I’ve been thinking about writing this post for a while and I haven’t done it before because I know that explaining this to most people in the gambling section will be like talking to a wall.
However, I have finally made up my mind and I hope that this post can improve some people’s gambling behavior and maybe bring a healthy discussion among those who understand it.
The Expected Value (hereafter: EV) of a certain random event is the number that represents better the average value of that event. This is in general. If we apply the concept to gambling, the EV of a bet is the average win or loss of that bet if we take into account all the possible results and their chances.
I think most mistakes gamblers make come from not understanding this concept.
EV applied to poker.Most poker players who have studied poker know the concept. Those who haven’t studied it deeply but have read about poker have a grasp of it.
EV is relevant all through the play (preflop, flop, turn and river) but differences in EV are only relevant before river.
I’ve seen people in this forum complaining about losing versus bad players who always complete their projects in the river (last card) and similar comments. What usually happens to these complaining players is that after seeing that they lose versus players worse than them, they get angry, they start playing emotionally and end up losing all and giving up poker.
What they don’t realize is that even if you are a very good player and you very frequently bet your money when you have a better hand than weak players, you will have streaks when you will lose, because losing hands have also a percentage of winning.
For example: if you go all in preflop with AA vs a shitty hand like 22 and you win, what you are no realizing is that you have been 20% more lucky than you will be on average, so you “owe” 20% of those chips you have won to the expected value.
I’ve taken a sample of my stats to visualize what I am saying:
![](https://ip.bitcointalk.org/?u=http%3A%2F%2Fi66.tinypic.com%2F2yxoepk.jpg&t=665&c=6d1X9lXHUr6eAQ)
That image is showing that I was being luckier than I should, even though I was playing versus players worse than me. So, if the opposite happens, you shouldn’t get emotional, because the green line and the orange one tend to be equal in the long term.
EV applied to Casino Games.Many people think of gambling in casinos as a solution of their financial problems but what they don’t realize is that they cannot have constant profits, the way it is possible in poker:
![](https://ip.bitcointalk.org/?u=http%3A%2F%2Fi63.tinypic.com%2F20gb615.jpg&t=665&c=TcfiOTGa1yxg6g)
I don’t have a program like Holdem Manager for casino games, and I doubt it exists, but I can assure you that if it existed, the orange line, which represents EV, would go constantly down, being the angle (i.e. speed of loss) dependent on house edge and type of game played. The green line, that of the actual money won, would have some spikes up but would tend to match the orange line in the long term.
I am not saying here that nobody should play casino games because I’ve sometimes played them, the same way that I sometimes buy lottery tickets, although I know lottery is also an EV-game. Rather that people playing should learn and know about the mathematical reality behind it.