A.M. Lightner’s 1967’s The Space Olympics is a standalone juvenile-SF novel.
Herding merinolas1 with his dog Wolf has allowed young Tyros Vann to spend a lot of time throwing things for his dog to retrieve. This hobby makes Tyros of considerable interest to Barnum Winkle, space trader. Winkle has a dream, a dream to which young people like Tyros could be the key.
It all has to do with the brand-new Space Olympics.