Kirk said of the Starship Enterprise, "There are only twelve like it in the fleet," in Tomorrow is Yesterday. I also get the impression that there are 12 main Sector Starbases. During the series, Enterprise reported to Starbases 2, 4, 6, 9, 10, 11, and 12. Exceptions are Starbase 27 (from TSOP, planned to evacuate colonists to Starbase 27) and Starbase 200 (from TAF, planned to go there after routine planet surveys) which sounded as possible smaller starbases and not Sector Starbases. If the Federation territory was vaguely spherical (possible concept at the beginning of the series), then a 3D sector arrangement could be a 12-sided geometric shape (dodecahedron). Twelve Sectors. Twelve Sector Starbases. Twelve Starships. Too simple? Thoughts?