One Incontrovertible, Unequivocal, Undeniable Fact Which Refutes the Diary

[JeffHamm]

I had a colleague who was born on the same day as me which was a bit weird. Amazingly enough, we both had one child, and they too were born on the same day. Na noo na noo?

Well, not exactly. Because hundreds of thousands of people are being born each day (207,000 have been born today already, 1pm UK time), it is inevitable that we share our date of birth with hundreds of thousands of people amongst whom it is extremely likely that at least one other would have their only child on the same day we did. So sounds staggeringly unlikely, but is probably very common.

What was staggeringly unlikely, however, was that she and I would 1) ever meet, and 2) uncover that seemingly-outlandish stat. Perspective is everything, it would appear.

Whatever happened to Sir Lenny, by the way?

Ike

Not really that unlikely actually. Take a room with 30-35 people in it and the odds are in your favour to bet two of them at least have the same birthday (not including the year). I grew up in a small town of around 4500 people. I had the same birthday as two of my friends, though they were 1 year older. So there's 3 who have the same birthday, two if you include the year, all three meet, etc.

And same for you. And probably many others here on the boards.

As I say, a lot of things about probabilities are not intuitive and show common sense is wrong.

(you work out the odds of gathering 30 people and for them not to have a birthday in common; to simplify that divide the probability equally over the year, but that's not true I don't think, so to get the real probability requires a lot of birth information, and that takes all the fun out if it). Oh, if you want the year to be the same, then gather all the kids in a common grade at a school. You'll have a few that share birthdays and they probably even know each other.

The also having a child with same birthday is cool though, and that is probably much less common. So that's so improbable I'll hypothesize that you two must have planned it that way. I mean really, of all the days in your adult life that your child could have been born, and hers could have been born, it just happened to be the same day? Let's see, about what, 35 years for fertility (your female friend) so the combination has a 1 in 163.4 million chance (making the floorboards and phonecall absolutely run of the mill common). So clearly the two of you discussed that and made it happen. Just keep this in mind when you start to think about relating post hoc probabilities for known events to evaluating hypotheses that only occur to us after we know the events happened.


- Jeff

[rjpalmer]

Dear Readers,

If James Maybrick's floorboards came up for the first time on the record on March 9, 21992 (20,000 years later than they did) and on the same day, some futuristic (OMG!) Mike Barrett rang some futuristic Rupert Crew asking if they were interested in James Maybrick's Jack the Ripper diary, Jeff Hamm would not be even vaguely surprised. Why? Well, because life is constantly throwing-up improbable events by chance alone.

Hi Ike.

On thinking it over, I have realized that this is--hand’s down--the craziest comment you’ve made all week, but very useful in that it neatly exposes the fundamental flaw that hides within your statistical analysis.

And I even have hope that you will finally be able to see why.

For some strange reason, you seem to believe that Jeff should be overwhelmingly more impressed if the electricians lifted the floorboards (and futuristic Barrett phoned with the Diary) on 9 March 21,992 than when the exact same two events occurred on 9 March 1992.

But this is obviously ludicrous. It’s still the same exact coincidence.

What impresses Caz, Keith, and Erobitha, etc. is the fact that the two events (the flooboards/the phone call to the literary agency) coincide. That they happened on the same day—the same moment in time—is the whole point. That is the coincidence. That is what appears suspicious and strange and ‘worthy of investigation.’

The intervening years are entirely irrelevant. They play no part in the supposedly astonishing coincidence.

Yet, in your crazy version of statistics, the passing years ARE relevant. It’s now clear that you really believe this, hence the reason you badgered Jeff with the year 21,992.

Think it through this time, mate. Think it through.

For the sake of argument, if Nurse Yapp phoned with the Diary of Jack the Ripper on May 29, 1889 and it was found that the floorboards of Battlecrease were lifted that same day, Caz, Keith, etc. would still find the two events to be suspicious as hell. They might even find them MORE suspicious. It’s the two events occurring close to one another that raises alarm bells. But in your crazy system, the coincidence would only amount to 18 to 1---the same meager odds that insulted you when Lord Orsam used them. Because only 18 days had passed between Yapp’s phone call and Maybrick’s death on the 11th.

And, by your same thinking, if the Yapp/floorboard coincidence instead happened on May 29, 1891—even though it is again THE SAME TWO ACTIONS and the SAME SUSPICIONS ARE aroused, it would now be a startling 759 to 1 coincidence.

And, of course, you have drummed into our heads for two weeks that if the same two events occurred on 9 March 1992, suddenly the odds are 37,577 to 1. Your sacred formula.

Sorry mate, but even a school-boy can see this is crazy.

It is crazy because the passing of time has no relevance to the ‘coincidence’ that Keith and Caz and everyone is noticing. Indeed, it is the very fact that these two events appear to happen on the same day, and outside the sweep of time, that makes people wonder if they are linked.

Yet you keep irrelevantly injecting the passing of time into your calculations as a relevant factor--the date of Maybrick’s death---11 May 1889---and then counting forward until you reach 37, 577 days, thus making your entire statistical analysis irrelevant and flawed and curiously circular in a very peculiar sort of way.

Surely you can see this by now?

R P

[JeffHamm]

I have a lot of time for you, Jeff. I respect your analytical abilities and your methodical approaches and ideas. I think for the crimes of JtR as a whole you offer great value. In particular, your analysis on geographical profiling was to me quite extraordinary and hugely interesting.

My issue here is thus; Ike at no stage claimed it was proof of anything. The values he cited cannot be regarded as irrelevant, but nor can the results of the calculation can be regarded as absolute evidence. It is simply very interesting. It provides an interesting starting point for further discussions and analysis. He has not claimed ANYTHING. He is merely calculating the odds of two events linked by James Maybrick as occurring on the same day. He has not made any grand declarations.

Can you not at least give him credit for being correct in principle thus far?

Hi erobitha,

I have, a few times, completely agreed that the probability of everyday events are actually extremely low, and have indicated that it would not be a shocker to find that yet again. I've suggested if all one wants to do is examine the improbability of things that happen, then I would argue his flat distribution model needs revising, etc.

So if that is all he is interested in, we agree, life is improbable.

The only thing I've been saying is that those probabilities are irrelevant with regards to the diary provenance, and no matter how rare the above is it cannot be misconstrued as support for anything diary related.

Some of Ike's statements suggest he sees the low prob. If those events as indication they must be related or that the low probability somehow is surprising. That's where he is wrong. All events, when we calculate them this way, end up with low probabilities, etc If, however, he recognises that no matter how improbable his calculation is, that it means squat all with respect to diary coming from the floorboards, then we've agreed all along.
.- Jeff

[Iconoclast]

Can you not at least give him credit for being correct in principle thus far?

Hi ero b,

It's incredibly kind of you to stick your neck on the block in my defence (I've noted it, mate, even if your motivation will be seen in other quarters as simply the instincts of a 'true Maybrickian').

I don't think Jeff believes probability theory has a place in this example. His posts are fulsome regarding the premise for experimentation and yet are essentially void of reference to simple probability theory. Maybe I'm just getting too old for this game! My degree was 35 years ago so perhaps the study of statistics has moved on since then, and moved on in such a way that there is no longer a place for the basic tenets of simple probability theory; which would be seismic for me as we were taught that statistics only exists due to the predictability of probability theory and that statistical tests could not be taught until probability theory was properly understood. Maybe the world has changed, but 35 years ago I believe my simple question regarding three known facts would be readily accepted into the welcoming arms of simple probability theory.

The evidence suggests that Jeff does not teach probability theory, perhaps for the reasons above - it no longer has a role to play and statistical analysis is the deep end into which all must now jump. And yet Jeff had no hesitation in delving into his pocket when it suited his argument and pulled out his 'fair' coin. That's probability theory right there, 101, bang to rights, etc., but my example apparently wasn't. I can only assume that 1) time has marched on and probability theory has become so nuanced as to no longer prove of use except in strictly 'fair' examples (though, of course, if we wanted to we could also come up with variables which might favour one side of the coin over the other which would presumably immediately nullify even our 'fair' example as an example), or 2) it's still useful and I was just plain wrong, or 3) Jeff has subliminally slipped into the strong anti-Maybrick flavour of this Casebook (and other forums) and therefore he didn't realise that he does indeed have a dog in the race and it wasn't wearing Maybrick's colours. The mind can play remarkable tricks on us, apparently.

Anyway, I appreciate the sentiments, ero b.

Your old mucker,

Ike

[erobitha]

Hi Ike,

I've used your 1/37000+ because the discussion has primarily been between you and I, but I've also made it clear it doesn't matter what value one argues for;. No matter what value one argues for is still to argue for an irrelevant value. These probabilities, whether high or low contribute nothing to the evaluation of the hypothesis. It's like me saying Joe Bloggs was JtR and my evidence is my shoe size is 10.5, and we debate what system if shoe sizes do I mean? We could work out that information and come to the entirely accurate value for my shoe size but it would still not constitute evidence for my Joe Bloggs theory.

These prob. That we are talking about are shoe sizes. They neither confirm not refute.

- Jeff

I have a lot of time for you, Jeff. I respect your analytical abilities and your methodical approaches and ideas. I think for the crimes of JtR as a whole you offer great value. In particular, your analysis on geographical profiling was to me quite extraordinary and hugely interesting.

My issue here is thus; Ike at no stage claimed it was proof of anything. The values he cited cannot be regarded as irrelevant, but nor can the results of the calculation can be regarded as absolute evidence. It is simply very interesting. It provides an interesting starting point for further discussions and analysis. He has not claimed ANYTHING. He is merely calculating the odds of two events linked by James Maybrick as occurring on the same day. He has not made any grand declarations.

Can you not at least give him credit for being correct in principle thus far?

[JeffHamm]

Hi Jeff,

Thank you for this latest post. With a bit of luck (pardon the pun), we could be getting close to ending this discussion once and for all.

You clearly post and indeed post regularly (I've often seen your name on the sidebar), but what you may not be familiar with are the extraordinary rules which operate on this, The Greatest Thread of All, which ensure that absolutely every point made must be thrashed-out to the nth degree because nothing must be left on the table. This is Psychology 101. You must not leave any scraps on the table because we have a couple of Hungry Boys who love nothing more than minesweeping to see what's left and turning that into what they claim is a very tasty meal. By this means, they have turned obfuscation into an art form and it is done for one reason only, to put paid to any argument whatsoever which on face value seems to favour the possibility that the Victorian scrapbook is authentic. The possibility that the Victorian scrapbook is authentic is not one which The Hungry Boys will consider and they will not permit others to consider it. Thus, you say you have no dog in this race but - on this thread - you do. Because your posts - whether you have intended this or not - have carried an underlying tone of "improbable coincidences are common events", you have been leaving scrap after scrap for The Hungry Boys to feast over. There are some truly problematic issues for the street corner lads to deal with and there are two in particular which are so problematic for the hoax theory that the HBs take the extraordinary step of simply denying they exist. And, sadly, you have fuelled their efforts in respect of one of those two. For clarity, I'm talking about The Miraculous Day and the 'FM' on Mary Kelly's wall. By posting as you have, you have left little scraps (soundbites primarily) for the HBs to leap onto. One of them can't post here anymore so he has his own website which he won't be updating until September (I think) but you can rest assured that there will be servers all around the world now quaking at the thought of how many bytes he's going to consume from the scraps you've left him. So, RJ and Lord Orsam (to name them) say that the 'FM' initials are simply not there at all. They are there in every incarnation I have ever seen of the infamous photograph (including Dan Farson's splendid 1972 reproduction) but according to Lord Orsam he has seen an original and the letters are not there so the debate is over. With The Miraculous Day, the two of them have either argued that there was no coincidence or that - bizarrely - the odds of them happening by chance were as certain as 1-in-18.

So, it is left for people like me to defend the diary against obfuscation and plain mendacity. To do so, I personally have consistently noted how unlikely it was that the two events of March 9, 1992 - linked as they were rather explicitly by James Maybrick - would happen by simple chance alone. I may have gone further on occasions and implied that this was evidence that the scrapbook came out of Battlecrease House on the morning of March 9, 1992, but I'm willing to re-phrase that in future. Indeed, I'll do it right now: the fact that these two events happened on March 9, 1992, some 37,557 days after they first could have happened either separately or simultaneously is indicative of something which needed to be investigated further. For me, and for most reasonable observers with no axe to grind it was a simple 1-in-37,557 chance. As you were willing to repeat your mental experiment when you got five heads in a row - at odds by chance of just 1-in-32 - then so I feel more than justified in investigating Maybrick further because The Miraculous Day gave us odds of around 1,000 times lower than your coin tossing. The fact that you have prefaced your mental experiment with the coin by defining it as 'fair' can make no difference to us here (or anywhere else). I assume that you have analysed far more than simple coin tosses in your career? When you have, you must have known that you were analysing factors for which many unknown variables theoretically might have influenced the data you got. But you ploughed on regardless because you knew that you could never factor in every single possible variable, every butterfly fluttering its wings in India and causing Sunderland to get stuck in League One for a fourth season on the trot (long may those butterflies flutter, by the way).

So the argument is either that the odds of two events happening simultaneously can never be calculated (oh how The Hungry Boys would love you to say that) or that the odds of two events happening simultaneously can be calculated (but you have to allow for - or at least acknowledge - known and unknown variables which could affect your data). Your posts are redolent of the former and maybe that's not what you've been trying to say? Whether you have or you haven't, you have certainly left our dear readers unsure and therefore two of them in particular rubbing their hands in glee before the boiling pot.

From your latest post, you appear to be saying that you can't use the fact of the two (or more) simultaneous events as evidence in itself, and I will happily accept that point. But no-one - certainly not I - would have even noticed the miracle of March 9, 1992 if it were not so profoundly unlikely to have happened by chance alone. My 1-in-37,557 probability (as I have said on countless occasions) is a simple, straightforward odds calculation based on the three things we know (which I won't repeat).

In conclusion, I think you have contested my implied (or indeed actual - I honestly don't recall) use of The Miraculous Day as evidence for the authenticity of the diary, and I think you have made your point; but that was not what was being asked - what was being asked was what were the odds of The Miraculous Day happening in the first place. You have intimated that those odds cannot be accurately calculated, or else cannot be calculated at all, and that is what RJ and LO wanted to hear. Personally, I think - if that's what you meant to say - you are wrong and I have to keep saying it otherwise my silence will be construed as defeatism: the simple odds were 1-in-37,557 (and if we were God and knew the impact of all known and unknown variables our 37,557 might be a bit smaller but - honestly - surely not in any meaningful way that the baby needed to be thrown out with the bath water?).

By the way, Jeff, if you had not intended to appear to have a dog in the race, why did you contest so persistently my 1-in-37,557 odds for The Miraculous Day, but say nothing in regards to Lord Orsam's Comic Cuts 1-in-18 odds? By doing so, I infer that you do have a dog in the race, you just haven’t realised it. Just letting you know, mate.

Ike

Hi Ike,

I've used your 1/37000+ because the discussion has primarily been between you and I, but I've also made it clear it doesn't matter what value one argues for;. No matter what value one argues for is still to argue for an irrelevant value. These probabilities, whether high or low contribute nothing to the evaluation of the hypothesis. It's like me saying Joe Bloggs was JtR and my evidence is my shoe size is 10.5, and we debate what system if shoe sizes do I mean? We could work out that information and come to the entirely accurate value for my shoe size but it would still not constitute evidence for my Joe Bloggs theory.

These prob. That we are talking about are shoe sizes. They neither confirm not refute.

- Jeff

[Iconoclast]

Ultimately, if you want to prove the statisticians and logicians and skeptics wrong, you’re going to have to supply evidence rather than Ike’s circular sophistry.

That should be the end of it.

RP

Happy for this to be the end of it (for now). Our dear readers need to decide for themselves how comfortable they are about The Miraculous Day. If they feel that the floorboards coming-up and the call to the literary agent from a guy in Liverpool who drank in the same pub as a member of the P&R team (despite Battlecrease being eight miles away) for the very first time on the record 37,557 days after Maybrick died is just one of those things that happen all the time then that is their decision to make.

The odds of that happening by chance alone were 1-in-37,557 in terms of simple probability theory. If people wish to factor in the increased aging of the house as a reason to reduce the odds then they are welcome to do so (I'm not sure how that would be done with any accuracy, however). The odds which remained would still set off alarms bells in an open mind and give one cause to investigate further (cf. Jeff Hamm).

Ike

[rjpalmer]

I'm not sure, Caz, but I think my initial 1-in-26,000 (excluding Sundays and Bank Holidays?) may have come before his 1-in-18. Interestingly, I think he first came up with it in response to Robert Smith's 25 Years publication rather than, say, my brilliant Society's Pillar so who knows?

Ike

Thanks, Ike.

But it won't matter. It will still be Orsam's fault, and people will still believe that Dodd having work done on his house on any random day must be tens of thousands to one.

[rjpalmer]

If Jeff is saying any such calculation is bogus, then I hope for RJ's sake that I am misremembering, and it wasn't Orsam who started it.

Love,

Caz
X

This is Classic Caz, and on so many levels.

“If Jeff is saying that any such calculation is bogus” (yes, Caz, he IS saying that, and it’s the same thing I’ve been pointing out for two weeks!) then it is somehow someone else’s fault—mine, Lord Orsam’s, Jeff’s, anyone’s—but certainly not your own, and certainly not Ike’s.

You wouldn’t be looking so silly right now, Caz, had you simply taken Scott’s advice and steered clear of Ike’s bogus statistical analysis.

Instead, you jumped in feet first and even suggested (as did ‘Erobitha’) that those who couldn’t comprehend Ike’s foolproof methods (me, to be specific), simply lacked the “critical thinking skills” to understand their legitimacy. I think a drunken baker was even mentioned.

Those insults didn’t age too well, did they?

As Ike admits (sort of; elsewhere he misstates them), ‘David Orsam’ wasn’t the one who launched into this foolishness, he was merely responding to Ike’s earlier and entirely different calculation—26,000 to 1. (How many different calculations does that make, Ike?)

Nor was Orsam saying the odds of the double-event were 18 to 1. He was simply pointing out (as Jeff has pointed out in different ways) that it isn’t all that unusual to have someone work on your house. Dodd had people in 14 different times in 1992, so it would be 18 to 1 that this would coincide with any random workday of that year---a day when someone could call an agent. (We can’t count weekdays and holidays since a Literary Agency would be shut down on those days).

As I stated in Post #6558, all such odds are ultimately meaningless, but Orsam’s example served as a necessary correction to Ike’s chicanery. I think I'm repeating myself, but if Ike had wanted to attempt a more rational rebuttal to Orsam, he could have pointed out that the year 1992 was not a usual one for Dodd; his house had undergone a major renovation. We don’t know the numbers, but using a 10-year average, maybe the odds would have been greater---36 to one, or 72 to 1, or even higher. Who knows?

But what is most amusing are the two things you are studiously attempting to avoid by shifting the conversation to Orsam, who is not even allowed a rebuttal.

First, you’re fulfilling my prediction from two weeks ago that you will never admit in plain English that Ike’s statistical analysis is bogus. You will continue to dance around it, because Ike is telling you precisely what you want to hear, and what you want people to believe.

Second, you won’t acknowledge that Osam was actually being generous! He was only limiting himself to Battlecrease, and only using the example of Dodd having electricians in. The diarist doesn’t say diddly about leaving his confession at Battlecrease, let alone under the floorboards. An unconfirmed provenance ‘story’ could have developed from other events—guests staying in the house, a garage sale held in Aigburth, an exterminator digging around in the attic, John Over’s outhouse, etc. As Jeff points out, Ike is using using circular reasoning--without even knowing it.

Thus, as disgusted as you are by these 18 to 1 odds, Jeff himself has estimated the odds of a provenance story developing at approximately 1:1.

100% of the time!!

This is valid, because that’s what we humans do. We create stories. We connect events that are unconnected.

On that note, can we get back to reality now, instead of trying to score ‘political’ points?

Feldman believed the ‘double event’ could be explained by humans being humans. Dodd simply had word done on his house. Nothing unusual in that. Someone asked him about it, and then asked the electrical company, who denied anything being found. But Feldman—a film producer—made more inquiries and someone started repeating ‘stories.’

Feldman, being a businessman and someone astute about such matters, ultimately felt the lure of money or 15 minutes of fame had encouraged someone to make up a provenance story. (The same thing Orsam is suggesting, if I read him right). The electrical work was real—no debate there—but the story of something having been found has never been confirmed and remains unreal without evidence.

It’s not ‘cricket’ to ignore the need for evidence, and to instead insinuate that the 'connection' IS real, by quoting bogus statistics or flawed logic.

Isn't that the lesson we have learned here?

Ultimately, if you want to prove the statisticians and logicians and skeptics wrong, you’re going to have to supply evidence rather than Ike’s circular sophistry.

That should be the end of it.

RP

[Iconoclast]

Morning Ike,

I am probably misremembering this, but wasn't the first calculation the one undertaken by Orsam, who has the biggest, snarliest dog in the race? And wasn't it designed to counter the suggestion that if the 9th March 1992 double event was a coincidence, it was a pretty staggering one?

Orsam didn't start from a neutral position, and his motivation was always to diminish the scale of the coincidence as far as he thought he could get away with, by arbitrarily omitting any dates prior to 1992 [his 1 in 18] and, if that failed to keep the opposition party quiet, his fallback position was to reconnect the two single events, so there would be no coincidence after all, but only in ways that would keep his dream alive that Mike faked the diary with Anne over 11 days between 1st and 13th April 1992.

If Jeff is saying any such calculation is bogus, then I hope for RJ's sake that I am misremembering, and it wasn't Orsam who started it.

Love,

Caz
X

I'm not sure, Caz, but I think my initial 1-in-26,000 (excluding Sundays and Bank Holidays?) may have come before his 1-in-18. Interestingly, I think he first came up with it in response to Robert Smith's 25 Years publication rather than, say, my brilliant Society's Pillar so who knows?

Ike

[Iconoclast]

What if the two people both had the same name: Theophilus P Wildebeest?

I had a colleague who was born on the same day as me which was a bit weird. Amazingly enough, we both had one child, and they too were born on the same day. Na noo na noo?

Well, not exactly. Because hundreds of thousands of people are being born each day (207,000 have been born today already, 1pm UK time), it is inevitable that we share our date of birth with hundreds of thousands of people amongst whom it is extremely likely that at least one other would have their only child on the same day we did. So sounds staggeringly unlikely, but is probably very common.

What was staggeringly unlikely, however, was that she and I would 1) ever meet, and 2) uncover that seemingly-outlandish stat. Perspective is everything, it would appear.

Whatever happened to Sir Lenny, by the way?

Ike

[caz]

Okay, I thought I was on safe ground with the cinema example as I assumed you'd take the point but you didn't. I clearly wasn't on safe ground with the floorboards example, and I clearly wasn't with the cinema example so let's try shifting our example more towards the logical extremes - you know, the absurd cases which finally make the point (or lose it).

If we know that two people wrote their names on a separate piece of paper on one day only during the same seven day period, what are the chances that they wrote their names on those pieces of paper on the same day by chance alone? Surely this time we can agree it's a 1-in-7 probability that they did so on the same day by chance alone?

No, hold on, we might get into arguments about whether they both had paper or not or whether they were using pens or pencils, et cetera, so let's exclude as many variables as we can. Let's say they only spelled their names in the air once during the same seven day period. Surely this time we can agree it's 1-in-7?

And - before you raise it - yes, they both had at least one finger. If that's an assumption too many then I am going to hypothesise that we need to call this a day ...

PS There was a quicker way for me to try to make my point, I think: In your world, Jeff, is there any simple scenario at all where the probability is known and calculable or does the influence of known and unknown variables always mean that probability is actually Schrodinger's latest cat???

Ike

What if the two people both had the same name: Theophilus P Wildebeest?

[caz]

Morning Ike,

I am probably misremembering this, but wasn't the first calculation the one undertaken by Orsam, who has the biggest, snarliest dog in the race? And wasn't it designed to counter the suggestion that if the 9th March 1992 double event was a coincidence, it was a pretty staggering one?

Orsam didn't start from a neutral position, and his motivation was always to diminish the scale of the coincidence as far as he thought he could get away with, by arbitrarily omitting any dates prior to 1992 [his 1 in 18] and, if that failed to keep the opposition party quiet, his fallback position was to reconnect the two single events, so there would be no coincidence after all, but only in ways that would keep his dream alive that Mike faked the diary with Anne over 11 days between 1st and 13th April 1992.

If Jeff is saying any such calculation is bogus, then I hope for RJ's sake that I am misremembering, and it wasn't Orsam who started it.

Love,

Caz
X

[Iconoclast]

Hi Jeff,

Thank you for this latest post. With a bit of luck (pardon the pun), we could be getting close to ending this discussion once and for all.

You clearly post and indeed post regularly (I've often seen your name on the sidebar), but what you may not be familiar with are the extraordinary rules which operate on this, The Greatest Thread of All, which ensure that absolutely every point made must be thrashed-out to the nth degree because nothing must be left on the table. This is Psychology 101. You must not leave any scraps on the table because we have a couple of Hungry Boys who love nothing more than minesweeping to see what's left and turning that into what they claim is a very tasty meal. By this means, they have turned obfuscation into an art form and it is done for one reason only, to put paid to any argument whatsoever which on face value seems to favour the possibility that the Victorian scrapbook is authentic. The possibility that the Victorian scrapbook is authentic is not one which The Hungry Boys will consider and they will not permit others to consider it. Thus, you say you have no dog in this race but - on this thread - you do. Because your posts - whether you have intended this or not - have carried an underlying tone of "improbable coincidences are common events", you have been leaving scrap after scrap for The Hungry Boys to feast over. There are some truly problematic issues for the street corner lads to deal with and there are two in particular which are so problematic for the hoax theory that the HBs take the extraordinary step of simply denying they exist. And, sadly, you have fuelled their efforts in respect of one of those two. For clarity, I'm talking about The Miraculous Day and the 'FM' on Mary Kelly's wall. By posting as you have, you have left little scraps (soundbites primarily) for the HBs to leap onto. One of them can't post here anymore so he has his own website which he won't be updating until September (I think) but you can rest assured that there will be servers all around the world now quaking at the thought of how many bytes he's going to consume from the scraps you've left him. So, RJ and Lord Orsam (to name them) say that the 'FM' initials are simply not there at all. They are there in every incarnation I have ever seen of the infamous photograph (including Dan Farson's splendid 1972 reproduction) but according to Lord Orsam he has seen an original and the letters are not there so the debate is over. With The Miraculous Day, the two of them have either argued that there was no coincidence or that - bizarrely - the odds of them happening by chance were as certain as 1-in-18.

So, it is left for people like me to defend the diary against obfuscation and plain mendacity. To do so, I personally have consistently noted how unlikely it was that the two events of March 9, 1992 - linked as they were rather explicitly by James Maybrick - would happen by simple chance alone. I may have gone further on occasions and implied that this was evidence that the scrapbook came out of Battlecrease House on the morning of March 9, 1992, but I'm willing to re-phrase that in future. Indeed, I'll do it right now: the fact that these two events happened on March 9, 1992, some 37,557 days after they first could have happened either separately or simultaneously is indicative of something which needed to be investigated further. For me, and for most reasonable observers with no axe to grind it was a simple 1-in-37,557 chance. As you were willing to repeat your mental experiment when you got five heads in a row - at odds by chance of just 1-in-32 - then so I feel more than justified in investigating Maybrick further because The Miraculous Day gave us odds of around 1,000 times lower than your coin tossing. The fact that you have prefaced your mental experiment with the coin by defining it as 'fair' can make no difference to us here (or anywhere else). I assume that you have analysed far more than simple coin tosses in your career? When you have, you must have known that you were analysing factors for which many unknown variables theoretically might have influenced the data you got. But you ploughed on regardless because you knew that you could never factor in every single possible variable, every butterfly fluttering its wings in India and causing Sunderland to get stuck in League One for a fourth season on the trot (long may those butterflies flutter, by the way).

So the argument is either that the odds of two events happening simultaneously can never be calculated (oh how The Hungry Boys would love you to say that) or that the odds of two events happening simultaneously can be calculated (but you have to allow for - or at least acknowledge - known and unknown variables which could affect your data). Your posts are redolent of the former and maybe that's not what you've been trying to say? Whether you have or you haven't, you have certainly left our dear readers unsure and therefore two of them in particular rubbing their hands in glee before the boiling pot.

From your latest post, you appear to be saying that you can't use the fact of the two (or more) simultaneous events as evidence in itself, and I will happily accept that point. But no-one - certainly not I - would have even noticed the miracle of March 9, 1992 if it were not so profoundly unlikely to have happened by chance alone. My 1-in-37,557 probability (as I have said on countless occasions) is a simple, straightforward odds calculation based on the three things we know (which I won't repeat).

In conclusion, I think you have contested my implied (or indeed actual - I honestly don't recall) use of The Miraculous Day as evidence for the authenticity of the diary, and I think you have made your point; but that was not what was being asked - what was being asked was what were the odds of The Miraculous Day happening in the first place. You have intimated that those odds cannot be accurately calculated, or else cannot be calculated at all, and that is what RJ and LO wanted to hear. Personally, I think - if that's what you meant to say - you are wrong and I have to keep saying it otherwise my silence will be construed as defeatism: the simple odds were 1-in-37,557 (and if we were God and knew the impact of all known and unknown variables our 37,557 might be a bit smaller but - honestly - surely not in any meaningful way that the baby needed to be thrown out with the bath water?).

By the way, Jeff, if you had not intended to appear to have a dog in the race, why did you contest so persistently my 1-in-37,557 odds for The Miraculous Day, but say nothing in regards to Lord Orsam's Comic Cuts 1-in-18 odds? By doing so, I infer that you do have a dog in the race, you just haven’t realised it. Just letting you know, mate.

Ike

[JeffHamm]

Okay, I thought I was on safe ground with the cinema example as I assumed you'd take the point but you didn't. I clearly wasn't on safe ground with the floorboards example, and I clearly wasn't with the cinema example so let's try shifting our example more towards the logical extremes - you know, the absurd cases which finally make the point (or lose it).

If we know that two people wrote their names on a separate piece of paper on one day only during the same seven day period, what are the chances that they wrote their names on those pieces of paper on the same day by chance alone? Surely this time we can agree it's a 1-in-7 probability that they did so on the same day by chance alone?

No, hold on, we might get into arguments about whether they both had paper or not or whether they were using pens or pencils, et cetera, so let's exclude as many variables as we can. Let's say they only spelled their names in the air once during the same seven day period. Surely this time we can agree it's 1-in-7?

And - before you raise it - yes, they both had at least one finger. If that's an assumption too many then I am going to hypothesise that we need to call this a day ...

PS There was a quicker way for me to try to make my point, I think: In your world, Jeff, is there any simple scenario at all where the probability is known and calculable or does the influence of known and unknown variables always mean that probability is actually Schrodinger's latest cat???

Ike

Hi Ike,

No, I got what you were getting at but just was pointing out the probability of things in real life are rarely as simple as that. But the main point is that you're still focusing on probabilities that do not matter with regards to the question of whether or not there's a connection between the floorboards and the phone call. At some points you say you're not making that claim, but as I've indicated, you continually are making statements that show otherwise. It's those statements that I'm focused upon because those are where the important error is, the quibbles about whether or not to divide the repair probabilities as a flat or increasing distribution is not really important, it's whether or not those probabilities are at all informative with regards to the diary/floorboards/phone call connection.

Now, you asked if there's a simple scenario where we can calculate probabilities, etc. Of course there is, we can simply set up such a safe example, which you did before, flipping a fair coin. This is why coin flips, or die rolls, are often used in statistics lectures. They are nice, closed, simple situations. And, we also define out any annoying real world complications (like edge landing, etc) and talk about our theoretical "fair coins". We define it out of reality to get at the underlying notion of probability theory.

So, if I flip a fair coin, it has by definition a 50% chance for heads and 50% chance for tails.

If I flip a coin 5 times, and get all heads, I have 1/2^5 probability of getting that, or 3.125% chance probability for a fair coin.

So, if I saw that outcome, I might then question if indeed my coin is fair, I might start to think it is biased. So I flip it again, and get a head.

Have I tested the coin's fairness? Do I calculate that 2^6 = 1.5625% and present that as evidence my coin is biased?

If you said yes, you've got that answer wrong on the exam.


See, once I had my 5 heads a fair coin gives me a 50% chance of getting a head on that critical test throw. And, I only flipped it a sixth time because I happened to observe the first 5 heads. Without them, I wouldn't have thought my coin biased. It was that observation, which is admittedly rare, that made me formulate a hypothesis about bias in the first place. Without those known events, the hypothesis would not exist because it is a post-hoc one offered only as a possible explanation for what I have observed. The question itself might be a rare event!

That means I can't use those 5 flips as part of the test because they are the observations that made me formulate the hypothesis; my hypothesis only exists because of those known events (I know I'm being repetitive, but this is what I was getting at earlier when I was mentioning things like how known events complicate matters, and counter-intuitive - we want to use those 5 flips as evidence, it feels like we should, common sense tells us we should - , and so forth, and all those things telling us to use them are wrong).

See the past 5 heads happened, and while they might be rare for a fair coin they can still happen. I'm only considering the hypothesis that the coin is biased because it's been observed, the question itself only exists as a result of those known events. But hypotheses create predictions for future events that I do not yet know, and those I can test to see if they also happen. I now have to collect new evidence to test my hypothesis, which may only exist by chance, and one single flip has a 50% chance of being heads if my coin is fair. So no, my "6th flip" is not enough, so I do 5 more flips and if in those next 5 flips I get 3 tails and 2 heads, I'm probably going to realize my coin was fair all along and that unlikely observation that made me question it's fairness in the first place was just one of the rare events that can happen. But if my hypothesis were correct, then my next pattern of flips will also produce evidence that is unlikely for a fair coin to produce (because my hypothesis is that the coin is biased to come up heads and if that is true, I will continue to get more heads than tails).

That's a simple example that parallels exactly what we're dealing with. An observation has been made, the two events (our 5 heads). We formulated a hypothesis involving a connection between them (biased coin, common event), with the boring alternative that they co-occurred by chance (fair coin, rare event). Without those two events being already known (floorboards & phone call) though, we would not have formed the hypothesis that the diary was under the floorboards, etc. We aren't talking about the diary coming from amid the plumbing, for example, because we hadn't observed that plumbing work was done at Battlecrease. There are lots of other hypotheses that do not "exist" in the discussion, what we want to know is whether or not this one "exists" simply because it was the particular rare event that happened (i.e. it is just as unlikely to get HTHTH, as HHHHH; but some pattern has to arise, and each one is just as rare as the others).

We do not, and cannot, use the initial probability of the specific events to test the hypothesis because we only have the hypothesis because they are known events - they are the question, they are not the answer. You're trying to rephrase the question in the form of an answer when you reuse them but this is not reverse Jeopardy.

Note, as I say, I'm offering no opinion on the diary itself, I'm only getting at the use of the probabilities being discussed here, and the ones being discussed are irrelevant with regards to whether or not the diary came from under the floorboards. They are known events, they are what created the hypothesis, they are not involved in the answer to the question they create.

- Jeff