bfbagain: To SSR:Answers, answers.

[bfbagain]

[Brick]

Can you at least explain what you dont understand or why I'm wrong?

[Parker]

> Can you at least explain what you dont
> understand or why I'm wrong?

Okay, let's start by summarizing what is not in despute:

The single deck game is the better game to play.

Someone spreading $5-$100 on a six deck shoe with mediocre rules and bad pen will likely experience bigger swings (and hence, more volatility) than someone spreading $5-$20 on a good single deck game.

Everybody agrees on the above (I think).

However, our goal is not to reduce volatility at all costs. If it were, we simply would not play at all, or perhaps flat-bet the table minimum. Our goal is to win money while keeping risk of ruin to an acceptable level.

Besides, the question that started all this was simply, "which has more volatility -- single deck, double deck, or shoes?"

So, we look at SCORE (in the classic sense), assuming a $10K bankroll and optimal betting. A single deck game (H17, DA2, no DAS, 35/52, 1-4 spread) has a SCORE of 98.60, with a standard deviation of $995/hundred hands. The 6D game (H17, DA2, DAS, 2 decks co, 1-12 spread) has a SCORE of $7.18, and SD of $268/100 hands. Clearly, the single deck game is more volatile.

Why the apparent contradiction? The kicker is that our unit is $5 on the shoe, and $42 on the single deck game.

Sure, we could bet $5-$20 on the single deck game, but assuming that we had a $10K BR and were okay with full kelly ROR, why on earth would we want to? The goal, after all, is to make money. Note that our earnings will be nearly $100/hundred hands on the single deck game, and a pitiful $7.18/100 hands on the shoe -- with the same risk of ruin.

I think we got hung up on practical vs. theory. Terms like volatility and variance have specific mathematic definitions, and mathematically speaking, single deck games have more volatility than shoes.

The reason that the shoe looks higher in the examples cited in other posts is becsause our average bet is much higher.

Perhaps the most important conclusion a beginner should draw from all of this is that volatility and EV usually go hand in hand.

Note: I pulled the numbers up very quickly using BJRM, so they may differ slightly from those presented in other posts (and that's why I suddenly shifted from 1-20 to 1-12).

[pm]

> Okay, let's start by summarizing what is
> not in despute:

> The single deck game is the better game to
> play.

> Someone spreading $5-$100 on a six deck shoe
> with mediocre rules and bad pen will likely
> experience bigger swings (and hence, more
> volatility) than someone spreading $5-$20 on
> a good single deck game.

> Everybody agrees on the above (I think).

> However, our goal is not to reduce
> volatility at all costs. If it were, we
> simply would not play at all, or perhaps
> flat-bet the table minimum. Our goal is to
> win money while keeping risk of ruin to an
> acceptable level.

> Besides, the question that started all this
> was simply, "which has more volatility
> -- single deck, double deck, or shoes?"

> So, we look at SCORE (in the classic sense),
> assuming a $10K bankroll and optimal
> betting. A single deck game (H17, DA2, no
> DAS, 35/52, 1-4 spread) has a SCORE of
> 98.60, with a standard deviation of
> $995/hundred hands. The 6D game (H17, DA2,
> DAS, 2 decks co, 1-12 spread) has a SCORE of
> $7.18, and SD of $268/100 hands. Clearly,
> the single deck game is more volatile.

> Why the apparent contradiction? The kicker
> is that our unit is $5 on the shoe, and $42
> on the single deck game.

> Sure, we could bet $5-$20 on the single deck
> game, but assuming that we had a $10K BR and
> were okay with full kelly ROR, why on earth
> would we want to? The goal, after all, is to
> make money. Note that our earnings will be
> nearly $100/hundred hands on the single deck
> game, and a pitiful $7.18/100 hands on the
> shoe -- with the same risk of ruin.

> I think we got hung up on practical vs.
> theory. Terms like volatility and variance
> have specific mathematic definitions, and
> mathematically speaking, single deck games
> have more volatility than shoes.

> The reason that the shoe looks higher in the
> examples cited in other posts is becsause
> our average bet is much higher.

> Perhaps the most important conclusion a
> beginner should draw from all of this is
> that volatility and EV usually go hand in
> hand.

> Note: I pulled the numbers up very quickly
> using BJRM, so they may differ slightly from
> those presented in other posts (and that's
> why I suddenly shifted from 1-20 to 1-12).

..and it shows pretty clearly why SSR, while correct in his claims, was bringing to light points that were essentially useless.

Thank god for the brilliant blackjack experts on these boards that take the time to help out us beginners, and on a free message board at that. You guys are absolutely amazing.

[Brick]

Not sure sure what you mean by "One more time," I'm not SSR. The only reply I got was from BJfan implying I'm some kind of a ground hog. Maybe he got offended when I crawled into his underground operations of secured territory.

I appreciate your time to reply ,but it really was not neccesary to explain to me about SCORE,basic concepts, why single deck is better and so forth. I'm not a ploppy or newbie when it comes to blackjack. I certainly agree with you,however let's comment about my reply to BJF's sims,which I simply said under the conditions he used for simulations of win-rate,score,SCORE or whatever he wishes to call it. The variance, may I say, is HUGE for 6 deck when compared to single-deck. I certainly hope we dont need Cacarulo's aid to verify this,do we?

Under the conditions of simulations BJF used, dollars lost and won during 6 deck sessions will be about 3 times higher than single-deck,give or take a few hundred bucks. It's the spread needed at 6 deck to achieve the same win rate as single deck that has caused variance to increase dramatically. The frequency of TC'c had little to do with variance. So basicly if SSR is trying to achieve the same win rate going from single deck to 6 deck and ask the question of variance being higher at 6 deck,the answer is simply,yes it is. I read a few of SSR's post and this seems to probably be what I thought he was implying, but confusing everybody with too many variables and simulations. If I'm wrong,I'm sure SSR will put me in my place.

Good Ground Hog Day

[Parker]

My reply wasn't really aimed at you personally. I know you understand this stuff.

Rather, it was an attempt to summarize the whole thread, in simple language, for the benefit of any beginners who might still actually be following it, and to show that what appears to be a contradiction isn't really one at all.

It's the spread needed at 6 deck to achieve the same win rate as single deck that has caused variance to increase dramatically.

Or to put it even more simply, we see bigger swings for the simple reason that we are putting a lot more money on the table -- not because the shoe game is inherently more volatile than the SD game.

This is, after all, the beginner's page. :-)

[Don Schlesinger]

> It's the spread needed at 6 deck to achieve
> the same win rate as single deck that has
> caused variance to increase dramatically.
> Or to put it even more simply, we see bigger
> swings for the simple reason that we are
> putting a lot more money on the table -- not
> because the shoe game is inherently more
> volatile than the SD game.

Too many times during this much longer than necessary thread, we've talked about SCOREs and variance and volatility as if they were completely separate concepts, not in some way linked -- which simply isn't true.

SCORE is the square of DI, which, in turn, is simply the Sharpe Ratio for a game, or EV/SD.

So, let's say that we all agree, for a given set of rules, spread, etc., that the single-deck game has the superior SCORE to the shoe game. It is, inherently, the better game. But now, you somehow force the two EVs to be identical, through size of unit, manipulation of spread, or whatever. So now, the two numerators (EV) are the same, yet we know that the DI for the single-deck game is superior to that of the shoe. That could only be true (since EVs are forced to be identical) if the SD of the single-deck game is smaller than the SD of the shoe game. This isn't rocket science!

But, again, as Parker and so many others have now stated, almost ad nauseam, this is clearly not the way to compare the volatility of the two games, nor (at least in my mind) what our original questioner had in mind.

I believe we've beaten this question to death. It would be just wonderful if we could all move on. :-)

Don