Unless you're playing above Unfair, it seems that getting the closest two AIs (left and right of starting position) to chase scouts with their capital ship early in the game seems to completely stymie their expansion. As the AI seems to seldom go for carrier or colony caps (which also tend to come with fighter/bomber squads), they just chase scouts without ever damaging them. And because their capital ship is so busy with that, they basically don't expand anymore. And once you've gotten their poorly defended homeworlds, with three Terran planets it's basically impossible to lose the game.
Of course, this exploits the AI stupidity almost to the max, but it's hard to fault the circling scouts tactics when playing the Vasari as they have no other way to keep an eye on the enemy. The same tactic also works well for capturing neutral extractors early on, although it may requires two scouts: one recharging its AM in peace and doing the capturing, while the other one gives the well militia/pirates the runaround.
