Adding 50% to EV

[assume_R]

This is probably a very obvious question, but why do you have to add 50% to the EV to get the house edge?

For example, if your expected win is -50.4%, that is considered a house edge of .4% correct?

But -50.4% = (End_Money - Initial_Money) / (Money_Wagered)

Or am I calculating EV wrong?

Thanks!

 

[Sonny]

For example, if your expected win is -50.4%, that is considered a house edge of .4% correct?

It depends on what you mean by "expected win of -50.4%." Normally the term "expected win" means EV, so if you bet $1 and expect to lose $0.504 then the house edge is -50.4%. But if you have a 50.4% probability of losing an even money bet then the house edge is 49.6% - 50.4% = -0.8%.

-Sonny-

 

[psyduck]

But if you have a 50.4% probability of losing an even money bet then the house edge is 49.6% - 50.4% = -0.8%.

-Sonny-

Shouldn't the house edge be 0.8% and the player's edge be -0.8%?

 

[assume_R]

Thanks Sunny. Psyduck you're right I think. When sites report EV such as the b.s. engine and wizard of odds is it iba or tba?

 

[Sonny]

Shouldn't the house edge be 0.8% and the player's edge be -0.8%?

Yes, my mistake. The house edge would be 0.8%.

-Sonny-

 

[Sucker]

But -50.4% = (End_Money - Initial_Money) / (Money_Wagered)

Or am I calculating EV wrong?

Thanks!

The formula for EV is: (wins - losses) / (wins + losses).