Hi, all
Does anyone understand WHY the 'floating advantage' identified by Don S. occurs? The fact that it occurs seems well-established in BJA Chapter 6 but the REASON it occurs eludes me.
Best to all!
SiMi
Not sure this is correct but this is my reasoning
Think of the off the top house edge in a single or double deck game vs a six or 8 deck game. The house edge is smaller.
So at a RC of 0, on average your edge will be greater with 1 deck left to play, than right off the top of a shoe
See BJA3, bottom of page 70 and page 71. Too often, people jump right into the charts and tables of the book without reading the explanatory text that precedes them. I never present material without first explaining how it was generated and how to use it.Originally Posted by SiMi
Don
Hi, CC and Don
Thanks for your replies! I get that the FA tells us that your edge is smaller when the deck/shoe is 'fatter' than when it is thin. I re-read ch. 6 twice and asked a friend to read it before I posted. I may not be asking my question very well. I'm not questioning that the phenomenon is real.
I can see, as BJA says on p.70-71 that, as the deck is depleted, the edge increases for all counts -4 to +4. This is another way of restating the phenomenon you call the 'Floating Advantage.'
As I wrote before, I do not question that the phenomenon is real (because I've seen it a lot), I'm asking WHY does it occur? Why is a TC of +4 worth more at the end of a given shoe than at the beginning? I understand that the shoe is more depleted but that is just restating the phenomenon.
I thought the whole point of adjusting the RC to the TC based on deck depletion was to make it so that our counts are "true" and apply whether we have 5 decks to go or only 1/2 deck to go in a 6 deck shoe. That way, we can use a bet ramp based on TC regardless of where we are in the shoe. (In fact, because I've seen FA so much, I use a more aggressive spread when I get lucky and get a really deep cut.) Again, the whole point of doing the TC conversion is to get an "apples to apples" comparison for any deck penetration, right?
The fact that FA exists implies that TC conversion is NOT enough. There must be something else going on that makes a TC of +3 a little better at the end of a shoe than it was at the beginning, right? What is causing this change and is there something we can do about it? Is it that we do not count 7,8 and 9 cards in HiLo? If so, how does that cause the effect? Is there something going on with the cards behind the cut card that causes this effect? Is it something to do with the overall loss of information due to the way HiLo works (lumping Hi cards together, lumping Lo cards together and, again, ignoring neutral cards)? If that's it, why doesn't that get sorted out in the MC simulations of BILLIONS of rounds?
I must be missing something because I thought I understood what I was doing but FA strikes me as something that doesn't fit with my understanding of what I'm doing.
Again, thanks for trying to help and sorry for being so dense!!
Happy Thanksgiving to everyone!
SiMi
Read my first post. That helps explain why it happens. Smaller number of decks = lower off the top house edge.
Depleting the shoe while remaining in moderately neutral counts, on average, is similar to decreasing the number of decks being used, lowering the house advantage. Of course theres no real practical difference unless you find very deep pen.
One reason can be understood by making an analogy to marbles in a bag. A TC is represented by the ratio of black marbles to white marbles. If you have a 6 to 4 ratio of marbles with 240 marbles in one bag and 30 marbles in another bag the odds are the same for drawing one marble so they seem equivalent. But in BJ your round isn't about 1 card. It is about hand matchups followed by you drawing cards and the dealer drawing cards (flipping over his hole-card is drawing a card from the unseen cards. So you get a strong matchup like 11v5. The dealer must draw a card when he flips his hole-card and daw at least one other card to complete his hand. You will draw one card to your double. You hope to get a T. Early in the show the odds of what is drawn next doesn't change much regardless of what you draw. Late in the shoe if you draw a low card the dealer is far more likely to draw high cards when 1 of a dozen or so low cards is removed than early in the shoe when one of a hundred low cards are removed. So it is the fact that the resolution of hands after the initial deal are often dependent on the play of more than one card. When that is true the removal of the first card has a much larger affect on the probability of cards that follow. Various ways this effect plays out as multiple cards are dealt in the process of play for both the initial deal and the play after the first 2 cards are dealt to everyone.
With that difference at different levels of pen noted and the effect being absolute, nobody has proven that is the cause of floating advantage. I think Don said he explained it is his "Eureka!" paragraph at the bottom of page 70. He may be right but I am not sure the basic strategists advantage must be constant on average throughout the shoe is a given. If I am right that he feels this is the explanation, then the reason is that the advantage above TC +4 and below TC -4 falls at deep pen so the advantage in-between must increase. If you accept that BS advantage must be constant on average at different penetration levels throughout the shoe this must be true. I am not sure that you can jump to that conclusion.
Last edited by Three; 11-18-2018 at 09:01 PM.
Hi, Don and CC
It's not only possible I read the pages and still think they don't explain the phenom, it's a fact! I read the two pages several times and asked a friend to read them as well. We then discussed the issue for about an hour before I posted and, again, after you guys replied. I am reading as carefully as I'm able but that doesn't mean I'm understanding what I'm reading, of course.
I think Three's explanation is the best version of what I'm looking for. Again, I may not be stating my problem very well but his response attempts to use probability and discrete counting examples to show WHY the same TC might have different edges in different scenarios, although I'm not fully understanding his reply at this point. I apparently have a real dead spot in my thinking on this issue and I will need to read BJA and Three's reply many more times to understand why a given TC does not represent the same edge at any level of penetration.
Nevertheless, thanks to all of you who replied and I hope everyone has a great Holiday!!
Best,
SiMi
Yes ,it is.
TC10 at the upper half shoe, and TC at the bottom half shoe, the ratios of 7,8,9 are not the same, on average.
We never take insurance at the first round for a 4 decks game, even the TC tells you it is enough.
Ratios of 7,8,9 not the same, or those with 0 count... can be found some figures in Thoery of Blackjack.
With less cards remaining you will receive on average more BJs per 100 hands. Assuming an identical composition of the cards remaining.
An extreme example to illustrate the point.
Assume from an 8 deck shoe you get down to the final 10 cards, 5 of which are aces and 5 of which are face cards. Your chance of receiving a BJ is roughly 55.55%
Now assume from the same 8 deck shoe 60 cards remain with the same deck composition. 30 aces and 30 face cards. Your chance of receiving a BJ is roughly 50.85%
Btw it's the exact same reason why in single deck u get slightly more BJs than in shoe games. Theres nothing magical about it, it's just mathematics.
To get a blackjack your first card must be either an ace or a 10 value card. Whichever one it is it slightly increases your chance of getting the 2nd card you need as there is now 1 less card remaining in the pack but still the same number of cards u need for the BJ.
That effect is simply amplified when there are fewer cards remaining. Or to put it another way the effect is extremely weak when there are many cards remaining.
Thanks angle!
Are you saying that the ENTIRE FA effect is due to more Blackjacks or is it that combined with the way HiLo treats 7,8 and 9 as peterlee seems to say?
Seriously, thanks again to everyone for helping!
Best,
SiMi
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