Here's a game I just played, where I decided to piledrive estates as the
second pile, after having some... odd shuffles early and losing the City split 7-3, but having picked up KCs and Herbalists.
http://dominion.isotropic.org/gamelog/201212/28/game-20121228-005417-8b29df2f.htmlI do it because
* If I run out any other second pile, I fear him piledriving Estates on me with the +Buy he'd suddenly get from the Cities.
* In spite of losing the City split, and him picking up a matching three KCs eventually, my economy is about as good or better than his.
* There's no cost reduction so it will take a while for either of us to drain Provinces even with fully powered Cities, which gives us some room for tactical maneuvering; and I vaguely suspect my tactics are better than his.
* With decent shuffle luck, I should be able to draw deck anyway, and then the Estates are KC-Bishop fodder; in the worst case, I stall a turn and then I know I'm fine anyway. Him piling Estates in 1 turn is a bigger risk than him grabbing a couple Provinces and then piling Herbalists on consecutive turns. (I didn't think *this* deeply during the game.)
I'm not saying it's the best strategy here, but I felt like a lot could go wrong if I tried to grab Provinces and treasure at this point, or if I made it into a KC race for the second pile.