It is important to store cards in a way that prevents them from being stacked on each other
Nightmare Pain X SPELL Continuous During your Main Phase: You can destroy 1 DARK monster in your hand or face-up field, and if you do, add 1 "Yubel", or 1 card that mentions it, from your Deck to your hand, except "Nightmare Pain"
Previous series (barring ZEXAL ) ignored the fact that Monster Cards cannot be Normal Summoned in face-up Defense Position
The finding isnt new, but the time series below covers the full game history and uses median rather than mean, which is more robust to the increasingly long-tail of rules-heavy cards
Buying and Selling Raw Cards One strategy that experienced collectors use is buying raw cards, meaning ungraded cards, that they believe are in condition good enough to grade out at a high level, submitting them for grading, and selling the resulting graded card at a premium
Card advantage matters