We compare your guess to the real latest hammer price for that bottle (grouped name) in our auction data.
Points use a logarithmic scale so being wrong by 2× costs more than being wrong by £50 on a cheap bottle.
Bands like “within 12%” are based on how close you were in percentage terms. Practice is random for everyone. Daily cask needs a log-in: same bottle for all players each UTC day, one guess per account per day.