@evouga Interesting. The only thing about this analysis is it does not tell me how often I will have 6 cards vs 5 cards, so on and so forth. We all realize that the new rule allows you get bazaar more often, but one of the things it does not tell you is how often you will see it earlier on vs once you have mulled into oblivion. I assume the fall off is a fairly straight forward curve but because of how powder works and how you get to decide what to put back first there may be a higher hand/deck quality issue to think about. If you powder after mulling to 5 for instance you get to save the 2 best cards in the mull which in the past you had no ability to do and there could have been situations where you literally cannot use powder.
Based on this it certainly seems as if Powder is a safe restriction all be it maybe a less than useful one to fix the issue at hand. The first copy only gets you .9% which based on that metric almost makes it feel less than worthwhile to begin with. With such a small % you have to start asking is using something like Street wraith does not provide more value overall to not only find your bazaar but to power your gameplan as powder is a blank card for the deck after the mulligan.
The subsequent powders are also such minimal gains that I'm not sure a restriction would be felt by the community writ large. Once again running a Gitaxian Probe and x Street wraiths could wind up being more viable to the decks functioning.
Truly if this mulligan change makes dredge the dominant deck you basically have 2 options, restrict Bazaar or Restrict 4-5 cards from the deck and see how it works out. I think I like the idea of a restricted list with Bazaar on it as opposed to owe with Troll, Powder, Dread Return, and Bridge on it.