Advanced Red 7 Question

[MrPill]

Mayor, nice message board. Enjoyed reading the Golden Gate a while back and have been lurking here for a while.

I have a Red 7 question to the group, I know from CCC that ZG is a R7 advocate for casual players and may have the answer I'm looking for.

In the Advanced R7 index table that Snyder has on pg. 48 (1998) of Blackbelt in BJ. I'm a little confused on a few of the index numbers he has included for the shoe games. In particular he has RC of 4 as the number to take insurance, to stand on 12 vs 2 and also the point to double down on 10 vs 10.

I realize that these are the numbers he says to follow in the second half of the shoe, but it would seem to me that they would be the same or possibly even lower than the RC number of 2 that he introduces in the beginning of the Red 7 chapter for these same plays.

My logic is that as you get deeper into the shoe, you maintain the same 10/non10 ratio at the same running count, but you have less non10 cards (also less 10 cards). So would this not give you a better chance to catch a 10 (or be under the dealers Ace) due to the smaller number of cards as you get deeper into the shoe and thus a smaller number of occurrences "allowed" in one standard deviation associated with it?

What part of my logic is flawed?

Thanks in advance to all,
Pill

 

[The Mayor]

I don't know anything about Red-7, so I can't comment on your question about the indices, but your last paragraph is interesting.

Suppose you have a hat with 100 red jelly beans and 100 blue jelly beans. Then your chance of picking a red is 50%, the same as if it had 1 of each. But, here is the key, your chances of getting two reds in a row are:

(100/200)*(99/199) = 24.87%

However, if you have a hat with 2 red jelly beans and 2 blue jelly beans, then once again your chance of picking a red is 50%, but now, your chances of getting two reds in a row are:

(2/4)*(1/3) = 16.67%.

Thus, the effect you are referring to says that (for example) with a TC of 10 in a shoe game with 5 decks remaining, you are more likely to get a 20 (a pair of T's) than with a TC of 10 in that same shoe game with 1 or 2 decks remaining.

This effect is true, but many other things effects are true as well, and the situation is very subtle. When you boil it all down, a TC of 10 is much better in a shoe game with 1 or 2 decks left, than if you had that same TC of 10 with 5 decks left. Don Schlesinger refers to this as the "Floating Point Advantage" and he documents it quite nicely in BJA-2nd edition.

In essence, the same TC has a different value in terms of describing your edge, depending on the point in the shoe at which that TC is achieved. You might have a max bet at the top of the shoe when the TC is 5, but by the time you get to the last couple of hands, your max bet should be out when the TC is 4.

--Mayor

 

[zengrifter]

Sorry for the delay MP, I don't have BBIBJ handy, nor do I personally play R7, but I would simply say that one of the drawbacks of the R7 simplicity is the lack of a single coherrent matrix of indices (i#s) - the 1-2D i#s have been 'morphed together for convienience, and the shoe-version assumes 3-4Ds per last half. So ONLY IF the i#s were for a TC -AND- IF the IRC was adjusted per #decks-starting, would the i#s then run consistent regardless of the #decks, but NOT in the case of a pure RC-mode system - UBZ2, SS, KO, R7, and other unbalanced-genre systems have this same quirk. zg

 

[MrPill]

Thanks ZG, I see your point.

Snyder has put the adjustments into the advanced play index table for us R7 players. The RC of 2 takes on a slightly different meaning the deeper you go into the shoe. This is why the index numbers become a little greater than in the first half of the shoe for the same play variations.

Pill

 

[zengrifter]

Honestly, thats my assesment without reviewing the matter or the book, since R7 logic isn't second-nature to me - but thats the drawback to all of the pure-pivot-type systems, different matrices for different #decks. I recall that R7 could be further composited to where using a suitable IRC the 6-8D i#s are simply x2.

R7 is all you need for a few+ outings per year and noses out KO - if a TC-adjust is not difficult for you, the 'TR7' noses out HiLo - add 50 addt'l i#s and you are cooking with fire - count all 7s=.50 and the resultant TC-adjusted 'Half7s' strategy is a solid level-2 hybrid. Other subsets are viable as well, such as increased i#s but RC-based, etc.

The standard R7 will yield the same EV as a full i#s level-2 by playing 75min session instead of 60min -or- by playing 25% faster -or- by playing 12% faster and 13% longer session (69min).