

How Edward Thorp's Ten Count System Works

The key to Thorp's Ten Count is the way it determines the ratio of high cards to low cards in the deck by designating a value for each card in a Blackjack game using a single deck. The following table explains the original ratios of Thorp's Ten Count:

Values for Thorp's Ten Count System
A         2          3          4          5          6          7          8          9          10
+4        +4        +4        +4        +4        +4        +4        +4        +4        -9

The mathematics of Thorp's system have consistently proven sound. However, what the Ten Count doesn't do – as with all blackjack card counting methods -- is predict the sequence in which cards are likely to be played. Thorp's method provides a slight advantage for a single deck game, but has little application in the multi-deck blackjack games now common in most casinos.

Deciding to test his theory at casinos in Reno, Lake Tahoe and Las Vegas, Thorp was bankrolled in his experiments by professional gambler Manny Kimmel, a former bookie. Kimmel put up $10,000 – an enormous sum in the early 1960s – so that Thorp could play blackjack in Reno and Lake Tahoe using his method. Thorp's mathematical formula was verified by his winnings, which totaled $11,000 for one weekend of play.

Venturing into Vegas

Thorp then moved on to the big time, playing blackjack at casinos in Las Vegas. His initial efforts in Vegas could have been more lucrative had not his winning ways attracted the attention of casino security. He was expelled from several establishments after he tested his method, won large sums, and became a marked man. In order to continue testing his Ten Count system, Thorp began donning disguises, such as false beards and wraparound eyeglasses.

News of Thorp's accomplishments spread like a lucky streak throughout the gambling world, resulting in his writing Beat the Dealer. The book sold 700,000 copies, becoming a New York Times best-seller and turning Thorp into a celebrity among blackjack players. Beat the Dealer also made history in the world of academic research, since it was one of the few publications in which theoretical research went directly to the public without the typical academic peer review. Beat the Dealer also documented the first time that a computer was used as an aid to gambling.

The publication and sales success of Beat the Dealer terrified casino owners so thoroughly that the Las Vegas Resort Hotel Association changed the standard rules of Blackjack in an effort to thwart card counters who used Thorp's Ten Count system. The new rules forbade players to re-split aces into separate hands, and imposed a new limit restricting the "double-down" bet only to hands totaling 11. Players were so outraged by these rule changes that they left the blackjack tables in droves. Within three weeks, the casinos were forced to revert to the original rules, lest their blackjack profits disappear entirely. However, casinos also switched from one-deck games dealt by hand to blackjack using four decks dealt from a device called a "shoe."

Trumping the Ten Count System

Finally, in 1966, Edward Thorp managed to trump his own Ten Count system with the help of a young computer whiz named Julian Braun. Together they applied Thorp's theory to a new card counting technique called the Hi-Lo Count, unveiled in a revised edition of Beat the Dealer. Today Hi-Lo is considered one of the best single-level methods for beginners to learn blackjack card-counting strategy

Over the years, the former professor has amassed a considerable fortune applying his mathematical theory to both gambling and investments. For many years he wrote columns for The Gambling News that were collected into a book, The Mathematics of Gambling, in 1984. Today he is founder and CEO of Edward O. Thorp Investment Strategies based in Newport Beach, California.

What's more, Thorp's original Ten Count system earned the former professor a secure place in the annuals of gambling. In 2002, Edward O. Thorp was among the first seven inductees into the Blackjack Hall of Fame housed at the Barona Casino in San Diego, California, which has awarded him lifetime free room and meals – provided he never plays in the casino.