Playing defensively?

[Dobian]

I played one game like this and only out of circumstance. I was boxed in early in the game, but had the advantage of having only two ways into my empire, and one of those was next to a black hole. I was allied with the most powerful race, built up a ton of mines and other defenses, and really maxed out my research. I researched all the planet types pretty early, so I had a lot of territory to work with even though I was in only five systems for most of the game. I eventually took several systems from my next-dor neighbor. In my other games, I'm always the hyper-expansionist, and everyone hates me.