Eleven-year-old gymnast Bo Ragatz struggles to cope with a new home, a new school, a bratty younger brother--and a new nemesis. Having finished a year of training, Bo eagerly looks forward to competing in some real meets, but his enthusiasm is tempered by anger at teammate Jim Harmon's hostility. Both are excellent gymnasts, but Jim--constantly pushed to win by his wealthy, arrogant father--feels threatened by this new challenge. When the two boys accidentally switch gym bags, Jim ends up with Bo's homework and ""forgets"" to bring it to the next practice so that Bo can turn it in on time. In revenge, Bo keeps the leather handgrips that Jim depends on for luck. Despite the animosity, though, both are basically decent sorts; come the big meet, Bo returns the grips, though it means a second place Finish for him, and Jim calls off the feud. Jim, an only child, envies Bo his home life, though the Ragatzes are anything but a model family; Bo's rigid, often-absent father is a particularly unattractive character. Still, Matt Christopher fans will enjoy the sports action. For readers unfamiliar with lower-level gymnastics terms and rules, the author appends a glossary and explanatory essay.