blackjack crusader: Grosjean VS Cacarulo on 10,10 Insurance

[Rukus]

Thanks again Don, and i apologize if i am truly missing something or causing you headaches . But that said, I must apologize for continuing to belabor the point here...

> No, it isn't. Just as r-a indices can be different
> depending on what percent of your bank is risked on
> the hand, the same can be trueof insurance r-a
> indices. They could be different depending on the
> amount of the original wager, as a percent of total
> bank. And, obviously, the amount of the original wager
> immediately impacts the amount of the insurance wager.

100% agreed with this point. the fraction of your BR bet on the main hand affects what you bet on the insurance and can affect what we are agreeing to call the "traditional" index.

> No, that isn't true. If it were, why would all the
> indices for the different two-card holdings of the
> various hands be different?? To calculate the
> variance, you obviously have to include the result of
> the main hand. How else could you get different
> variances, if you were just considering whether the
> dealer had a natural or didn't? I don't think you
> understand this point.

I do not agree that to calculate variance of the sidebet you need to include the results of the main hand. see my example below of someone just standing behind a table and ONLY playing the insurance bet when he feels like it. his EV and variance will not be tied to the whether the main hand he is back-betting wins. it cannot be so since insurance is checked for and bets paid/collected before the main hand is even played.

> I believe you are wrong.
> See above. I believe your premise is wrong.
I am trying to confirm this, and would love to know whether or not i am wrong here. this can answer the question, if we know what EV and variance Cac or even Norm/CVData use. It is my thesis that they are using the insurance bet's independent EV and variance (that i describe below can be obtained by just simulating a player only playing the insurance bet but not the main hand). You say I may be mistaken. I would LOVE to know for sure if you can confirm with Cac and/or Norm.

> Of course. But, I can't believe that you think that
> Cac didn't take this into account.

This is exactly what I would like to have clarified if you can be in touch with Cac and confirm.

I think Cac takes into account the main hand only to say, "ok i see a TC of, say 3, but i know i am holding two tens in my hand, which is different than me seeing a TC of 3 and holding no tens in my hand". thus the probability the dealer is holding a 10 in the hole differs for a given TC depending on what you are holding in your own hand. that is what i believe Cac uses the main hand's information for, purely for determining the change in probability of dealer holding a 10 in the hole as well. This is part of what i am trying to confirm with Cac and/or Norm.

i guess what i am TRULY asking is this: is the EV and variance Cac is using in his sims coming from the main hand or just the side bet. in my mind, it is perfectly understandable to believe that when looking at when to make a side bet you would just look at the EV of that side bet and the variance of just that side bet. i would like confirmed whether this is what Cac has done. if it is what he has done, than Grosjean's point has not been addressed.

what you are saying i do not understand is what i am arguing for: the side bet itself does have its own EV and variance.

imagine we are in a casino that allows someone who just stands behind a table without playing a hand himself to take insurance on another person's hand. his EV and variance will be purely based on the insurance side bet.

agreed? if you say i am wrong on this point and say that someone purely playing the insurance bet (but not the main bet) does not have an EV and variance different from someone playing a regular blackjack hand, then you can stop reading and i will drop the argument.

but i am maintaining that since this player is only betting on the side bet, not the main bet, his wins and losses are not tied to whether the main bettor wins or loses. It is this "independent" EV and variance of someone only playing the insurance side bet that i believe, and would love to have confirmed, Cac is using in his index calculations. as a matter of fact, this SHOULD be the EV and variance he looks at while calculating his indices according to what we agree is the "traditional" way to calculate indices.

What i am saying is now take a typical player who plays the main hand and the insurance bet at times. his EV is a combination of the EV from playing the blackjack hand plus the EV from playing the insurance side bet and his variance is a combination of the variance from playing the main blackjack hand plus the variance of the insurance side bet itself. I think Grosjean is commenting that it is this "global" or "total" EV and variance that should be taken into account when determining a risk-averse insurance index.

> I don't think James has done anything different from
> what was already done.

He must be doing something different if he is recommending taking insurance "earlier", ie at a lower TC, than the index (for reasons other than heat diffusion) when holding say 10,10 vs Cac's original sims that say take insurance "later" than the normal insurance index for that same hand!

Thanks again Don,
Rukus

[blackjack crusader]

> Thanks again Don, and i apologize if i am truly
> missing something or causing you headaches . But
> that said, I must apologize for continuing to belabor
> the point here...

> 100% agreed with this point. the fraction of your BR
> bet on the main hand affects what you bet on the
> insurance and can affect what we are agreeing to call
> the "traditional" index.

> I do not agree that to calculate variance of the
> sidebet you need to include the results of the main
> hand. see my example below of someone just standing
> behind a table and ONLY playing the insurance bet when
> he feels like it. his EV and variance will not be tied
> to the whether the main hand he is back-betting wins.
> it cannot be so since insurance is checked for and
> bets paid/collected before the main hand is even
> played.
> I am trying to confirm this, and would love to know
> whether or not i am wrong here. this can answer the
> question, if we know what EV and variance Cac or even
> Norm/CVData use. It is my thesis that they are using
> the insurance bet's independent EV and variance (that
> i describe below can be obtained by just simulating a
> player only playing the insurance bet but not the main
> hand). You say I may be mistaken. I would LOVE to know
> for sure if you can confirm with Cac and/or Norm.

> This is exactly what I would like to have clarified
> if you can be in touch with Cac and confirm.

> I think Cac takes into account the main hand only to
> say, "ok i see a TC of, say 3, but i know i am
> holding two tens in my hand, which is different than
> me seeing a TC of 3 and holding no tens in my
> hand". thus the probability the dealer is holding
> a 10 in the hole differs for a given TC depending on
> what you are holding in your own hand. that is what i
> believe Cac uses the main hand's information for,
> purely for determining the change in probability of
> dealer holding a 10 in the hole as well. This is part
> of what i am trying to confirm with Cac and/or Norm.

> i guess what i am TRULY asking is this: is the EV and
> variance Cac is using in his sims coming from the main
> hand or just the side bet. in my mind, it is perfectly
> understandable to believe that when looking at when to
> make a side bet you would just look at the EV of that
> side bet and the variance of just that side bet. i
> would like confirmed whether this is what Cac has
> done. if it is what he has done, than Grosjean's point
> has not been addressed.

> what you are saying i do not understand is what i am
> arguing for: the side bet itself does have its own EV
> and variance.

> imagine we are in a casino that allows someone who
> just stands behind a table without playing a hand
> himself to take insurance on another person's hand.
> his EV and variance will be purely based on the
> insurance side bet.

> agreed? if you say i am wrong on this point and say
> that someone purely playing the insurance bet (but not
> the main bet) does not have an EV and variance
> different from someone playing a regular blackjack
> hand, then you can stop reading and i will drop the
> argument.

> but i am maintaining that since this player is only
> betting on the side bet, not the main bet, his wins
> and losses are not tied to whether the main bettor
> wins or loses. It is this "independent" EV
> and variance of someone only playing the insurance
> side bet that i believe, and would love to have
> confirmed, Cac is using in his index calculations. as
> a matter of fact, this SHOULD be the EV and variance
> he looks at while calculating his indices according to
> what we agree is the "traditional" way to
> calculate indices.

> What i am saying is now take a typical player who
> plays the main hand and the insurance bet at times.
> his EV is a combination of the EV from playing the
> blackjack hand plus the EV from playing the insurance
> side bet and his variance is a combination of the
> variance from playing the main blackjack hand plus the
> variance of the insurance side bet itself. I think
> Grosjean is commenting that it is this
> "global" or "total" EV and
> variance that should be taken into account when
> determining a risk-averse insurance index.

> He must be doing something different if he is
> recommending taking insurance "earlier", ie
> at a lower TC, than the index (for reasons other than
> heat diffusion) when holding say 10,10 vs Cac's
> original sims that say take insurance
> "later" than the normal insurance index for
> that same hand!

> Thanks again Don,
> Rukus

Cacarulo composition dependent RA insurance 10,10 vs dealer A at TC 4

Griffin
"Insure a Good Blackjack Hand part 2"
If I understand. At precisely the insurance index (borderline decision) insure 20, 19, 18, 11, 10, 9 in order to reduce variance.
and
Grosjean page 12 "beyond counting"
"if the insurance count is exactly 0, you will lower your variance by insuring any soft hand, any 8-11 and 18-21.

These seem to contradcit each other?
Cac as opposed to Griffin and Grosjean

Let's assume optimal betting. However, Don I believe you state in BJA 3 that whatever fraction of kelly is used the RA indices would remain the same. page 374 3rd paragraph.

Don thanx for your time. I am sure we are driving you to the brink!

[Don Schlesinger]

Stewart Ethier has edited a wonderful new book entitled "Optimal Play: Mathematical Studies of Games and Gambling," in which there are new papers published by some of our best theoreticians.

The first paper is "Advanced Insurance Play in 21: Risk Aversion and Composition Dependence," by R. Michael Canjar. I read it awhile ago, when Stewart sent me the book, but would have to reread it to best answer the questions in the above discussion.

In any event, all the answers -- and then some! -- can be found in this article. In addition, there is a table giving the adjustments to the e.v-maximizing Hi-Lo insurance indices, when hand composition and risk-aversion are BOTH taken into account, for every starting holding!

I'll try to reread the article, but, in the meantime, for 6 decks, S17, DAS, and a player T,T, the CD adjustment is to ADD 0.26, but the RA/CD index adjustment is to SUBTRACT 0.3 for a 2% wager and subtract 1.1 for a 5% wager. Of course, the Hi-Lo standard index is 3.0.

Hope this helps a little.

Don

[rukus]

> Stewart Ethier has edited a wonderful new book
> entitled "Optimal Play: Mathematical Studies of
> Games and Gambling," in which there are new
> papers published by some of our best theoreticians.

> The first paper is "Advanced Insurance Play in
> 21: Risk Aversion and Composition Dependence," by
> R. Michael Canjar. I read it awhile ago, when Stewart
> sent me the book, but would have to reread it to best
> answer the questions in the above discussion.

> In any event, all the answers -- and then some! -- can
> be found in this article. In addition, there is a
> table giving the adjustments to the e.v-maximizing
> Hi-Lo insurance indices, when hand composition and
> risk-aversion are BOTH taken into account, for every
> starting holding!

> I'll try to reread the article, but, in the meantime,
> for 6 decks, S17, DAS, and a player T,T, the CD
> adjustment is to ADD 0.26, but the RA/CD index
> adjustment is to SUBTRACT 0.3 for a 2% wager and
> subtract 1.1 for a 5% wager. Of course, the Hi-Lo
> standard index is 3.0.

> Hope this helps a little.

> Don

Yes this definitely helps. Would love to get my hands on this book. From what you wrote above, Canjar's paper seems to agree with Grosjean's concept of LOWERING the index (by varying amounts, depending on fraction of BR originally bet) when holding a strong hand such as 10,10, which would be in contrast to Cac's original RA results for 10,10 found in the "Best of the Masters" section of the boards.

Thanks again Don,
rukus

[Don Schlesinger]

I have written to Cac and to Zenfighter, inviting them to look at this thread. If they have anything to add, they will surely post here.

In the meantime, I saw nothing in Beyond Counting to imply that James was doing something different. When you take insurance early, you may or may not reduce variance. Clearly, if the r-a index is higher than the normal index, then taking insurance early has just the opposite effect: it increases variance!

I understand all of your arguments, and I understand the concept of a person not playing the main hand but just taking insurance. Of course his results have nothing to do with the main hand. But, yet again, I do NOT believe that this is what Cac is doing.

Either way, it will be great to hear from him here.

Don

[rukus]

> I have written to Cac and to Zenfighter, inviting them
> to look at this thread. If they have anything to add,
> they will surely post here.

> In the meantime, I saw nothing in Beyond Counting to
> imply that James was doing something different. When
> you take insurance early, you may or may not reduce
> variance. Clearly, if the r-a index is higher than the
> normal index, then taking insurance early has just the
> opposite effect: it increases variance!

> I understand all of your arguments, and I understand
> the concept of a person not playing the main hand but
> just taking insurance. Of course his results have
> nothing to do with the main hand. But, yet again, I do
> NOT believe that this is what Cac is doing.

> Either way, it will be great to hear from him here.

> Don

Thanks for bearing with me Don, I appreciate it! I look forward to hearing from Cac as well.

Rukus

[Zenfighter]

Don!

I've got your mail yesterday. Unfortunatelly, I'm abroad
at present without any technical stuff handy. In any case,
I do think that my article "Even money. Fundamentals and excerst from TOB"
(just scroll down this page until reaching it) may add a little bit of more light, for BJ Crusader and Rukus.

Sincerely yours

Zf

[Rukus]

> Don!

> I've got your mail yesterday. Unfortunatelly, I'm
> abroad
> at present without any technical stuff handy. In any
> case,
> I do think that my article "Even money.
> Fundamentals and excerst from TOB"
> (just scroll down this page until reaching it) may add
> a little bit of more light, for BJ Crusader and Rukus.

> Sincerely yours

> Zf

Zf, thank you very much for your reply despite being out of the country. However, scrolling down, I am not able to see a link or anything to your article. Am I missing something?

Also, does anyone know if UNLV Reno is still selling a copy of the book Don mentioned for $59? I haven't seen it available anywhere else, but there is still an old-fashioned order form on the UNLV website...

Thanks again,
Rukus

[Don Schlesinger]

> Zf, thank you very much for your reply despite being
> out of the country. However, scrolling down, I am not
> able to see a link or anything to your article. Am I
> missing something?

Apparently. It's less than halfway down my page.

Don

[David Spence]

> Zf, thank you very much for your reply despite being
> out of the country. However, scrolling down, I am not
> able to see a link or anything to your article. Am I
> missing something?

I actually don't see the link either. I'm not sure what special powers Don possesses that enable him to see it, but apparently they're ones you and I lack :-)

> Also, does anyone know if UNLV Reno is still selling a
> copy of the book Don mentioned for $59? I haven't seen
> it available anywhere else, but there is still an
> old-fashioned order form on the UNLV website...

I bought a copy from the Gambler's Book Shop in Las Vegas, but the website says they're out of stock. It might be worth calling (800-522-1777), though.

David

[blackjack crusader]

> I actually don't see the link either. I'm not sure
> what special powers Don possesses that enable him to
> see it, but apparently they're ones you and I lack :-)

> I bought a copy from the Gambler's Book Shop in Las
> Vegas, but the website says they're out of stock. It
> might be worth calling (800-522-1777), though.

> David

Go back to the main "Theory and Math page" and then scroll down. It's about half a page down.

[Don Schlesinger]

> Go back to the main "Theory and Math page"
> and then scroll down. It's about half a page down.

Is that not what I said?? In any event, it's not a link; it's the original POST that Zenfighter made, and it's simply further down on this page.

Don