[khorboth]

Another possibility is that calculating jumps is just really hard. like mind-bogglingly computer-intensive. Think like a building-sized bank of computers working for years to plot a single new jump course intensity.

So, interstellar pilots rely on what are basically maps. They stick to well-charted routes. They don't strictly *have* to, but if you don't, you're effectively stranded in the middle of deep space. The odds of randomly jumping back in are literally astronomical. Everybody's working from the same set of maps, so everybody is going on the same routes. Therefore, choke points.

An army could gain substantial advantage by using a new route, but once the data is captured, it's done. And once the route is used, it's at least known that *somebody* has it.