Expected Numbers of Specific Cards in Eternal Masters Limited
Eternals Masters has 249 cards: 101 commons, 80 uncommons, 53 rares, and 15 mythics. Each pack also contains a foil card in place of the basic land. This is the exact same distribution as Modern Masters 2015.
While foils don't usually affect Limited much, they are more likely to do so in Eternal Masters because each pack contains one, so I will take them into account. Modern Masters 2015 boxes contain about 16 foil commons, six foil uncommons, and two foil rares (roughly an eighth of which are mythics), so we'll assume a similar ratio for Eternal Masters.
| Contents | Common | Uncommon | Rare | Mythic | |
|---|---|---|---|---|---|
| Booster pack | 8 7/8 commons, 3 uncommons, 7/8 rare, 1/8 mythic | 0.11 | 0.04 | 0.02 | 0.01 |
| Booster box | 24 booster packs | 2.5 | 1.0 | 0.4 | 0.2 |
So you're about 2.6 times as likely to see a copy of any given common as you are to see a copy of any given uncommon, 2.3 times as likely to see a copy of any given uncommon as you are to see a copy of any given rare, and twice as likely to see a copy of any given rare as you are to see a copy of any given mythic.
Now let's apply this information to determine how likely we are to encounter copies of specific cards at each rarity in various Limited environments. We can use this information to determine how viable various draft archetypes are, how strong some cards are in draft, and whether certain situational spells are playable maindeck in sealed.
Draft
An eight-person Eternal Masters draft uses a total of 24 packs and so contains the same distribution of cards at each rarity as a booster box: 2.5 copies of a given common, 1.0 copies of a given uncommon, 0.4 copies of a given rare, and 0.2 copies of a given mythic.
Sealed
Individual sealed uses six packs of Eternal Masters, so each player has access to a quarter as many copies of any given card as in an eight-person draft. A sealed pool will, on average, contain 0.63 copies of a given common, 0.24 copies of a given uncommon, 0.11 copies of a given rare, and 0.05 copies of a given mythic.
Team Sealed
Just in case you happen to find a store running one, three-person team sealed uses twelve packs of Eternal Masters, so each player has access to half as many copies of any given card as in an eight-person draft. A team sealed pool will, on average, contain 1.27 copies of a given common, 0.49 copies of a given uncommon, 0.21 copies of a given rare, and 0.11 copies of a given mythic.
Two-Headed Giant
Two-Headed Giant sealed uses eight packs of Eternal Masters, so each player has access to third as many copies of any given card as in an eight-person draft. A Two-Headed Giant sealed pool will, on average, contain 0.85 copies of a given common, 0.35 copies of a given uncommon, 0.14 copies of a given rare, and 0.07 copies of a given mythic.
