SMIP Podcast # 88 - The "London" Mulligan in Vintage

@smmenen said in SMIP Podcast # 88 - The "London" Mulligan in Vintage:

Old School players prefer to play with mana burn, even though that no longer exists in Magic.

SOME do. But anyway, the point you forget is that Old School, Alpha40, whatever, are casual formats. Those are usually rule-bending anyway, since that's the fun of it. So yeah, if you're going out of your way to play a restrictive high-complexity casual time-travelling format, you may as well learn new rules.

Anyway, I won't go too far on this, since I actually don't disagree different mullingan rules could become a thing in the future. I just think it should be a last-last resort.

One thing I don't think people have really touched on with this rule is that it is hard to go away from. This changes so many formats so dramatically that going to a less polarizing mulligan could severely cripple decks.

Here is the additional analysis you asked about in the podcast:

Probabilities of finding a Bazaar under the Vancouver system:

Bazaars\Powders 0 1 4
1 38.58% 41.45% 51.77%
4 86.50% 88.70% 94.18%

For the London system:

Bazaars\Powders 0 1 4
1 58.04% 62.14% 75.52%
4 97.18% 98.08% 99.57%

Methodology: I assumed you

  • keep any hand with at least one Bazaar
  • use Serum Powder whenever you draw it and do not have a Bazaar
  • under the London system, tuck any extra Serum Powders back in your deck before any use of Serum Powder.

Mathematica source code:

last edited by evouga

@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.

Great point! Here are those curves. To keep the plot simple I limited the data to the three most interesting scenarios:

  • the status quo (Vancouver mulligan with no cards restricted)
  • London mulligan with no restrictions
  • London mulligan with Serum Powder restricted
  • London mulligan with Bazaar restricted


The x-axis is cumulative, i.e., the leftmost column is the probability of finding a Bazaar under any circumstance, the second column is the probability of finding a Bazaar and at least one other card in hand, etc.

One interesting result here is that restricting Serum Powder, and instating the London mulligan, would increase the overall chance of Dredge finding a Bazaar, but decrease the probability of Dredge having three or more non-Bazaar cards left over after mulliganing. Of course, since the London mulligan allows the Dredge pilot to sculpt that hand, having fewer expected total cards in hand at the beginning of the game may not impact the deck's performance much.

last edited by evouga

Thanks @evouga !

That helps put some of this in perspective..

@evouga This makes things hard because restricting Bazaar basically kills the deck (you can't play a deck that only gets to execute its plan 75% of the time) but restricting Powder does nothing (lowering from 99 to 98% is basically nothing).

last edited by fsecco

I would make the argument that Restricting powder may actually be pointless because people may stop using it all together. The % gained is so low that many decks may opt to use those slots for cards that give them better matchups elsewhere, like running main deck leylines or unmask or something.

That being said even the % are confusing because Serum powder fundamentally works different under these rules. Being able to see more cards and save the ones you want to keep in your deck before powdering may mean that even though your % gain on the mulligan is minimal your deck quality increase could be substantial.


Restricting powder may actually be pointless because people may stop using it all together

You may well be right about that, although it's important to note that Serum Powder is significantly more powerful under the London system than Vancouver, since you can tuck away cards that are crucial to your game plan (dredgers; Bridge from Below; etc) before exiling your hand. It doesn't sound crazy to me that it might be optimal in a post-London world to aggressively mulligan and Powder not just for a Bazaar, but for a Bazaar as well as some supporting cards.

There is a risk reward analysis that has to go into that that may be beyond my capacity. Like if you mulligan to 6 and your hand is Bazaar, Serum powder, and 5 middling cards, is it better to risk tucking the bazaar back in and then flushing your hand in hopes of drawing a better 5 with a bazaar or just using the natural ability of bazaar to filter your hand of bad cards? My guess is that it is not actually worth the risk and is far more a corner case than somethign that will happen with regularity.

This is excellent, @evouga! This was exactly the type of analysis I was hoping to see. Thank you so much for doing this!

@fsecco and @Protoaddct I think that view is a bit myopic. The 5% failure rate was always more of a talking point than a significant detriment for dredge. So the deck lost 1 in 20 games or 1 game every 7 to 10 matches (or basically once an event on average)? Yeah, the London mulligan eliminates the number of non-games, but that was the stated point of the rules change. The important aspect of the above figure is that restricting Serum Powder would have a non-negligible effect on the starting hand size of the Dredge opener. From my experience with and against Dredge, the hardest games to win post board are the games in which Dredge keeps 7-6 cards, which allows it to navigate the hate, and restricting Powder would lower the likelihood of that by it looks like 10-15% or so (for 7 cards). That honestly might be worth considering if the deck proves too strong if the new rule is implemented.

Edit: A 90% chance of keeping a 6-7 card hand with Powder means I'm not cutting Powders from my dredge list. I think they are well worth the increase from 75% (which includes one Powder from the chart).

last edited by Guest

@chubbyrain said in SMIP Podcast # 88 - The "London" Mulligan in Vintage:

Yeah, the London mulligan eliminates the number of non-games, but that was the stated point of the rules change.

I mean, it was to eliminate non-games, not increase the win percentage of some decks by a large magnitude.

Let's face it here, Dredge foregoes conventional deck building wisdom at its own risk, and it's a calculated risk that you accept when you play a deck with no mana and what is in effect an all in strategy. When WOTC says they are concerned with non-games, they are really referring to decks that play mana lands and spells and some sort of conventional ratio to them. I doubt they are really super concerned about 1 land beltcher and pitch dredge. These are the type of decks that made the no land mulligan rule non viable to begin with.

If you wanted to take a 17 land merfolk deck in legacy and cut it down to 10 lands, chances are you are building a bad deck in defiance of conventional wisdom. This rule is not being passed to accommodate people who want to spit in the eye of the science of these things, but to help the person who built a reasonable mana base to spell ratio from avoiding being crushed by variance too often.


If you would address the entire post rather than one sentence, I would appreciate it. The entire point of my post was that the failure rate of Dredge currently has a very small effect on the deck's actual win rate.


It depends on your plan post sideboard. The gold line is overall higher, but the left tail that determines whether or not you have Bazaar is the most important one. Cutting Powder completely from a list potentially opens up the deck to be that much easier to transform into something that isn't Dredge post sideboard.

@vaughnbros Sure, but the vast majority of Dredge decks in the current metagame aren't running transformational sideboards. Transformational sideboards also have trouble persisting in metagames since they become less effective the more they are known and the larger share of the metagame they hold.


Currently, no, but that's because there isn't much advantage to doing so right now with Hollow One and the mulligan rule as it is. If this change is made, there is more incentive to work on that.

The Dark Depths transformation persisted for years as the best Dredge deck on MODO. I don't think its a question of your opponents response. You are always still a threat to not transform.

@vaughnbros If I remember correctly, it was a number of months. Adaptation included running more Pithing Needles, Wastelands, and leaving Swords in. Still, I would view opening up the Dredge archetype to more variants a positive. The new mulligan would certainly help the Dredge Shops deck with more consistent draws.


I think it opens up the deck quite a bit to new possibilities and opens up other deck to a potential willingness to run main deck hate, which would change the book on dredge completely.

The benefit to opponent's post board is also very noteworthy as it will much easier for them to find a hate piece, and a hate piece with a higher hand size. I'd love to see the graphic Evouga produced, but with 4,5,6,7,8,9 hate pieces from opponents mulliganing to hate (I mean I guess the 4 is kind of there and you can see someone could basically just lock in a leyline if they don't mind top decking the rest of the game).

@vaughnbros said in SMIP Podcast # 88 - The "London" Mulligan in Vintage:

(I mean I guess the 4 is kind of there and you can see someone could basically just lock in a leyline if they don't mind top decking the rest of the game).

Point is if you mull a 1 Leyline hand and they mull to a 1 Bazaar hand, they're winning that game.


Not necessarily. A mull to a 1 Bazaar hand against a 1 Leyline hand is pretty brutal.

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