I got the first Competitive Vintage League Trophy of the July 2-Sept 24th season with Pitch Dredge.
My MVP? 4 Leyline of Sanctity. I beat opponents who had literally 4 Rav Traps in hand tonight, and another player who literally played 4 Tormod's Crypts over the course of one game.
I learned quite a bit, but the main take away I had was that you still want 4 Powder. I tried 0 Powder, 2, and 3, and they were all inferior to 4. The main reason is that Powder allows you to keep larger hands, and thereby do more interaction.
The other thing I learned was that the London Mulligan doesn't really seem to help that much as I expected. In three leagues, I still had to mulligan to 1-3 more than once or twice. What London Mulligan really does, is give you the absolute best hand when you are mulliganing below 4. But it doesn't really help you find Bazaar that much more frequently if you are trying to keep a hand 5 or larger.
Cutting Powder means that you will have to keep hands that are 1-4 cards MUCH more frequently. That's not acceptable for me. Great insights tonight.