I find it interesting that the Ennet House Drug and Alchohol Recovery House (sic) is right next to the Enfield tennis academy, because it got me thinking about some parallels between tennis and drugs (or more specifically, sports obsession and substance addiction).
When the book was going over some of the things that addicts/mental patients learn during recovery, it kept mentioning a bunch of strategies and lessons patients are taught in order to regain control of their lives. These continous lessons of control reminded me of the strict sports lessons of James's Incandenza's father, which were then taught by James to his son, Hal (especially those regarding controlling your body). I'm drawing closer parallels between mental patients and tennis players as the novel goes on, in their similarly obsessive, struggling, carefully monitored existence.
This one line stuck out for me: Drug addicts learn "that, perversely, it is often more fun to want something than to have it" (205). That particular passage paralell's Hal's life: he learned that the better he got at tennis, the more was expected of him. The boys at the Enfield Tennis Academy are all competing to be at the top of the rankings, when in reality, the better they perform, the more is expected of them. Hal captured that idea pretty well in this quote from his digital entertainment cartridge, titled "Tennis and the Feral Prodigy": "Here is how to avoid thinking about any of this by practicing and playing until everything runs on autopilot an talent's unconscious exercise becomes a way to escape yourself, a long waking dream of pure play. The irony is that this makes you very good, and you start to become regarded as having a prodigious talent to live up to" (173). This theme seems to repeat itself throughout the novel... deflated dreams, unreasonable expectations, etc.
I think your connection between sports obsession and substance addiction is spot on. I found this quotation right at the end of the reading:
"he found he liked being with his P.G.O.A.T. straight while she ingested, he found it exciting, a vicariously on-the-edge feeling he associated with giving yourself not to any one game's definition but to yourself . . . the whole substance issue was natural and kind of free" (296).
It's interesting that Orin is so interested in the vicarious thrills here since sports professionals/stars are often living other people's vicarious dreams. I think that the want for freedom is definitely an issue for athletes, who have very little freedom in terms of diet and training. It's like substances are a way out of the strict lifestyle athletes otherwise have to conform to in terms of the maintenence of their bodies.
Another interesting point of convergence is the sense of (forced) community that both the tennis academy and the rehabilitation center share. I found the list from about 200-205 of "exotic new facts" that one acquires from being in rehab. Regardless of their empirical validity, I found this list fascinating and was struck by how similar I imagine the analogous list for ETA would be. It's all about living in close quarters and learning each others' personality quirks, not to mention hopes and dreams and irritating mannerisms and all of that, which can be both extremely frustrating and rewarding all at once. The earlier described incident where the woman stabs the man with a fork sticks out in my mind. We get both parties' accounts, which end up forming a rather hysterical whole. The man who gets stabbed speaks to the difficulties of close-quarter living in the transcript of his drop-in hours session: "Honestly. I know part of this process is learning to lvie in a community. The give and take to let go of personality issues, turn them over. Et cetera. But is it not also supposed to be and here I quote the handbook a safe and nurtuing environment? I have seldom felt less nurtured than I did impaled on that table I have to say" (178). Alas, dorm life feels like this all too often.