4 ideas
Fast Eddie Felson arrives at a Chicago pool hall to challenge Minnesota Fats at straight pool and plays him for more than a day and a half, building a large lead. Eddie then loses everything, a case of superior skill defeated by a steadier opponent over endurance, self-control, and the discipline to quit while ahead.
Bert's diagnosis is that Eddie did not lose because Fats was better but because part of him wanted to lose and built excuses in advance, such as drinking or bragging. A competitor who keeps a ready-made alibi is protecting his ego against the risk of losing at full effort, and that protection makes the loss likely. On this view, character means committing completely to winning, not having more ability.
Bert Gordon offers to stake Eddie's games in exchange for most of the winnings, presenting his money and knowledge as what separates Eddie from success. The stake works as a claim on the player: the backer benefits from convincing the talent that he cannot win alone, and so from keeping him dependent and emotionally isolated. The backer's real product is the player's belief that he needs a manager.
A hustler's trade requires seeing each person as either a mark to deceive or a resource to use. The novel shows that when a way of competing is also a way of seeing, it takes over the relationships that could have saved him.