Originally posted by
fractalspire
This sort of analysis also needs to look at how many rares vs. mythics are in each set.
E.g.,
AKR has a 1:6 upgrade rate, and 29.5% of R-M cards are M.
VOW has a 1:7.4 upgrade rate, but only 23.8% of R-M cards are M.
Y22 has a 1:9.4 upgrade rate, but only only 19.2% of R-M cards are M.
So, it seems to be that they lower the mythic acquisition rate for sets that have fewer mythics to begin with. In each case, the rates are different enough that players are very likely to reach full rares before full mythics, but the rates are actually closer together in the sets with lower upgrade rates, meaning that if a player buys enough packs to complete the rares, they are expected to end up with X% of the mythics for the values of X below: (math correction from /u/KingPiggyXXI
AKR: 56.5% 39.5%
VOW: 56.8% 43.3%
Y22: 55.4% 44.7%
All percentages end up about the same, but with the corrected numbers, Y22 actually has the highest mythic % of the ones I looked at.
On average, collecting a full playset of Rares through duplicate-protected methods like store boosters will yield 50% of that same set's Mythic-Rares, regardless of set. Imagine a sheet of physical cards ready to be cut into packs that has two copies of every Rare and one copy of every Mythic. Thus, collecting two full sheets means collecting a full playset of rares and two of each Mythic-Rare.
A fundamental axiom here is that "A Mythic-Rare card is twice as rare as a Rare card." Or, here is the quote from Mark Rosewater: "Rares appear one per pack, except roughly one in eight packs, when you get a mythic rare instead. The one in eight packs, by the way, might make it feel as if mythic rares are seven times as rare as rares. They're not; they're twice as rare." Source: https://magic.wizards.com/en/articles/archive/making-magic/year-living-changerously-2008-06-02
Example: VOW has 64 Rares and 20 Mythics and a 1:7.4 upgrade ratio. That 1:7.4 ratio is derived directly from the counts of each rarity in the set like this:
2 * 64 + 1 * 20 = 148 (total sheet size) -> 148 / 20 = 7.4
Of course, you and everyone else are opening packs filled from the same sheets, so there is variance. This calculation also currently ignores store packs that yield a wildcard in the rare slot. Finally, the ratios for store packs get very slightly affected by banned cards and full reprints until you have completed your playset of otherwise legal cards.
Example: Y22 (MID/VOW era packs) has 42 Rares and 10 Mythics. To collect a full playset (ignoring inserted wildcards) you would expect to open about this many packs:
2 * 42 + 1 * 10 = 94 (sheet size) -> 2 * 94 (two sheets) = 188 packs
Along your journey of opening 188 packs, you should expect to open about 20 Mythic-Rare cards, which would be half of what you need to complete your playset. Using the ratios:
94 (sheet size) / 10 (Mythics-per-sheet) = 9.4
(ratio of Mythics-per-pack) 1 / 9.4 * 188 (packs opened) = 20 (half a playset of Mythics)
(ratio of Rares-per-pack) 8.4 / 9.4 * 188 (packs opened) = 168 (playset of Rares)
Again, this is lowballing slightly because of packs that yield Rare/Mythic wildcards and ignoring variance. Personally, I believe that the published ratios can be confusing, when the mechanism at play is pretty simple.
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