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#2: Question closed by user avatar Peter Taylor‭ · 2024-09-20T07:30:01Z (3 months ago)
#1: Initial revision by user avatar Nen‭ · 2024-09-19T19:01:16Z (3 months ago)
Why does group play equalize a lottery's actual Expected Value to the effective Expected Value?
My boss acknowledges that "[the expected value of buying a ticket is negative, or that winning is so unlikely that buying a ticket is a bad investment.](https://math.stackexchange.com/a/1117489)"

But she still wants me to join the lottery office pool. As supporting evidence, she cites

>[My advice to players is to never buy Lotto Max and Lotto 649 tickets on their own. The effective expected value is very low. But for group play, the only games groups should play are Lotto Max and Lotto 649. The larger than average jackpots results in an expected value much larger than average. Given the jackpot is shared, the actual expected value is equal to the effective expected value.](https://forums.redflagdeals.com/starting-sept-10-2024-lotto-max-jackpot-increases-80-million-your-thoughts-2698481/#p39198279)


I link to odds and payouts for [Lotto Max](https://www.olg.ca/en/lottery/play-lotto-max-encore/past-results.html) and [Lotto 649](https://www.olg.ca/en/lottery/play-lotto-649-encore/odds-and-payouts.html). 

I understand just the first 3 sentences. 
I know what expected value (EV) is, but 

#### what's _ACTUAL_ EV??? _EFFECTIVE_ EV???

#### Why does Group Play make the actual EV equal to the effective EV?