How does Dredge sideboard in the mirror match?
I'm not going to post decklists, because it's all theoretical. But lets assume both builds play Dread Return and then lets talk about ubiquitious main deck cards:
Basically, I have around 8 cards in my sideboard I would bring in for the matchup, but don't know what cards I would board out.
Does Serum Powder stay in or would do these get boarded out? My Leylines of the Void are in sideboard, and think substituting Leylines 1 for 1 with Powder is a reasonable way to sideboard the matchup.
Cabal Therapy doesn't really get any cards from the opponents hand, but you it does create sacrifice outlets if you have bridge from below online. Basically, it quickens the deck and is an engine.
Dread Return still seems like the best path to victory, if you can remove an opposing leyline of the void. But you could remove Dread retun and all the targets for it, streamlining the deck a little better.
Ichorid still seems very usefull to exile opposing Bridge from Belows.
Are there different sideboarding theories for being on the play vs the draw? Put otherwise, would you have a different sideboard in game 3 than game 2?