How many races do you play against in SP?

[rdouglass]

I have found that playing without neutrals (in a large galaxy) gives me a much more challenging game. I found that when there are neutrals, I cannot resist taking them and exploiting them as slaves. That usually gives me another (different) colonizing tech and atmosphere capabilities. It doesn't seem like the AI uses this tactic and it gives me a huge advantage.

If I start the game w/ medium number of AI and no neutrals in a large galaxy, I find (like most others doing this) that the AI can be quite strong once you finally contact them at around turn 60-75. It definitely puts more emphasis on researching your own techs (or intel'ing and stealing which is my fav).