I've made it to arena 5 but still have player cards to gather in arena 3 & 4...I've opened a LOT of boxes using gems on every won box....it seems the rarity of new player cards is way too low. I don't think it should be possible to get to arena 5 and still have cards to gather in arena 3. I'm constantly playing in the lower arenas just to try and get the new cards. I've opened so many boxes my players are lvl 6...but still no new players. Maybe the odds of getting lower arenas cards in higher arena boxes (lvl 3 player in lvl 5 box) should go way up. Maybe make it scale, odds of arena 3 player in arena 4 is 5%, arena 3 player in arena 5 10% etc.