[HN Gopher] Show HN: Blackjack - Probabilities, Card Counting - ...
___________________________________________________________________
Show HN: Blackjack - Probabilities, Card Counting - Calculation and
Simulation
Author : chkas
Score : 48 points
Date : 2021-08-01 11:37 UTC (11 hours ago)
(HTM) web link (easylang.online)
(TXT) w3m dump (easylang.online)
| mprovost wrote:
| I spent a few summers in the mid-90s card counting with a couple
| friends on summer vacation from college. Vegas was saturated so
| we focussed on Reno and Mississippi. I'm pretty sure we were
| about the only ones in Mississippi because the rules weren't
| always great (the basic rules are fixed of course but casinos can
| and do change the "edge cases" like the ability to double after
| splitting) and they played with big "shoes" of multiple decks,
| usually 8.
|
| The thing is when you count you start at zero when the deck(s)
| are shuffled and then keep a running count. So it's just one
| number. Each card you see modifies the count up or down (we used
| the Omega II system where 10s were -2, aces and 8s were 0, 4/5/6
| were +2, etc). Once you practice (a lot) it's not hard: I could
| count a double deck perfectly as fast as someone could push cards
| off the top.
|
| The thing about playing games with a lot of decks is that they
| let players join at pretty much any point. In a single or double
| deck game you have to wait for the shuffle. So we could wander
| around the casino, wait for a (massive) shuffle and then start
| counting without playing. If the count got good, it could get
| really good, and once a bunch of "bad" cards were out it would
| stay good for a while. Long enough to jump in and play a few
| hands, until the count went bad and then you could pick up your
| winnings and move along.
|
| Fun times. We made good money for college kids but never had
| enough starting cash to really make a splash and get caught.
| ProjectArcturis wrote:
| You discovered "Wonging in". Same strategy as the MIT card
| counting team. Very effective.
| Syzygies wrote:
| Some card counters use two counts, to separate odds from
| strategy. I could never imagine myself memorizing all those
| cutoff numbers. These two counts aren't independent; once you
| establish a 2-dimensional parameter space, the regions of
| interest aren't going to be defined by coordinate cuts. They're
| going to be blobs. But for some of us visual thinkers, blobs are
| easier to remember than a table of cutoff numbers.
|
| I never wrote the code to compute this strategy, back in 1990.
| Today it would be easy. If what I said is obvious to you, have a
| go at it?
|
| A card counting scheme is essentially a gradient vector,
| simplified to varying degrees to be memorable and practical. One
| takes the gradient at a full deck. Should one design the second
| count based on a gradient taken elsewhere, such as the typical
| imbalance when the whale comes over to bet?
|
| Better, the 2-dimensional projection should be allowed to evolve
| in simulation. A pair of gradient vectors is a good initial seed,
| but only that. And a strategy based on "blob" charts will evolve
| differently than a strategy based on cutoff numbers, potentially
| realizing greater gains.
| jedberg wrote:
| > So, in blackjack, you can win if the circumstances are right
| and you have a lot of time.
|
| > If the "true count" is at least 6, we bet $1000, otherwise $10.
|
| If you bet like that in a casino in Nevada, they would kick you
| out so quickly you wouldn't have time to count your chips. In
| Atlantic City they can't kick you out, but they can shuffle the
| deck after every play.
|
| And nowadays almost every blackjack table uses auto shufflers
| that basically makes it like a new deck on every hand, which is
| why I don't play much blackjack these days.
| chkas wrote:
| > And nowadays almost every blackjack table uses auto shufflers
|
| I already thought so. That means card counting was a thing of
| the past.
| jedberg wrote:
| Most casinos still hand shuffle in the high roller pit. So if
| you're betting $50-$100+ per hand you can still get some good
| streaks going, but that's an awfully expensive hobby.
| chkas wrote:
| I wasn't the first to discover this, although I once thought I
| was. About 1990, the Internet was not yet generally available. I
| was interested in Poker and Blackjack. Not in Roulette, it was
| clear that you always lose there. But in Blackjack - it was not
| so easy. I had many discussions with my friends. Then I wrote a
| program in C to work it out. The "expected value" was, as
| expected negative, but with the changing card stacks it regularly
| fell into the positive. I wanted to publish "my sensational
| discovery", but for various reasons I didn't get around to it, 5
| years later, when I tried a new attempt, a short internet search
| showed that others had come to this result long before me ...
|
| Now many years later comes the next attempt to publish it. In the
| meantime I have made the beginner programming language Easylang,
| which is also quite well suited to show mathematical concepts and
| programs on the Internet.
|
| And, I haven't been to the casino in years and have never counted
| cards there.
| Syzygies wrote:
| Great strategy for publicizing a language: Use it to support
| articles people want to read.
| adiM wrote:
| Really interesting programming language. I have been looking
| for a easy language to include simulation examples in my course
| notes, and EasyLang looks almost perfect. Only missing feature
| for me is support for matrix algebra (multiplication, inverse,
| A\b, eigenvalues, etc). I don't know much about web assembly
| and I don't know if there is anything equivalent to blas for
| web assembly which you could interface to.
| chkas wrote:
| Thanks. I'm afraid that won't work with EasyLang. The
| language is kept very simple to make it easier for beginners
| and so that it loads quickly and so that the code can be
| parsed quickly in the IDE. And unfortunately it is not
| possible to include other libraries.
| adiM wrote:
| Thanks for the reply. I may still use it for simple
| examples (as it does fit all other things that I was
| looking for)
| chkas wrote:
| Great. If you need any support, please don't hesitate to
| ask.
| ProjectArcturis wrote:
| About 10 years ago I was in Vegas at the Riviera (now
| demolished). At the time it was on the cheap end of the strip and
| tried to attract customers by offering very attractive odds on
| games. They had a blackjack table that was single-deck, and they
| would deal pretty deep before shuffling. Those are ideal
| conditions for an amateur card counter like myself.
|
| But the real kicker was, they had a side game that paid out extra
| bonuses for blackjacks. Blackjack paid like 5-1 on the side bet,
| suited AK BJ paid like 20-1, etc. I'm forgetting the exact
| payouts.
|
| That night I built a simple spreadsheet to analyze the game, and
| calculate the effect on expected value of removing a card from
| the deck. I discovered that if they dealt 8 cards without an ace,
| the side bet became profitable. If they dealt two hands without
| an ace, it became wildly +EV.
|
| I cleaned up the next morning. Really surprisingly, they never
| cut me off, even though the dealer made some snide remarks about
| card counting and I didn't make much effort to hide my strategy.
| sokoloff wrote:
| I think Vegas in general profits from the awareness of card
| counting and that some bets can be player-advantage at times.
| (They'll back off card counters who are dangerous to their
| profits, but small time counting is overall casino-advantage I
| think [people do it imperfectly, they combine their advantage
| play with other gambling leaks, etc.])
| ProjectArcturis wrote:
| I think in this particular case it was because I was betting
| the side bet hard. Usually the side bets are sucker bets, and
| counters avoid them. They didn't realize that this particular
| side bet could be (very easily!) counted.
|
| But also, the Riviera is out of business, so why assume they
| were good at their jobs?
| User23 wrote:
| I sat next to a guy at the Bellagio who was obviously
| counting with a base bet of a couple black chips, but didn't
| go nuts with his betting when the count was hot. The pit boss
| was an older guy and clearly saw it. In fact he started
| counting out loud and teasing the player. They really don't
| care about some tourist who comes out twice a year counting.
| I assume they do get cross about teams though and maybe local
| grinders too.
|
| Personally I don't see the appeal of counting, except maybe a
| simple Ace-5 count[1] since that requires basically no effort
| whatsoever and nudges the EV to near 1. I like to play to
| socialize and have that VIP experience the good casinos
| deliver so well. When I want to gamble for real money I trade
| options.
|
| Edit: You can even ask for a courtesy shuffle on a cold count
| in a heads up game and I've never seen the pit boss deny it.
| Casual counters just aren't a concern at the strip Casinos.
| It probably doesn't hurt that I toke generously too.
|
| [1] https://wizardofodds.com/games/blackjack/ace-five-count/
| ProjectArcturis wrote:
| Yeah, it took me several years, but I finally came to the
| conclusion that advantage gambling was the hardest way to
| make an easy living. Counting is boring as hell. Casinos
| are boring as hell. Poker can be exciting but not in a good
| way if your living depends on it.
| jedberg wrote:
| What do you do when you're at 16 units and basic strategy
| calls for a split or double down? This is where these
| "simple" ones always get me.
|
| I know that splitting and doubling have +EV which is why
| you do them, but if you're at $maxbet, it can really wipe
| you out if it goes sideways.
___________________________________________________________________
(page generated 2021-08-01 23:02 UTC)