What advice does Mr. Spencer offer to Holden in The Catcher in the Rye?

In Chapter 2, Mr. Spencer tells Holden that "Life is a game that one plays according to the rules." Holden immediately rejects this advice, arguing,

If you get on the side where all the hot-shots are, then it's a game, all right—I'll admit that. But if you get on the other side, where there aren't any hot-shots, then what's a game about it? Nothing. No game.

Throughout the rest of their conversation, Holden's thoughts drift in and out as Mr. Spencer scolds him for not succeeding in school. He asks him, "Do you feel absolutely no concern for your future, boy?" Spencer then tells him he'd "like to put some sense in that head of yours, boy." 

By the end of the novel, it's clear that Holden rejects Spencer's claim that life is a game. When begging Sally Hayes to run away with him into the wilderness, Holden says,

I hate living in New York and all. Taxicabs, and Madison Avenue buses, with the drivers and all always yelling at you to get out at the rear door, and being introduced to phony guys that call the Lunts angels, and going up and down in elevators when you just want to go outside, and guys fitting your pants all the time at Brooks.

Because Holden rejects this "game" completely and attempts to prevent others from playing, he drives himself crazy and ends up in a hospital. By the end, it's not clear whether Holden will ever play the game Mr. Spencer says he needs to play.