How do the topics of sports and games contribute to the theme and create atmosphere in The Great Gatsby? Be specific.

Fitzgerald weaves sports into his novel to help characterize Tom Buchanan and Jordan, as well as to delineate class.

Nick Carraway dislikes Tom and uses sports to deliver one of the more famous digs in the novel. He says that Tom's glory days were in college as a football player and it has been all downhill for him since. He was one of the "most powerful ends that ever played football at New Haven" but had achieved "such an acute limited excellence at twenty-one that everything afterward savors of anti-climax." 

Nick illustrates that Tom is "enormously wealthy" by noting that he brought "a string of polo ponies down from Lake Forest." It's hard for Nick to imagine that somebody of his generation has enough money to do that.

The polo ponies--and riding in general--show how far up Tom is on the "old money" class ladder. Riding and polo playing are the upper crust sports in this novel. This is made clear in the excruciating scene when Tom and his friends, the Sloanes, ride up to Gatsby's mansion in search of a drink of water. When Mrs. Sloane invites Gatsby to dinner, Tom is appalled, especially when Gatsby says yes. To Tom, Gatsby should have known he wasn't wanted. But most tellingly of all, Gatsby does not ride horses: he says he will go get his car and follow them over. The others use this as a way to leave him behind as they ride off. Gatsby's car (though not used for sport; he is not a racer) and his hand gliding represent the future, the new money world of the 1920s that Tom rejects, while the polo and riding represent an elite world closed to Gatsby, despite his money.

Gatsby's pool and the wild games that apparently occur there at his parties help characterize the joyful free-for-all of his jazz-age world, so much more fun than being around Tom, although we learn that Gatsby himself never joins in the pool games.

Finally, Jordan's golf playing helps to characterize her as a new woman of the 1920s and helps highlight her independence and androgyny. Along with her short hair, flat chest and ever cool demeanor, the golf playing helps create a sexually ambiguous atmosphere around her, one that would have stood out more sharply when the book was written. In her golf playing, Jordan steps out of the stereotypically feminine roles of the period. As a golf celebrity of sorts, she is her own person, controlling her own destiny, not simply supporting the career of a man. Golf, especially, is an individual sport, not reliant on teams. Jordan is ever her own person, aloof and independent.