[Comar]

Defending the jump points are definately the way to hold a system. If you need help with the concept ( and possible counters ) read the Weber series on Honor Harrington.

This is a classic choke point defense and mines, satellites, warships and anything else you can drag in can make life miserable for someone jumping in. Even with Dreadnoughts and base ships, mines can wreak havoc. And the more mines, the more havoc.