This new mulligan rule without Serum Powder or Scry is better than the current rule with Serum Powder + Scry

New rule: 4.7% chance of miss = 95.3% chance of hit
(should also consider the top card of the deck if you're on the draw, with 6 known misses on the bottom of the deck)
Current rule, with Powder + Scry: 94.2% chance to hit during mulligans, 95.0% chance to hit after scry + draw.

So this new rule would be an upgrade without Powder. With Powder the math gets complicated (you could exile multiple Serum Powder at once) but Powder should eliminate ballpark 2/3 of the mulligans to oblivion. In this case, the miss rate would fall to about 1.5%. My suspicion is that because you always Powder for 7 under the new rule it has a little more impact than that and you get the miss rate down to 1%ish

In short: yes please

One source of the mulligan numbers is here: http://www.archive.themanadrain.com/index.php?topic=48196.0

Came here to post this. Seems absurd.

@thecravenone 0.6^6 is 0.046656 or 4.7% with rounding. I'm not sure how you arrived at 5.6 (is this number a percent or just decimal?).

And thank you, I omitted a key word. The 4.7% is the odds of NOT finding a 4-of. I fixed it in original post.

I don't like the grafdigger's idea a lot, but if you stop to think about it, it's kind of a more vulnerable containment priest. I like containment priest to have clocks against decks where it's supposed to be a lock (we're not always gonna have priest + active survival or stuff like that against oath/dredge).

About leyline, a lot of people prefer it and I didn't like it when I tested it for some leagues. But I think it's worth to have it as a possibility, and maybe try it yourself. I had totally forgot about hurkyl's, I think it sounds great against shops, and I think that's what I needed. I'm gonna try a copy of it instead of the null rod. Maybe only 1 stony against PO is madness, but the matchup feel so good and there are so few things I want to cut for the matchup that using that a slot against shops sounds better.