The Contender is a coming-of-age novel whose protagonist, a black seventeen-year-old high school dropout named Alfred Brooks, lives with his Aunt Pearl and her three daughters in Harlem, a predominantly African American neighborhood in Manhattan, New York City, in the mid-1960s. Alfred's father deserted the family when Alfred was ten years old; his mother died when he was thirteen. On both occasions, his best friend, James, stood by him.
Now, Alfred and James seem headed in opposite directions. One Friday night in June, James breaks into Epsteins' grocery with members of a street gang led by the novel's antagonist, a bully named Major. Alfred is a clerk at the store and inadvertently reveals that there may be money in the cash register on a Friday night; he forgets to tell James about the new alarm system recently installed. Only James is arrested; he is put on probation. Meanwhile, Alfred begins training at Mr. Donatelli's Gym. A wise mentor, Donatelli insists that no one is promised anything, everyone is treated equally, and a man finishes what he begins. The journey, the climb, is more important to Donatelli than the highest goal. Striving is key. Alfred should try to become a contender and let the championships of life come if they will, according to Donatelli.
Alfred begins training at the gym and progresses well. As a spectator, he attends a fight night at Madison Square Garden. When challenged later that evening, he is able to stand up to Major, leader of the street gang. However, Alfred's training is long and sometimes tedious. Alfred cannot yet trust himself; he is too susceptible to the opinions of others. Alfred's employers, the Epsteins, seem to doubt him after the burglary. Eventually, Alfred weakens. He attends a party at the gang's clubroom, indulges in alcohol and marijuana, and passes out. Alfred sees James at the clubroom and discovers that he has become addicted to heroin. Both boys seem lost.
After a hellish Sunday at Coney Island with Major and the gang, Alfred decides to quit boxing. When he visits the gym to clean out his locker, he finds Mr. Donatelli alone. In attempting to apologize to his mentor, Alfred finds that he does not really want to quit. He needs to find out what he could become if he really tries. He reaches a sort of epiphany, a moment of clarity and self-awareness. He wants to become a contender.
Alfred resumes training with renewed enthusiasm. Soon, he is allowed to spar, and in October he has his first amateur fight at a union hall on Long Island. Alfred makes rookie mistakes but wins. Especially impressive that night is an older welterweight named Elston Hubbard. In November, Alfred knocks out his second opponent but is terribly upset because he thinks he has nearly killed the other fighter. His third fight, in December, is a draw, because Alfred is reluctant to throw a punch. Mr. Donatelli advises him that it is time to quit. Alfred lacks the "killer instinct" necessary to go very far, and he could be seriously injured in the ring. Alfred has one more fight scheduled, and he insists on finishing what he has started.
Just before fight time, Alfred, a lightweight, learns that his final opponent is Elston Hubbard, the older, bigger, and stronger ex-Marine who fought so well the night of Alfred's first fight. Donatelli wants to cancel, but Alfred knows he must go on. He barely survives the first two rounds and is dominated by Hubbard. Nevertheless, Alfred finds a few tactics that work, and the third round is a war. Standing toe-to-toe in a brutal exchange, Alfred refuses to fall. He goes the distance. Although he loses a unanimous decision, Alfred knows that he has won the important fight. He has proven to himself that he can persevere and be a contender in life, as well as in the boxing ring.
But Alfred has one more task to accomplish. James is in deep trouble. Apparently stoned, he crashed through the front window of Epsteins' grocery in an awkward attempt at burglary. Alfred finds him at a secret cave where the two hung out as boys. Applying his new attitude and some tough love, Alfred convinces James that there is hope; he helps James to the hospital.
With the encouragement of his college-educated cousin, Jeff, and a schoolteacher called "Spoon," who used to be a fighter, Alfred will finish high school and work with young people in public recreation. He has become a true contender.