Question of the Day - 21 November 2023

This is the sort of question that, sadly, has been getting asked a lot more often now that reality is being touted as an, er, fluid concept. But wait! I can cut the Gordian knot! How do you determine if ANY research result/report/etc. is genuine? Answer: if several different people/groups, working independently, reach the same conclusion. And thus be it with the house advantage in blackjack, remarkably consistently over the years, within a few hundredths of a percent, even when people were working with the computer equivalent of clay tablets.
The person who asks such a question is the same one who will stand on 15 against a face card, hit a hard 13 against a 6, split 10s, and text while driving. Then he'll tell you "It's all luck anyway."

A problem is that the variance in almost any casino game is high enough that the house edge is never intuitively obvious.  Similarly, the difference between skilled play and just making random decisions is never intuitively obvious in the short run:

$5 blackjack, average game, played for 4hrs
Total moron:  95% CI = -$238 to +$118
Skilled counter:  95% CI = -$265 to +$303
$5 blackjack, average game, played for 1000hrs
Total moron:  95% CI = -$15,364 to -$14,636
Skilled counter:  95% CI = +$4,218 to +$5,382

Yet another reinforcer to the notion that math and science are bullshit, and what you want to believe to be true is more important.

The problem is, almost nobody follows basic strategy. I would get people telling me "You're killin me", to which I would reply "when you stay on 12 against dealer 2, you are losing 7.5%". Stay on 16 against dealer 7, you lose another 4%, and so on and so on. before you know it, you are killing yourself with either "hunches" or just bad knowledge of the game. I remember when Trump casino closed in Atlantic City. The pit bosses were being very outgoing with information, which is unusual. They said the house "hold" was around 14% for black jack. on a game that should be a 1% house edge. That is how horrible most players are. Me, I play basic strategy and employ a progressive betting system. when the table is cool, by bets are cool. I had a streak of 14 visits to Vegas in a row where I came out ahead. I am not a big player (my starting bet is usually $10), but I can say for a fact that info is pretty accurate (I have also sat at a table, lost 12 hands in a row, and left).

I can't tell you how many times I've heard someone say at a blackjack table, "but the casinos wrote that book".

basic misunderstanding of math, people read the books etc. and expect to win big.  They don't understand that probability is still there and you can lose 10 hands in a row.

The house hold only correlates to the house advantage indirectly.  It doesn't account for the number of hands that were played for any given buy-in.  Even if you are at a 1% disadvantage on any given hand if you play hundreds or thousands of hands your expected 1% loss adds up to a larger percentage of your buy-in.

Of the people that doubt the work of mathematicians, or scientists/engineers, yet walk around with a supercomputer/communication/geo-location device (cellphone) in their pockets that is based on ... science and mathematics.

One of my clients was the guy that ran the MIT Blackjack team back in the day. Maybe you don't believe anything about the movie 21, but they used this strategy to clean out the casinos for many years. Anyone can do this if you have patience and practice. It is a marathon, not a sprint....

Statistics are based on big data.

What has not been stated is that if you expect to play basic strategy for the length of two shoes you may or may not come out ahead. If you want to see the numbers work in your favor then you are going to have to put in your time in the pit and have the bank roll to keep you there. Conversely if your up significantly - you have beaten the odds. Guess what - hang around and you can turn that into a statistical 1% loss. If your up take the money and run.

Look at a coin flip. - statistically you should come out 50/50. Do it 10 times and you are just as likely to get 7 heads and 3 tails 42% variance. Do it 1000 times and you might get 570 to 430 1.32% variance. 

The only control you have with the game of blackjack is how much you bet. One common strategy is to increase your bet when you win. Bet $5 (table minimum), if you win bet $10, If you win bet $15, If you win bet $20, $25,$30. Assuming this works out for you you have kept $80. 

Statistically you should not win (nor lose) any more than 6 hands in a row.

So once you have your $30 on the table. Statistics would say go back to the $5 table minimum. As history has shown whenever I do that - I usually pull a black jack and kick my self for not leaving the $30 on the table however that is probably more selective memory than fact. 

Card counters play table minimum until the count changes in their favor and go from $5 to $100 per hand. It doesn't mean they will win those bets just a better chance that they will. Thats also how the house catches them. The wild swing in bets.

The other system people use is called Martingale. Basically when you lose you double your bet. Eventually you will win a hand. This works well when there are high table limits and you have deep pockets. 

5,10,20,40,80,160..... here in Canada table limit on a $5 table is $200.
So after 6 hands (statistically you should not win nor lose 6 hands in a row). If you bet the $160 .... and don't win on that 6th hand there is no 7th hand possible as you have hit the table limit. In this case the casino is using statistics to take away any possible edge the player has. 

So if you are betting $80 (as you have lost your 5,10,20,40 bets - you hit that $80 win ... you have just made $5 as the previous losses add up to $75.

In vegas its quite common to see $10 tables with $1000 limits. Not that there are a lot of $10 tables around anymore. 

10,20,40,80,160,320,640 .... you can get that magic 7th hand in before your capped by at that $1000 limit....slightly better 

Jay, you don't honestly think that Martingale is a long-term winning strategy, do you? 

@jstewa22 No Friggen way is Martingale a winning strategy.
Why anyone would risk $640 to potentially win $10 is simply unfathomable.

I was pointing out that the casinos set table limits based on statistics - aka through table limits they control the number of times that you can double your bet. This ensures that Martingale will not reliably work.

This is an interesting question.  Back in the 1970s there was still some debate about the issue.  John Scarne, author of numerous books on gambling, argued that the strategies of Thorp, Wilson, Braun, and Revere were a fraud and he challenged them to a $100,000 freeze-out match.  (See Scarne's Guide to Casino Gambling, 1978, for details.)  The match never occurred and Scarne died in 1985, his reputation as a gambling expert somewhat tarnished by his stubborn insistence that blackjack could not be beaten.  It is fair to say that today scientific consensus has been reached on this issue.  It has been independently verified by many experts, not just by simulation but by exact calculation of the relevant probabilities.

But that raises the more general question, if there is scientific debate on an issue that you cannot confirm on your own, whom should you believe?  This could apply to dice control, vaccine efficacy, or global warming.  The answer is to await scientific consensus.

"The only control you have with the game of blackjack is how much you bet."

Huh???  You have control over whether you Stand, Hit, Double Down, Split, take Insurance or not...

Interesting comments--but one that hasn't been mentioned are the rules.  Recently more casinos have been padding their bottom lines by changing the rules--a blackjack pays 6 to 5 instead of 3 to 2.  A $25 hit now pays $ 30 instead of $ 37.50.  Amazing--the 6 to 5 tables last week were packed, but the 3 to 2 tables (hidden in the far reaches of the casino) were almost empty!  Well, I guess six is a bigger number than three so the masses are happy!

I’ve always wondered what the house edge is with the dealer acting last. If the player were able to act last my winnings would go WAY up I’m sure.

Yes, the dealer's advantage is acting last. The player's advantage is being able to double down, split, or stand with less than 17.