I Can See The Future!
Before I answer, this is how I see this playing itself out: I will answer some stupid answer, then MAYBE another AT member will get in before Enron or Art. One, or the other will then explain fully the prob/stat answer in great detail. Then the other one will chime in to either a) agree with said post, and extrapolate further, or b) disagree, and extrapolate much further to prove their point. Then Rudy will say "roflplzthx".
Of course now that I have foretold the future, will it change?
My answer, and remember I went to El Camino: I think it matters not which door you choose from that point, you are down to a 50/50 at that moment in time. There is probably some shit that deals with the original 66/33 odds that is then blah blah blah based on the reveal of one half of the 66, but its all fuckers to me.
Besides, Dirk was a smart knight and chose the 4th door, that led to the princess and all the riches of the world. (Dragon's Lair Cartoon Reference)
Or, you could go Action Team Stylee, and kick down all the doors, and just fuck up whatever is behind the doors, Elven Chain mail included. No beholder, or chain mail, or Terrasque is a match for The Action Team!