Yea a bi weekly tends to only be about 12 weeks and some cap you at 10 cuts and of course you can add them late season so the numbers aren't always true.
But my bi weekly's tend to always be small lawns. Doing half an acre or more bi weekly doesn't sound to good to me thus the prices reflect smaller lawn prices. Some tiny 25 dollar cuts mixed in with mostly 30-35s. My best bi weekly is 2 properties a rental that's 35 and a machine shop that's 65 so its 100 every 2 weeks. Most of my bi weekly's are on my partners list and reflect that the lawns are smaller and houses denser on that side of town.
But we try to split them up as evenly as possible so ideally 15 being done each week. In reality someone always asks for a favor or something causes us to skip them on the on week and by the end of the year it seems to always be 10 one week 20 the other. And thus we talk in terms of heavy week and light weeks. But never all on one week that would be unworkable.