Tools - Hearthstone HS

Chance of closing a run: how often you win twelve before losing three
Put in your win rate and the run's two targets to get the exact chance of closing it, where the average run really ends, and how violently the odds answer to a few points of skill.

Make the card or open another pack
Put in what the card costs to make, what a pack brings in and the chance it turns up, to see which way is cheaper and how many packs the unlucky half really need.

The same card, going first or going second
Put in the deck, the copies you are waiting for and what the second player is given, to see the gap between the two sides and how many turns of head start it is really worth.