I think it's very unethical for the dealer to make a statement that is [clearly] wrong. At the extreme case of single deck, knowing three non-ten cards makes it 16 out of 49 (97.96%) whereas having 20 with two pictures makes it even more wrong, 14 out of 49 (85%).
It is unethical to give advice that is clearly wrong, but I'm sure the dealer in those situations believes he is correct. An uneducated dealer is one of the worst blackjack players around. They hear every possible superstition and incorrect assumption from their players. Those ideas plant in their heads and they start to notice all the times those assumptions prove true and fail notice when they don't. Your average dealer truly believes insuring a good hand is the right thing to do, that even money is smart, surrender is stupid, and that the guy on third base just took his bust card.
What I find the most unethical is when dealers allow a new/uneducated/drunk player to make an extremely obvious, extremely bad play without a polite confirmation. The Wizard's example of the player hitting a soft 20 is a great example. The dealer should have pointed out the guest had a 20 and then asked if he still wanted to hit. Ditto when players attempt stand on soft 16 and below. On the flip side, nothing is worse than the dealer criticizing a play, even if it's wrong. "You really want to hit that 13 against my 3? You're going to take my bust card and cause the whole table to lose."
I haven't played much blackjack to have any good stories. But last weekend, there was a guy playing that was pretty awful. He got lucky, a lot, and that helped him, but he made some awful plays. He had $200 and got dealt two Kings. Dealer had a Jack showing. He split the Kings, and received an 8 on one and a 9 on the other. Naturally, the dealer had another face card under, and the guy lost $400.
And then there is the every popular BJ dealer advice. I almost always bust with a 5 or 6 and hardly ever with a deuce. That's why the deuce is called " THE DEALER'S ACE "
This does not fall into "worst plays ever seen" but is a follow up to bad dealer advice or wrong advice.
Several weeks ago, a player at my table said something to the effect of the dealer winning 85% of the first hand of a shoe. No sooner had he said that, the dealer was shuffling at the time, the dealer busted paying all 4 of us at the table. Happened the next 3 shoes, I believe, at least he and I won those hands, as both of made a comment about blowing his theory straight to bits.
Last week, as the dealer is having me cut, she says something to the same effect. I says "come on Jane, you dont believe that do you?" She replies with a well I heard it someplace. I ask what the difference is between the 1st hand, 9th hand, and 22nd hand of the shoe? why should the house advantage be better? Got a nonsensical answer about mathematics and such.
Maybe this is the offshoot for a new thread. Dumbest things dealers have said.
Sometimes you're made to feel like the biggest mistake is playing correctly. At Foxwoods a few years ago I was playing two hands of blackjack (8 decks, S17, DAS, Surrender) at a $25 table, the two hands right before the dealer. Some hotshot young guy approached the table and sat down just to my right. I think he bought in for $300 or $400 and played a few hands. Then he had $200 left, and bet $100. The dealer's upcard was a 6; this guy's initial two cards totalled 8. He asked me if he should double down. I advised against it; he proceeded to double down anyway, betting the rest of his buyin. I don't recall what card he got, as it wasn't relevant. I played my first hand, which I also don't remember. My second hand was a soft 18 (again, the dealer was showing a 6): correct strategy is to double, which I did. I got an 8, making 16. The dealer revealed a 10 in the hole, and then a 4 when she hit, making 20.
What happened next was like a Phil Hellmuth outburst: the young hotshot guy immediately gets up from his seat, pointing out that I took the dealer's bust card, and starts shouting to everyone in the vicinity about how I was such an idiot because I doubled down on 18. He continued to verbally express his disbelief at my "stupidity" to anyone willing to listen for the next several minutes.
I learned a valuable lesson that day: don't play at a blackjack table unless the only other person there is the dealer!
Not one of the worst plays I have ever seen, but I saw something the other day that kind of pissed me off. $25 double deck table, player has 9 against a 5. Player asks if he should double, dealer says I wouldn't the way these cards are going. Player hits and gets an Ace and the dealer busts. Player didn't complain but he just lost out on 25 bucks.
I was ridiculed by a new floor supervisor a few weeks ago for splitting my 4's against a 5. I got doubles on both and lost everything when the dealer drew 21 and the supervisor said, see you should never split those 4's, just let the 5 bust.
It wasn't the worst, but a bone head move on my part. I was playing a double deck hand held game about a year ago. My first two cards were low cards and every time I indicated a hit, I continued to get low cards. Finally after asking for about four hits I miscounted my total and thought I had a 22. I threw my cards down to indicated I busted, but the dealer and everyone at the table said almost at the same time I had a 21.