This inspiring documentary by Katie Dellarmagiore is a portrait of the Brooklyn, N.Y. junior high school I.S. 318, a formerly troubled school now ranked as one of NYC’s best, in large part because of its championship chess team, which is the best in the country, consistently winning at nationwide tournaments. Chess is a healthy obsession at I.S. 318, and for many of its low-income students, a pathway to success and self-improvement. The film follows the students in their daily lives and as they travel to tournaments. Its chief strength is in its portraits of the student players — many of them the children of immigrants and hard-working single moms — who movingly articulate their hopes, dreams, triumphs, and disappointments. The film also documents I.S. 318’s efforts to fight budget cuts that threaten to eliminate or cut back the chess program and other student activities. Though a bit overlong, the movie, like the 2010 Thunder Soul, demonstrates the incalculable benefits of extracurricular activities in enhancing the lives of students and improving the fortunes of schools. Cedar Lee Theatre.