You&#x27;re misreading. 538 says 97% chance of at least one prize. The EV calculation comes from the Federalist, which doesn&#x27;t give an exact probability for a shared prize, but reduces the payout by 37% to account for it. This is based on another source, which <i>also</i> doesn&#x27;t give a probability that I can see. (That probability might not be super helpful - you want the probabilities of one winner, two winners, three winners, etc. At some point it becomes rounding error, but I wouldn&#x27;t be surprised if you want to go at least to three.)<p>But 538 guesses twice as many tickets sold as the Federalist does.