"The Mathematics of Gambling" is quite different from those other books. For instance, it does not focus on just one game like most of the others. In fact, it barely explains a game at all. Instead, it describes the mathematical methods that might be used to win at the game more consistently. Think of this book as a starting point to understanding gambling theories.
This book gives a quick overview of making money, or losing money more slowly, at various games of chance. Thorpe was best known for "inventing" a system of card counting for blackjack and basic strategy. He wrote the 1962 book "Beat the Dealer" which spawned a whole genre of win-at-gambling books that continue to this day.
The book starts with Blackjack, of course, and gives a very brief overview the game and betting strategies. This is mathematically heavy and many details are left out. It is followed by a counter-point of Baccarat which Thorpe concludes mathematically has much less room for winning strategies.
At this point, the book is just getting started. Although most gambling books focus on card games, or just casino games; Thorpe also gives mathematical insight into Horse betting and Backgammon. There are no clear-cut strategies forced upon the reader, just a general pointing in a direction that might prove helpful.
And that is the whole issue with this book. If you are looking for the one-true-path to gambling winnings, look elsewhere. If you want, instead, to read about mathematics applied to betting games this is the book to start reading. The writing is precise and clear and the math is not too horrid. Especially helpful is the time Thorpe spends setting up the underlaying math to working out a potentially successful strategy. Also, the final section on money management is excellent even if your game of chance is the stock market. A game Thorpe also wrote about in "Beat the Market".