Shuffle exploitation

The shuffle of a single deck is not really shuffled until it is shuffled seven times. If the single deck does not obtain randomness in the shuffle until it is shuffled that many times it would be feasible to track the cards. If a shoes say with six or eight decks is shuffled only twice in reality the tracker may have a great advantage by keying on certain cards. Has anyone done any extensive studies or presently using the key card approach to advantage play. I was wondering if you look for certain conditions before you imploy your strategy against the deck. blackchipjim

I have tended to stay away from shuffle tracking, because most of the people I've read have indicated that their real edge ended up being less than straight counting in most cases.

That’s a common misconception. A single deck must be riffled seven times for it to be reasonably random, but when you include things like washing, stripping and cutting (as most casinos do) you can use fewer riffles and still achieve high degrees of randomness.

Are you talking about keying (sequencing) or shuffle tracking? I’ve done a little of both (although not much…see below).

Absolutely. You will be looking for very specific conditions based on your style of play. For sequencing you have to know that the segment you are keying is not being disturbed too much. Sometimes a slight modification of the house procedure can turn a tough game into a great game. For example, by changing the order of the riffles and strips you can turn an unprofitable game into a sequencer’s dream. It also helps if you can track the sequenced segment, but that requires a fairly weak shuffle in the first place. If you can track the shuffle then you are usually better off tracking it than sequencing it.

Being able to track the shuffle (and cut appropriately) can give you a nice advantage on every shoe you play. Even cutting a few low cards out of play can give you a 1% advantage per shoe. Compare that to the 1% advantage per hour that a straight card counter expects. If you can play 5 shoes per hour then you can expect a 5% win rate per hour. If you can cut some big cards to the front then you can get much bigger advantages than that very often.

-Sonny-

i'm aware of a joint that appears to have a very weak shuffle procedure.
it's eight and six decks. the stripping and cutting is minimal to that of other joints i've watched. also they just break the pack down in equal parts riffle that and then do it again. does this sound like a vulnerable shuffle?

Ok I'm on my girflriends computer and search engines don't work so I can't verify this (btw can anyone help? lol virus maybe?) but my brother is practicing magician and has told me that if you shuffle a deck perfectly (one card after another) that after seven times it is back to the way it originally was. Anyone know if this is correct and does this have any bearing to the original question?

Im a magician aswell! It is true that if you shuffle a deck totally 8 times perfectly, it will be in the order you started with, you can try it yourself .

Keep in mind that a Bridge deck has 52 different cards, but a straight Blackjack deck has only 10 different cards. For the purposes of Ace-sequencing, you can look at a deck as if it has 52 cards. For the purposes of randomizing a deck for Blackjack, far less shuffling is required.

But only if the last card was the first to come out and stay last card.

Alot longer if the 26th card is the first to be dealt thus becoming last card in the newly shuffled deck.

Out of curiosity, I tried it this past weekend. :grin: These were my thoughts going in.

(1) Shuffle tracking on shoes is pretty easy because there's no stripping, just riffling.

(2) It's particularly easy if you're a Hi-Lo counter and can already do decent deck estimation.

(3) It's even easier to shuffle-track at the very beginning and very end of the played shoe, because the first and last riffles in a shoe shuffle get diluted with fewer cards in the middle.

(4) If possible, you want to remember generally what the count was like in the middle of the shoe. It's difficult to know exactly where the middle will be because often the dealer inserts the unplayed cards into the middle of the shoe before shuffling. If they hit the exact middle, you can use the ending count to estimate mid-discard count.

(5) The most profitable slugs to track are the ones where the counts "match" - a high card slug being riffled with another high card slug, or a low card slug being riffled with another low card slug. You can cut the low card megaslug out or cut the high card megaslug to the top.

Results:

I was 1-for-3 in doing it correctly.

The first attempt failed because there were high cards at the beginning and end, but the count ended slightly low and the dealer stuck the low count cards right in the middle, so there was nothing profitable.

Edit for clarity: In the 2nd and 3rd attempts, the dealer put half a deck of unplayed cards well below the midpoint, half a deck just above the midpoint, and half a deck well above the midpoint, which means that the midpoint of the to-be-shuffled stack was 2.5 decks played.

The second attempt was a resounding success - the first 10-12 cards had a count of -5 (i.e. count went up pretty quickly) and the last 12 cards had a whopping +10 count (i.e. count plummeted on last hand). The end count didn't matter because the dealer missed the middle with the unplayed cards. The mid-shoe count was dropping like crazy, so the top slugs matched and I cut them to the top of the deck. I was too much of a wuss to go all-in, so I only bet $15. First hand: TT, T9, T8, AT, dealer: T (showed 3, hit T). Second hand: AT, AT, T9, T4, dealer: 6 (showed T, hit T). Third hand: T6, T2, T5, TT, dealer: T (showed 7). I got the hell out after that. :devil:

The third attempt was a resounding failure - I Wonged in, so I don't know what the count was like at the bottom of the discards, but the last 10 card played had a count of -5 and the middle of the discards were also rising in count (i.e. the middle slug had a negative count) so they matched. I tracked and thought I had successfully cut them into the back of the shoe, but I ended up apparently cutting them to the front. The count went up to +10 or so in the first deck played, giving me a decent reason to stay for the shoe but a complete failure for shuffle tracking.

I wish I had practiced deck estimation better, beyond the half-deck benchmark I usually use for Hi-Lo.

Your post kind of confuses me so I would just like to comment on some of your observations.

(1) Shuffletracking can be easier with certain shuffles, it sounds like you had a good one, but there are many shoe shuffles that strip and riffle.

(2)You're right

(3) Its true that a lot of the time its easier to track slugs at the end or beginning of the played shoe, it also has to do with the fact that in a shuffle such as what you seem to be talking about they will be in the same approximate place most of the time.

(4) In most shuffles the unused cards get broken down into several stacks and inserted in various spots throughout the shoe. Again, if they did otherwise you had a nice shuffle for tracking.

(5) True, but there are few that can actually do this, and no first timers that I've ever known.

In your first attempt you say the count ended kind of high which would mean that there would have been more high cards than low cards in the unplayed cards. If put directly in the middle you may have had a chance to mix 1/2 of the larger ratio of high cards with the high cards from the beginning of the shoe, depending on the shuffle.

In your second attempt you had a dream track with a huge negative count in the first 2 rounds. That would probably be one of the easist and more powerful slugs to track. After you saw those cards come out you didn't have to play anymore, but I would have definetly stayed for the next shoe and cut that monster into play.

I don't understand your 3rd attempt. You say you had a negative 5 in the top 10 cards, but a rising count in the middle, how does that match? It would be more of a neutralizing effect as the count only rises with low cards and a -5 would mean more high cards.

Deck estimation is important, but it doesn't mean a thing if you don't understand what your cutting to, or out. Shuffletracking is not something you can stumble upon and learn right away in the casino. It seems you may have a trackable game here, but I would get some more knowledge of shuffletracking and practice quite a bit first before trying it in a casino. Good luck to you.

I've actually never seen that, even in my pre-counting days. But then again I've never really sought out hand-shuffled games until this past weekend and tended to favor the autoshuffle games for the past 5-6 years because they move faster.

Yes, but most of the time they don't hit the midpoint exactly, so if one is good with deck estimation, one can tell whether the midpoint was the midpoint of the played cards or one of the unplayed chunks. For 75% penetration on a 6-deck shoe that's 1.5 decks of unplayed cards left over. Usually (or at least in the games I saw) the dealer split that into 3 half-deck chunks, putting one about 1/4 of the way up, one halfway, and one 3/4 of the way up. So if the halfway block hits above the midpoint, then the midpoint of the shuffle will be at 2.5 decks played. If the halfway block hits below the midpoint, then the midpoint of the shuffle will be 2 decks played.

Corrected in my post. The count ended kind of LOW because a lot of high cards came out. The unplayed cards should have been rich in low cards.

Man, oh, man ... I didn't even think about that, not even until just now. I was so proud of myself for doing it correctly that I bolted. I should have double-dipped. :sad:

The top 10 cards on the discard pile (the last 10 cards played) had 7 low cards and 2 tens. The rising count in the middle also means that that section was rich in low cards. I was trying to cut that slug out of play.

I usually only gamble once a year, so if I didn't give it a stab, I wouldn't get another chance until probably next summer. It's no coincidence that I limited my excursion to three tries.

the exploit

I guess was using shuffle tracking for awhile without really paying alot of attention to it. I have on occasions noticed the seq. of cards and used them to my advantage. The dealer was amazed and I took alot of heat off myself by doing so. The seris of cards that came out, repeated itself to a greater degree the next shoe dealt. The dilution in the seris of cards that mixed was nearly predictably. I always look for certain dealers who have been with the casino for awhile as they are less apt to be in the spotlight than a new dealer. blackchipjim