The Books Balance
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
The chances of all the ways one situation can resolve always sum to exactly 1 — the whole drum, accounted for.
Show
Your 250 raffle tickets give 0.25; everyone else's give 0.75; together, 1.
Watch for
Books that sum past 1 or short of it mean a case was invented or lost — audit before trusting.