When we first meet Grayson, frankly, he's a little depressing. Yes, he rescued Maniac, but he's an old guy doing a menial job, living at the Y. How'd he end up here, anyway? That's the million-dollar question.
Grayson isn't just any sad old guy you might meet at the bus stop. He is—not was—a baseball player. He may not have had a lot of glory, but he toiled away in minor leagues for more than two decades, "winding up in some hot tamale league in Guanajuato, Mexico, until his curveball could no longer bend around so much as a chili pepper and his fastball was slower than a senorita's answer" (25.30).
Now if that isn't love of the game, we really don't know what is. But why does the fact that he has a history playing baseball matter so much? Because it gives him an identity he can cling to, when he really doesn't have a whole lot else going for him. And—important for Maniac—it gives him something to teach.
We know Maniac is an orphan. But Grayson shows that there's more than one way to be abandoned than through a tragic accident: his parents abandoned him by being drunk and neglectful; his teacher abandoned him by whispering where he could hear, "This bunch will never learn to read a stop sign'" (27.1).
Grayson is on his own because those who should have cared for him failed him. Wait—that sounds familiar. Remember how Uncle Dan and Aunt Dot basically abandon Maniac emotionally? Yeah. This is basically the same thing.
So, Grayson's background is really similar to Maniac's. He took off on his own when he was just 15 and struggled to find his own way through life. This experience lets Grayson provide the right amount of stability for Maniac. When he tries to convince Maniac to go to school, he finally gives up, looking "at him for awhile with a mixture of puzzlement and recognition, as though the fish he had landed might be the same one he had thrown away long before" (23.20).
Translation? Grayson sees himself in Maniac.
We couldn't talk about Grayson without talking about the most shocking part of the book: Grayson's death.
That's right, Grayson and Maniac had about as good a Christmas as anyone could imagine and then, "Five days later the old man was dead" (31.14). It's too cruel for words, right?
Maniac has finally found himself a father. Grayson has finally found himself a son. They've got a nice little cozy home in the baseball equipment room, and no one seems particularly inclined to bother them.
So how in the world could Grayson go and die and leave Maniac all alone. Again? Well, here's the thing. Sure, their little family is cozy and warm. But it's just not right for a kid. Maniac needs a home where he can go to school, where he can be the one learning the lessons rather than teaching them.
Most of all? He needs to learn not to be like Grayson. Maniac needs to find what Grayson never could, and Grayson seems to know that. So, in a way, Grayson sacrifices himself so Maniac can finish his journey and find a real home.