This guy was next on the list for a game I was playing. While he was waiting he was betting with someone at then table that a jack 5 or 2 would hit the flop. They bet twice and one of those cards hit and the guy quit. He then sat down next to me. I started betting with him thinking it has to be in my favor but either the jack 5 or 2 hit nearly 90% of the time in the next 20ish flops. I even started only betting when I would have one of those cards in my hand but they would still hit. One time I had j5, 2 people at the table had 2 of the cards and the guy I was betting with had 22! Lol and the flop came jjx.

So what are the odds of one of those 3 cards (jack,5,2) coming on the flop?

Thanks

This question has been asked a few times here before, but not for a while. I get the sense that this is a standard "scam" anymore. Here is how it works:

Scammer: "Man, Js, 5s, and 2s have been flopping all night! I bet the next flop has a J, 5, or 2 in it."

Victim: (internal thoughts- that is only 3 cards. Surely that is pretty rare and I am getting even money on a bet, I'll take that all day!) "Hey I'll bet yet."


The probability can be computed by figuring out the probability that none of the three cards hits the flop. There are 12 cards out of 52 unseen cards (assuming we don't know what we are going to be dealt) so that is 40/52 * 39/51 * 38/50 =~ .447. So there is just under a 45% chance of those cards not coming. Which means there is a 1 - .447 =~ .553 chance that at least one of those cards flops.

So if you pick three cards out ahead of time and deal three cards off the top of the deck, there is just over a 55% chance of you getting at least one of them.

In practice however, your situation is more dire (assuming you are the victim). Because every hand does not go to the flop. Hands that reach the flop often contain Aces and Kings and rarely 2s and 5s. Because people are more likely to hold big cards, small cards end up on the flop slightly more often than you would find if you just dealt three cards out of a full deck. Spadebidder.com has done extensive analysis on these flop effects. So the scammer has an ever high chance of winning if he uses low cards in his set of three.

Ya good point. Thanks. It was getting pretty sick though when 2 others would bet with me because they had some of the cardsin their hand also and it would still hit.

Umm, you don't offer the bet to people who have already seen some of the dealt cards. Normally you make the bet before dealing, or to bystanders not in the hand if the deal has been done (which increases your advantage since you don't bet on cards in your hand).

I think he was saying he made the bet before the hand, but after the fact found out that certain people had held certain cards.