Originally posted by Dublimax
You are a big favorite on the flop and turn so you value bet and your opponent hits one of his 2 outs on the river and both opponents bet what they have left. You lose the hand and your EV line follows your winnings graph where you have been unlucky.
All-in EV adds the average amount you'll win in the long run at the point you got it all-in.
Let's say you have AA and your opp has KK. You both had 5$ stacks. On average you'll win 80%. So, from 10$ pot, you'll win 8$ on average. If you win once, you win whole pot, which means you won 2$ more than you'll win on average and this will put your winnings line 2$ over EV. If you lose, your EV line will still gain 8$, but your actual winnings will be -5$.
Now let's assume that your opponent hits a set and you both get it all-in on turn. Assuming that the only way you can win is hitting an A on the river, you'll roughly have 5% possibility to win. Also, let's say that you both had 2$ behind on turn and your opponent bets 2$ all-in into you. The total pot is 10$ and as 5% favorite, you'll get 0,5$ from the pot on average, meaning that if you win, you got 9,5$ more than you will get on average(huge over EV) and if you lose, you'll be only 0,5$ under EV, cause you got 0$ from the pot while on average you get 0,5$.
I hope that someone clarifies if this is 100% correct, but that's how i see it.