Understanding Offering Rates: How to calculate the chances of getting a new card?

Calculating the chances of getting a specific card isn't as complicated as it might seem. We'll focus on regular packs since rare packs are so uncommon that we can ignore them.

First, when you're in the game at the booster pack screen, there's a small "offering rates" button. Tapping on it will display the offering rates for every card available in that booster.

offering rates
 

The key thing to understand is that the rates vary based on the position of the card you draw: 1st to 3rd card, 4th card, and 5th card. Under each card position, you'll see percentages based on card rarity and for each individual card. The percentage next to the rarity is the total chance for all cards of that rarity.

For example, in the Mewtwo pack booster offering rates, you'll see that for the 1st to 3rd card, there's a 100% chance to get a card with 1 diamond (♦) rarity. Any card of this rarity (like Bulbasaur) has a 2% chance of being obtained. The reason there's a 100% chance to draw any 1 diamond card in this position is that there are 50 cards possible with this rarity in this pack, each with a 2% chance (50 x 2% = 100%).

rates
 

That's the basic idea behind these calculations. If you're using PTCGP Tracker and have saved your collection, we can identify which cards you own and which ones you're missing. To determine the chances of getting a new card in each pack and position, we sum the probabilities for all the cards you're missing. We examine each missing card, identify the pack it belongs to, its position, and its chances of being obtained, then aggregate these numbers for all cards in the same position.

This is how we generate the useful table displayed on your dashboard!

For example:
chances table