Even with Vasari starbases, it's easy to bypass through in the otherwise massive solar gravity well.  You can create an effective blockade if you have an ally to double your starbase count up to 8, but even then if there are multiple approaches you might be out of luck.

However, keep in mind that your solar starbase will damage and deplete enemies of antimatter if they try to bypass them.  This will make them easy prey for a mobile defensive fleet that chases after them.  If they greatly outnumber you... well, in that case you probably should be increasing your fleet size rather than building massive starbases that just get ignored...

maybe if the SBs destablization rings are both touching the fleet.  generally, as TEC, i will put 1 SB close the predictable entry points.  like wise i will build SBs at the other stars exit point.  usually the AI cannot cope with bases in both locations.  if for some reason they do pass the bases, entry point mine fields usually finish off the weakened AI fleets along with massive amounts of hangers with bombers.

i will load out my SBs with full armor, weapons, and fighters.  fighters work best against the AI bombers and still do well against long range cruisers.  with other races i will mix it up a bit to take advantage of some of their benefits.  if the AI is really pounding the SBs, I will use flak frigats and repair crusiers holding position near the SB.  i will usually park one or two Caps nearby as well to soak up the experience.

That makes sense, and thanks for the tactics guys, sounds like everything in moderation, Starbase, Small Defense fleet, Mines.