How it works
I myself am a free-to-play-player and already have one deck at max level.
However I still wanted to request cards and I would prefer to max card-stacks to get the extra gold from found cards. Therefore I developed this little tool to help me on my decision.
This tool helps you to determine how much more cards you need to have a troop/building/spell up to level 13.
Enter your Clash Royale PlayerID in the field above to calculate how much cards you are missing to have a full stack.