Simply answer the topic question. For example, I nominate: Batting Alfonso Soriano in the leadoff spot. I know you've got something better.
Rafer Alston consistently attempting his sucky ass floater. You'd think he'd develop that shot or eliminate it from his repertoire. He did seem to be better at it in the playoffs, but that's not saying much.
How is it dumb? He has good speed and can steal bases. Just because he has more power than most lead off hitters, doesn't mean he can't lead off.
Letting Brad Ausmus bad in the 8th inning with the bases loaded and 1 out when you have Craig Biggio, Hunter Pence, Morgan Ensberg, and a slew of other hitters on the bench and your trying to tie or take the lead in a game that your losing. IE. A couple games ago...
Being a Houston sports fan is definitely survival of the fittest or dumbest depending on how you look at it.
If you have an elite power slugger and pay him as such, why would you not put him in a position where he can drive in runs? Batting first means you have the No. 8 hitter and the pitcher as the men in front of you... which often means you're batting without a chance to drive in runs, which given Soriano's power is something he should excel at. Also, the leadoff spot isn't about speed or stealing bases. It's about getting on base and setting the table for the heart of the order, which Soriano isn't particularly good at. Speed is a bonus, not the requirement. Furthermore, it's absolutely silly to sacrifice his run producing potential as a middle of the order hitter with men on base for an extra steal here and there. Why do you think Carlos Beltran always hits 2 or 3, even though he's a tremendous stolen base threat?
Also, with the exception of the Astros teams of last decade and this year's Rockets, it's hard to label any of those as chokes... it's pretty clear in each of those postseasons that the opposition was the better team.