Probabilies and EV question

[byronbb]

Forgive my terrible maths.


If I play a 2 game parlay that pays 2-1 for a winner and game A has a probability of 68% and game B has a probability of 65% is the chance of a win (0.65 * 0.68)/2 or 22%? Is the EV = (0.22 * wager * 2) - (wager * 0.78)?

[suicidekings]

The probability of two events in a parlay is just the product of the two.

Bet A: 68%
Bet B: 65%
Parlay: 0.65 * 0.68 = 44.2% chance of winning.

Expected value depends on the price you're paying for the wager. If it was a standard $110 wagered to win $100, then you'd calculate EV as:

EV = (P[win] * amount to win) - (P[loss] * amount wagered)
EV = (44.2% * 100) - (55.8% * 110) = -$17

[shantystar]

i better explained it see my previous post here!

[byronbb]

Thanks man. Here in BC Canada the government run a sports lotto where you have to play at least 2 games where on Over Unders or Point spread $100 pays $200. 3 games $100 pays $400...etc. Anyways today I found some NBA totals that were totally out of wack with the previously stated win expectations but (.442 * 100) - (.558 * 100) = -$11.

I will keep an eye on them and maybe if I get 3 games with + EV the 4 x payout will make it profitable.

[suicidekings]

I actually live in BC as well. Sports Action definitely gouges you on the lines... I'd recommend just putting money into an online sportsbook instead. You'll get a lot more options and enjoyment for your money.

[byronbb]

Yeah I play online. But they had Den at NJ U 207.5 when the Pinny close was 199.5, same with a few others: Dal at NO U 195.5 close is 189 -105.
Then I found a site that actually finds all the +ev lines for you!!!

http://www.prolineplayer.com/odds/Today_BC.php

Looks like you need a win expectation of over 50% for a 2 teamer 25% for 3 12.5% for 4 and 6.7% for 5.

You are right though in general about Sports Action, that is some steeeeep juice people are paying at the 7-11.