Recently, a friend of mine approached me with a question about what he should read about gambling. He read a lot of specialized forums and looked at information on websites, but he was not satisfied. He started betting on sports not so long ago, but began to lose a lot and realized that he had a significant lack of theoretical knowledge. He loves books and believes that only books present knowledge systematically, and not chaotically, as on many websites. But his question stumped me. Although I have read some books on sports betting, poker and other games, I do not know what specifically to advise a beginner. What books would you recommend?