Pop reports tell you what is actually rare
A population report is the grading company's running census: for every card, how many copies PSA has graded and how many earned each grade. It is the closest thing this hobby has to a rarity ledger, and it settles arguments that price guides can't.
The catch is access. PSA's own report now requires a Collectors account login, and even signed in, it works like a phone book. You look up one card, read its row, and start over. There is no way to ask the question collectors actually have: show me everything, sorted by what's hardest to find in a 10.
BetterPop is that missing sort button. If you're new to reading populations, start with what a pop report is, or jump to where the thresholds sit in our guide to low pop Pokemon cards. Card by card deep dives live on the blog.