Zenfighter: Mcdowell's controversy. What a riot!

[Zenfighter]

Errata corrections published before Snyder?s review of McDowell?s BJAP.

Errata for Blackjack Ace Prediction

Page 114, Line 15: At this point we invoke Snyder?s rule of thumb?the player and the dealer share the Aces 50/50. In this case, that means the player and the dealer get three additional aces each. The probability of the Ace ?hitting the money? P(h) and the probability of the dealer getting the Ace by accident P(d) become 0.10 while P(m) is reduced from 0.87 to 0.80.

Page 114, Line 25: Assuming E1 = +0.51, E2 = -0.34, E3 = -0.005 h = 0.10, d = 0.10 m = 0.80
E(X) = (+0.51 X 0.10) + (-0.34 X 0.10) + (-0.005 X 0.80)
= +0.051 - 0.034 - 0.004
= +0.0130

Note, if the dealer can be prevented from getting the Ace, the player?s expectation is:
E(X) = (+0.51 X 0.13) + (-0.34 X 0.07) + (-0.005 X 0.80)
= +0.0663 - 0.0238 - 0.004
= +0.0385

Michael
Dalton
Digitally signed by Michael Dalton
DN: CN = Michael Dalton, C = US,
O = Blackjack Review Network, OU
= Spur of the Moment Publishing
Reason: I am approving this
document
Date: 2004.10.24 16:40:23 -04'00'

Inferences:

1) Arnold published his review without being aware of the author?s changes, which were available for free through the publisher?s web. Note that 1.3% is not 4.2% precisely. This last figure was used extensively during his McDowell?s folly review as one of his argumentative weapons.

2) Unfortunately David 7-3 formula still remains inaccurate, due mainly to the E3 value underestimation, as I tried to explain a reader below.

Both figures, that is, sharing the final probabilities of getting the keyed ace with the dealer and preventing him from getting it, can be extracted accurately with an exact combinatorial and/or simulated approach.

Moral? Math and hurries aren?t good partners.

Hope this helps

Sincerely

Zenfighter.

[Norm Wattenberger]

this entire brouhaha was due to one person not reading the errata. I admit that I saw the errata awhile back but never looked at it closely myself. But, my interest was never in page 115. I doubt anyone can accurately formulize the EV for this technique. (That?s why we?re still stuck with sims.) I think the book?s value is in the discussions on technique and breaks that you will find in no other public document anywhere. And I still recommend the book.

The posts on this book have been quite out of the ordinary. Words like fraud, sleaze, and Jerry Patterson have been carelessly thrown about by people that have never spoken to the author. One poster even wrote a long mathematical critique while admitting he?d never actually seen the book!

I shudder to think where we would be today if every first time BJ author?s first edition was vilified in such a manner immediately after release. Every first edition in BJ contains areas in need of improvement. I dare say there would be nothing but progression books. Perhaps in future reviewers will take more time and at the least read all of the material.

[Bettie]

FYI, a copy of the errata is sent with every copy of the book bought from RGE.

Thanks,
Bettie

[Don Schlesinger]

Thank you, Zen, for taking the time to set the record straight. Of course, don't expect any satisfaction from your post; AS will concoct some lame excuse as to how he never read the errata, but, of course, he won't apologize for jumping the gun.

His review wasn't about providing accurate information to prospective readers. It was about 1) grabbing an opportunity to -- unjustly, of course -- lambaste those of us who said good things about a fine book, and 2) plant the seeds of doubt as to whether one could get the edge claimed, so that those who would contemplate sequencing might have second thoughts. The latter, of course, is what I wrote about in my own review, when I presaged: "I have a feeling that the relatively small group of players already aware of the techniques that McDowell describes are not going to be happy that he has gone 'mainstream' with the information."

As Snyder was clearly one of those people, what better way to protect his "turf" than to attack the book in an attempt to nip in the bud the plans of aspiring players to try this advantage-play technique.

Ah, intellectual honesty -- ya gotta love it.

Don

[Parker]

Since I am not a math guru or a tracker/sequencer, I have (mostly) refrained from commenting on the McDowell book.

However, I cannot help but noting that my 1998 edition of Blackbelt in Blackjack came with an errata sheet. Had I decided to learn the Red 7 count and ignored the errata sheet, I would have been counting aces as +1 instead of -1, and using the wrong starting count (IRC) for single deck games.

Needless to say, the EV figures quoted in the book for Red 7 are wildly inaccurate if the errata sheet is not taken into consideration.

Despite this rather significant error, the 1998 edition of Blackbelt in Blackjack is a classic, groundbreaking work, and is now a sought-after collector's item. Perhaps my memory is fading, but I do not recall its auther ever being crucified for these errors.

I also note that in the back of my 1998 edition of Blackbelt in Blackjack, under "Recommended Source Materials," I find Blackjack Attack, by Don Schlesinger.

[Myooligan]

Quote from Zenfighter's post above: "Unfortunately David 7-3 formula still remains inaccurate, due mainly to the E3 value underestimation, as I tried to explain a reader below."

The things you guys are saying, they'd be fair enough if the errata sheet corrected the problem, and Arnold was criticizing something that had already been corrected. But the formula still contains a significant error. So as it stands, Arnold is critiquing an error that you yourselves acknowledge. If you read his post, not ones by Yoko or Blackjack Historian or anyone else, I think you'll agree that he is writing courteously. You guys are responding by criticizing him. He's attacking an argument; you're attacking a person.

I don't know the history of the personal conflicts between you guys, and it's not my business. I don't know why it's even being discussed here. Even people without integrity are capable of contributing valuable ideas. But we should be discussing the ideas, not the people they came from.

If the picture I'm getting from you guys is accurate -- that Arnold has some sort of army of posters and/or pseudonyms he uses to attack Don, while appearing polite and respectful when he posts under his own name. . . with due respect, Don, but who cares? When someone posts under an established name, like Norm or Don or Zenfighter, I trust their assumptions and quoted numbers. If one of them was trying to discredit claims made by another author, I'd give them some attention. But when some unknown figure like Blackjack Historian makes a claim, I don't extend any trust at all. And seriously, how long does it take a reader to figure out how to skip over some raving poster like Clarke Cante?

As I consider you my friends, I have to say that you aren't coming across as being motivated by "the truth, regardless of who it compliments or even what mistakes it may reveal," rather than "a personally motivated disagreement," to quote Viktor.

I mean no ill will and hope these comments are well-received.

sincerely,
Myoo

[Norm Wattenberger]

All books contain some estimates and some assumptions and some errors. Arnold is attempting to state that the entire book is a useless fraud. He does this first by ignoring the errata and pointing out an error already corrected by the author. The author's corrected number is closer than Arnold's. Neither is exact because there is no way to exactly formulize EV for this technique.

ALL of the posts I have seen completely ignore qualifications and particulars clearly stated in paragraph after paragraph in the book. Read the book for yourself and you will see this.

But you seem now to be asking us to write an entire new book in response. McDowell has taken the science to a point beyond its previous point. It is not a complete description of the game of BJ. When that is written, we can close down all the forums.

[Myooligan]

> But you seem now to be asking us to write an
> entire new book in response.

no no no didn't mean to give that impression at all. You guys have been extremely generous to us all and I am grateful.

Actually, I got the answer I was after at the beginning of this thread. My continued posting wasn't intended to push any sort of agenda forward. I just found the debate stimulating, at several levels. For instance, my last post wasn't really about BJAP at all. It was about criticizing ideas rather than people.

But I do understand that there is no exact formula, and I also understand why that makes the error less significant than it had seemed to me originally.

[ET Fan]

Is this the probability one specific ace will hit one specific spot (as in the player's first card or the dealer's upcard)? If so, it's quite a change from the premise laid out according to Snyder, where the total probability of getting any ace on each of these spots was 0.13. In that case, the probability of getting one tracked ace muct be 0.062 (for four decks) if all the other (untracked) cards are evenly distributed.

That would mean McDowell increased the probability of getting an ace, in his errata, yet decreased the EV to the player, in what looks like a very simple calculation, the way he did it.

But if 0.10 represents the total probability of any ace going to player's card1 or the upcard, it's even worse! Plus the calculation is plainly wrong that way.

Either way, it's a change in the premise, and really doesn't address Snyder's critique. If Snyder was just wrong in stating McDowell's premise, then you should just say that.

ETF

> Errata corrections published before Snyder?s
> review of McDowell?s BJAP.

> Errata for Blackjack Ace Prediction

> Page 114, Line 15: At this point we invoke
> Snyder?s rule of thumb?the player and the
> dealer share the Aces 50/50. In this case,
> that means the player and the dealer get
> three additional aces each. The probability
> of the Ace ?hitting the money? P(h) and the
> probability of the dealer getting the Ace by
> accident P(d) become 0.10 while P(m) is
> reduced from 0.87 to 0.80.

> Page 114, Line 25: Assuming E1 = +0.51, E2 =
> -0.34, E3 = -0.005 h = 0.10, d = 0.10 m =
> 0.80
> E(X) = (+0.51 X 0.10) + (-0.34 X 0.10) +
> (-0.005 X 0.80)
> = +0.051 - 0.034 - 0.004
> = +0.0130

> Note, if the dealer can be prevented from
> getting the Ace, the player?s expectation
> is:
> E(X) = (+0.51 X 0.13) + (-0.34 X 0.07) +
> (-0.005 X 0.80)
> = +0.0663 - 0.0238 - 0.004
> = +0.0385

> Michael
> Dalton
> Digitally signed by Michael Dalton
> DN: CN = Michael Dalton, C = US,
> O = Blackjack Review Network, OU
> = Spur of the Moment Publishing
> Reason: I am approving this
> document
> Date: 2004.10.24 16:40:23 -04'00'
> Inferences:

> 1) Arnold published his review without being
> aware of the author?s changes, which were
> available for free through the publisher?s
> web. Note that 1.3% is not 4.2% precisely.
> This last figure was used extensively during
> his McDowell?s folly review as one of his
> argumentative weapons.

> 2) Unfortunately David 7-3 formula still
> remains inaccurate, due mainly to the E3
> value underestimation, as I tried to explain
> a reader below.

> Both figures, that is, sharing the final
> probabilities of getting the keyed ace with
> the dealer and preventing him from getting
> it, can be extracted accurately with an
> exact combinatorial and/or simulated
> approach.

> Moral? Math and hurries aren?t good
> partners.

> Hope this helps

> Sincerely

> Zenfighter.

[Sun Runner]

Respectfully, and seriously trying to stay out of the mud let me say this.

I don't know what the 0.10 represents and I actually own and have read the book twice!

There is not much doubt that Arnold Snyder and those he knows have the ability to read this book, review this book, and correct many of the flaws it may contain.

I would have been more compelled, to accept at face value, his review of the book had it not been preceded for several days (months actually) by post after post of his (yes, his) "Don Schlesinger is a pretender to the Ill 18 throne" and ".. ha, ha Don Schlesinger is an idiot because he endorsed this book."

Had his purpose been to 'protect the players' he probably would have contacted some people, read the erratta, and moved methodically forward. For that I would have been grateful. His actions seemed to say he had other issues than writing a review and 'protecting the players.'

I'm sorry. His credibility is shot with me. For many reasons, I wish it were not.

(no need to respond; I just picked this place as a posting point and it is not directed towards you neccessarily.)

[ET Fan]

... where the man can't control anything the woman says, or vice versa? Do you think less of the more controlled spouse? I don't.

You see some sort of huge conspiracy, masterminded by Snyder. I just see people acting like people. In fact, I see people using different handles to keep their identities from Snyder. I see Snyder very recently proclaiming Schlesinger "an authority," and including his name with the likes of Thorp and Forte. I see Snyder's friends rushing to defend Arnold because they feel he was rooked on a business deal. You've never seen that? You've never noticed that different people have different ethical standards in business, with resulting feathers rustled?

Now, I am an ET fan, and a Schlesinger fan, and a Snyder fan. You can all stop throwing rocks at each other, and just throw 'em at me.

ETF

> post after post of his (yes,
> his) "Don Schlesinger is a pretender to
> the Ill 18 throne" and ".. ha, ha
> Don Schlesinger is an idiot because he
> endorsed this book."

[Zenfighter]

If so, it's quite a change from the premise laid out according to Snyder, where the total probability of getting any ace on each of these spots was 0.13.

Believe me ETF; you won't be able to fully understand what's really going here, unless you get a copy of David's book by yourself.
Anyway I'm forced to address you to McDowell's table 3-2.

Card gaps for a two-riffle shuffle. (Page 50)

McDowell extracted this table (at the 95% confident level) based on Thorp's former shuffling analysis. (Despite the curve looking somehow skewed, it's almost bell-shaped and thus his inferences applied correctly here)

The most important statement wherein, is that:

Three cards in the final order most frequently separate two cards that were originally neighbours in the initial order

Extracted from the mentioned table, enters the now famous 38.2 hit rate. After the deductions for false key and broken sequences, let's take the pessimistic road:

38.2 -15 - 18 = 5.2 extra keyed aces will hit the money.

As you can see I've thrown to the wastepaper basket the refinement of memorizing e.g. up and/or down key cards plus awkward alignments.

Thus, we can make the elementary inference that:

5.2/2 = 2.6 and

7.7 + 2.6 = 10.3 aprox. 10 aces for every one.

But wait; if and only if you're so naive as to apply this methodology "flirting" around the mean of Table 3-2 distribution. (The second value yields a 17.6 hit rate)

In plain English: The EV will sink dramatically if you insist to, e.g. heads up against the dealer. A bad choice, frankly. Note that Snyder's insistence with this solo example flood around his whole review. A good weapon to badmouth David's math at the same time!

Moral; the more players at the table the better. (To steer the keyed aces).

In other words, these techniques work at best under crowded/semi crowed conditions where back betting is allowed and encouraged at the same time. (e.g. Europe/Australia) Study carefully Table 3-2 and you'll forced to agree.

Hope this helps

Zenfighter

[Sun Runner]