Cleveland Rocks
Adopting this nickname would play off the fame of the best-known current Cleveland institution, the Rock and Roll Hall of Fame.
The advantages are obvious. Principally they involve the familiarity of the term with the city itself. People around the country associate Cleveland as the home to the Rock and Roll and Roll hall, and beyond that as the supposed birthplace of Rock and Roll itself.
Downsides? There are a couple. First, what exactly is the benefit to the baseball team adopting a name that tacitly makes it a sideshow to another Cleveland institution? Does the team really want to brand itself as a subsidiary institution in its own city?
Beyond that is the question of the degree to which attaching itself to the rock Hall advances the ability of the baseball team to brand itself with potential fans. What is the extent of overlap between fans of baseball and fans of the Rock and Roll? If the brand doesn’t advance the team’s own visibility, what good is it? It would be a hard case to make that fans generally associate rock and roll with baseball.
Overall, then, calling yourself the “Cleveland Rocks” carries with it risks with respect to promoting the one institution you have a real financial interest in promoting.