Baseball is the means through which Shirley begins to acclimate to American culture and relate to her classmates. It serves as a common interest that she and her classmates can share and over which they bond, and when Shirley first plays stickball, she feels like part of a community for the first time since coming to America. Even though she isn't good at the game, she appreciates being part of a group. So much so, in fact, that even though Joseph isn't the cutest boy ever, Shirley suddenly perceives him as being really good-looking once he invites her to play b-ball:
His face was pure white, as if his mother had powdered her baby on the wrong end. But to Shirley, at this moment, he was the handsomest boy in all of Brooklyn. (4.11)
It isn't about looks so much as what Joseph offers her here, which is the first friendly gesture she's received since arriving at school. She has felt so lonely and out of the loop that this invitation to play makes her pretty much swoon over the person who makes this offer. Baseball, then, becomes a sort of shorthand for friendship.
Unsurprisingly, then, once Mabel stops throwing punches and befriends Shirley, the first thing she does is bring Shirley into their baseball games and teach her about the sport. Shirley is thrilled:
Mabel's team won. The score was 10 to 2, and though the Chinese rookie never got on base again or caught even one ball, Shirley was confident that the next time… next time, she could. And yes, of course, naturally, stickball was now her favorite game. (5. 105)
Notice the words "next time" in there? They're a pretty big deal. Baseball guarantees Shirley future interactions with the kids in her class. She isn't just in the group for the afternoon, she's in any time they play. This is a pretty big deal for a kid who's come halfway around the world.
Mabel dubs Shirley "Jackie Robinson" because of her pigeon-toed stance and the one time she stole home plate. It's perhaps a more fitting nickname than Mabel realizes, though, and to dig into why this is, be sure to read our thoughts on Jackie Robinson as a symbol elsewhere in this section.
Baseball is a turning point for Shirley in her experience in America, and she appreciates the sport that makes her classmates admire her, latching on to the Brooklyn Dodgers, whom her classmates adore. Because the others love the team, Shirley begins to root unconditionally for the home team and falls in love with the Dodgers—and when she does, she becomes a true Brooklynite, tuning in to the Dodgers whenever she can, and bonding with her friends over the sport.