Single Bet = -EV, Multiple Bets = +EV

[RocketManJames]

So, this might be really obvious, but I thought it was kind of neat. Anyway, here is a case where if you made a single bet you'd be -EV, but if you continued to make the same bet under the same structure, you'd be +EV.

You are a casino and you pay a 40% tax rate on your profit. Ignore everything else (operating costs, profits from non-gambline, etc).

Say you had a game that was 60/40 in your favor.

If you (the casino) were only allowed to play this game once, you'd be -EV.

EV of 1 play of $100: (0.6 * 100) * 0.6 + (0.4 * -100) = -$4
EV of 2 plays of $100: (0.36 * 200) * 0.6 + (0.16 * -200) = +$11.20

From here on out, the EV obviously remains positive. Again, maybe totally uninteresting, but I thought it was a neat observation.

-RMJ