Question: Not too long ago, you wrote about how even though all slots are random, casinos come out on top because they manipulate the payouts. For example, casinos pay you $9 if you win, but you lose $10 if they win. In that example, if I bring $100 to the casino, at the end of the night I can expect to have about $90 left, right? But that never happens! If I bring $100 to a casino, every now and then I'll have a winning night, but most of the time I walk out with an empty wallet! It doesn't matter if I play one single slot or twenty different ones, the casino always takes it all. But how is that possible if the house edge is only 10%, like your example?

Welcome to what is known in the world of casinos as 'the grind down'.

The grind down is the combination of tactics that casinos use to get all the money in your pocket, and the longer you stay, the better it works.

The house edge is just a part of it. If you sit down at a slot machine and put in $100, over the course of one wagering cycle you can expect to win back about $90, according to your example. This wouldn't be so bad if one betting cycle lasted two hours, but often it can be over in minutes. And let's be realistic, how many people enter a casino, play for 10 minutes, lose $10, and then leave? Not many.

Instead, people pump that $90 back into the machine, and 10 minutes later they end up with around $81 left. Since you don't like losing, and you just got your first free drink, you put that $81 back in and in a few minutes have $72. And so it goes, till there's nothing left. That's the grind down. When you look at it that way, it's almost a miracle if you do manage to leave the casino with anything at all.

Question: When playing at a blackjack table which pays 6-5 for blackjacks instead of 3-2, is it better to try to maximize my hand and double down when I have a blackjack and the dealer's up card is a 4, 5, or 6?

In a word – no. It may seem that since you are only winning $12 on a $10 bet, it might be better to double and try to make $20 instead. It isn't. That $12 is a guaranteed win, and a guaranteed $12 is always better than a possible $20.

That being said, you should be getting $15 for your blackjack instead of $12. 6-5 blackjack is simply there to take advantage of players who have no idea what they are doing. When blackjack plays 3-2, it is the best game in the casino. But when blackjack pays 6-5, it becomes another throwaway game in the casino, and not worth your time or money.