"The Route Pyramid", is a visual representation of an approach to progression that emphasizes building a base of routes that are below the climber's maximum ability. This approach, and how to perfect it, is presented in the popular book The Rock Climbers Training Manual.
Note: Unfortunately, onX has deprecated the data API so this tool is no longer functional. I recommend using thecrag.com instead, as they have built in route pyramids and their user content is creative commons. They even have an import tool if you want to migrate your ticks over.