The probability of hitting all 20 is 1 in combin(80,20) = 3,535,316,142,212,180,000. So the odds are more like 3.5 quintillion to one. Assuming 5 billion people on earth, and they all played once a week, there would be one winner every 13.56 million years on average
from The Wizard of Odds Newsletter.
I'm running so bad at the moment I'd probably be better off playing Keno
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