RESETTING GAME STATISTICS & ANALYTICS
These are rather DANGEROUS settings. You have to be careful and make sure you select the right reset because you will wipe out all of your game data for this particular game including all card sets, but not other games.
Access it by opening the app and then navigating from the Home Screen:
HOME → SETTINGS → SCROLL DOWN TO GLOBAL SETTINGS → RESET THIS GAME'S STATISTICS
You can restore all of your game data from the cloud server, but any new games you play forward and back up to the cloud again, will be lost forever.
Only Game Center statistics for Global Leaderboards and Achievements are not affected and will remain there forever as they are part of a global scoring system.