Card Rarity Ratios between Expert and Goblins Versus Gnomes Packs

I just asked about the difference in totals of collectible cards between Expert packs and Goblins Versus Gnomes packs: Card Counts for Expert and Goblins Versus Gnomes Packs

So clearly Expert Packs are drawing from a larger pool. But I'd like to ask a couple follow up questions:

1. What is the ratio of legendary/epic/rare/common of the collectible Expert set compared to the collectible Goblins Versus Gnomes set.

2. When opening a pack are the chances to draw a specific rarity adjusted to accommodate the difference in ratio.

In other words, do I have a better chance of getting a legendary when opening an Expert pack, a Goblins Versus Gnomes pack, or are my chances the exact same?

Solution 1:

Blizzard has stated that the probability of opening a card of a specific rarity is the same in Classic and GvG boosters. That said the probability of opening a specific card in a GvG booster is higher than the chance of opening a specific card of the same rarity in a Classic booster, because there are less cards of each rarity in GvG than in Classic.

Propablities for each rarity can be found here.

Solution 2:

For part 1 of the question, the stats for the Expert Set, the Goblins Versus Gnomes Set, and the Grand Tournament Set can be found here: http://hearthstone.gamepedia.com/Rarity

The Expert Set has a total of 433 collectible cards:

• Legendary: 33 or about 8%
• Epic: 74 or about 17%
• Rare: 162 or about 37%
• Common: 164 or about 38%

The Goblins Versus Gnomes Set has a total of 218 collectible cards:

• Legendary: 20 or about 9%
• Epic: 52 or about 24%
• Rare: 74 or about 34%
• Common: 72 or about 33%

The Grand Tournament Set has a total of 232 collectible cards:

• Legendary: 20 or about 9%
• Epic: 54 or about 23%
• Rare: 72 or about 31%
• Common: 86 or about 37%

For part 2 of the question Ral Zarek's link is a great source: http://us.battle.net/hearthstone/en/forum/topic/15551555731#4

Things that can be derived from this data:

1. The chances of opening a card of a given rarity are identical across all sets
2. The chances of opening a card identical to another card in the pack are proportionate to the number of cards of that rarity in the set
3. Because the concentration of Legendaries and Epics have gone up in Goblins Versus Gnomes and the Grand Tournament Sets, a higher number of packs relative to the set card count will need to be opened to obtain all the cards in the set