Advantage play in Black Jack boils down to:
1. Placing minimum bets when odds are in the casino's favor. 2. Placing large bets when odds are in the player's favor.
This makes the betting patterns of solo counters very different and easily identifiable from average joes.
Some players do try to add some variance and make intentional non-optimal plays to avoid detection. But every non-optimal play costs money and doing it too frequently eats up any potential profits.
Adding more decks doesn't fully prevent advantage play. More decks aren't harder to count. Adding more decks lowers the variance of the odds distribution through a shoe.
In a one-deck shoe the odds vary in a "spiky" way. It's more likely to be highly favored for the casino or highly favored for the player.
An eight-deck shoe the odds vary in a far smoother way. Most of the time they'll be slightly in favor of the casino or slightly in favor of the player.
A one-deck shoe is better for an advantage player because they can sit out when the odds are unfavorable and make very profitable bets when the odds are highly in their favor. But you can still make money by playing a lot of hands correctly in a eight-deck shoe.
The reason casino's add more decks, is so they can use them up only half the way and then reshuffle again. This way the chance of a big unbalance to build up of which a counter could profit, becomes a lot smaller.
Counters can still make a profit but it's harder. But there are some extra tricks they can use: for instance they can come with a group, set a couple of players at tables and have the others walk around. As soon as some table becomes profitable, the playing member will give some sign and his colleagues will sit down and play at his table.
In blackjack the bet is usually made before any of the cards are dealt, at least in all the locales I've played. Can't judge odds a priori unless card counting.
Is it theoretically possible to beat the casino edge in either scenario?
Yes. It is. And if the casino realizes that you're doing it, you'll be banned from the casino.
So most people who do this come up with clever ways to continue to do so while being less easy to detect, like having multiple people work together. One person stays at the table, betting at a fairly constant rate, while signaling to a partner when the odds are in the players favor so the partner joins the table and places big bets.
The thing is, this all takes a good amount of work and effort, requires a sufficient bankroll to begin with so you don't just have a small run if bad luck and run out of money, and does have some risk of gambler's ruin or just getting detected by the casino and banned.
At some point, it's just a risky investment combined with a job. And you can probably do better by just starting a company or investing your money and getting a job.
> Yes. It is. And if the casino realizes that you're doing it, you'll be banned from the casino.
This is true on Fremont Street, where the pit bosses are fossils and you can probably still get a one way free ride to the desert if you piss off the wrong people. Meanwhile, in Paradise, nobody cares unless it's team play. At least not at the tables the public can get to (so max bet around 20k).
I think you also have to rely on your neighbor?
I played a few hands in Vegas on a lark while attending a conference. I was resoundingly scolded for taking someone else’s cards because I should have stayed rather than hit.