Talk:Mathematics of bookmaking

Mathematics of making a book (betting)
If the term 'bookmaker' is considered notable then I am of the opinion that the main mathematical means by which a bookmaker makes his living is also notable. It is no different from mathematical aspects of any financial transaction, many of which are described within Wikipedia's pages. I am as yet unable to find any website that fully explains the process I am describing; I believe this is because they are mostly sites that exist for purely financial reasons (selling books, betting systems etc.) rather than as points of reference. Thus as an encyclopedia and place for reference I feel my article deserves inclusion. If no definitive article can be found on the internet then surely such an article on Wikipedia fills this important gap? AirdishStraus 19:03, 13 October 2007 (UTC)
 * It's entirely possible that the subject is notable, but the tag indicates that the article doesn't demonstrate notability via the use of appropriate footnotes and references. Please don't remove the tag without fixing the article and demonstrating the notability of the subject. Rray 22:28, 13 October 2007 (UTC)
 * Article has the problem of overcoming no original research. I take it as read that because bookmaker is already an article, notability for that has been established. To take it a step further needs to look at risk management, statistics etc. To synthesize these into this article without external references may be tricky, but not impossible. I'd find it hard to believe that no academic has ever examined this. -- Rodhullandemu  (talk - contribs) 23:02, 13 October 2007 (UTC)
 * "I am as yet unable to find any website that fully explains the process I am describing", then this appears to be original research and needs to be deleted as such. that may not make sense to a lot of people, but it is the clear policy of the encyclopeia to not publish original research.  Then perhaps more to the point, a brief explaination on the bookmaker article may be a better location.  Mathematics of bookmaking sounds pithier to me too. 2005 23:14, 13 October 2007 (UTC)
 * Agreed. "Mathematics of bookmaking" is a far better title for this article. Does anyone have any objections to changing the title of the article? Rray 01:52, 14 October 2007 (UTC)
 * Eventually found your comment. New heading would have helped. That aside, yes. Please move it to an appropriate title. Details can be sorted later. -- Rodhullandemu  (talk - contribs) 01:56, 14 October 2007 (UTC)
 * Heh. Eventually? I just made the comment about 5 minutes ago, maybe 10. I'll change the title in a bit. Thanks for your input. :) Rray 02:07, 14 October 2007 (UTC)
 * It doesn't have to be a website, although that makes things a whole lot easier. There is a whole lot of mathematical/statistical stuff out there about decision-making processes, bookmaking being a small corner of this. Whether it deserves an article of its own remains undecided until any research can be found and cited. As a gut feeling, I don't think bookmakers, say, on a racecourse, consciously apply mathematical rules, because they seem to operate instinctively, based on experience. The corporates (such as Ladbroke's, William Hill etc) are more sophisticated and almost certainly employ statisticians. I'd be interested, however, to see if any research has been done. If so, then that, referenced, would certainly support this article. -- Rodhullandemu  (talk - contribs) 23:32, 13 October 2007 (UTC)
 * Additional :: Nobody is going to come to WP and search for this title, so it has to be linked from elsewhere within WP. There are several candidates for this. If I can think of a pithier title which may make the article more accessible "up front", I'll move it, if that's OK. -- Rodhullandemu  (talk - contribs) 23:37, 13 October 2007 (UTC)

Comments as result of comments (meta-comments?)
Looking at it, it's messy. Jargonised, unstructured and impenetrable to a layman. My philosophy is that as long as notability is established, an article should inform a newcomer such that they leave better informed than when they arrived. I'll put this on my "to-do" list to try and polish it into a readable article. -- Rodhullandemu  (talk - contribs) 22:51, 13 October 2007 (UTC)


 * "Impenetrable"?? You've got to be kidding.  Certainly the article could be greatly improved, but certainly anyone who's graduated from high school would understand what it now says. Michael Hardy 00:17, 14 October 2007 (UTC)
 * ...and frankly, I'd rather see it also contain some material that I would consider impenetrable to those who don't like math. Michael Hardy 00:18, 14 October 2007 (UTC)
 * I can appreciate your preference here, but an encyclopedia is not the place for information that's impenetrable. The whole point of an encyclopedia is to explain factual information in a way that a laymen can gain an understanding of it. Thanks for including 2 references, but are those actual sources for the specific statements in the article? The article needs footnotes and citations, not just a list of "references" that are about the same subject but didn't actually comprise the content here. Rray 01:55, 14 October 2007 (UTC)


 * I didn't say we should have impenetrable things here; I said we should have things that people who don't like math would call impenetrable. We can't exclude, and haven't excluded, mathematics from Wikipedia.  But some people insist on exclaiming about the impenetrability of all mathematics.  Only those people would find what's here now to be impenetrable.  And if someone's going to behave like that, they shouldn't hold the rest of us back. Michael Hardy 03:45, 14 October 2007 (UTC)
 * ...for example, how about homotopy groups of spheres? Impenetrable?  Some people want to make it a Featured Article.  I just might back that effort. Michael Hardy 03:46, 14 October 2007 (UTC)

<---outdent & rebegin I don't remember how I came to this article. But when I did, I found it as a layman, impenetrable. OK, it's unlikely, as I've already pointed out, that someone would stumble across it. But, looking ahead, when it's finished, and linked from appropriate articles, it should expand and explain, clearly and concisely, what it's about. See my initial comment above. And there's no need for it to be overly mathematical, we would not be dealing with the outer limits of math. If math has to be in, then high school math should be accessible. As I said, I have put it on my to-do list. Don't be chagrined by that; if ever you've seen a WP article that could not be improved, I'll give you $1m. -- Rodhullandemu  (talk - contribs) 00:44, 14 October 2007 (UTC)

Comments from the original author
Nice to see a friendly [sic] 4-way discussion over the - as yet incomplete - article 'wot I wrote'. Let's clear up a few points shall we? I WAS a bookmaker and know the topic of the article (AS IT RELATES PRIMARILY TO UK HORSERACING AND FIXED ODDS BETTING) inside out. I AM a maths/stats teacher/lecturer and as such have pitched the maths such that a smart 16-18 year old maths student could quite easily comprehend it. I know this because I have actually taught this maths to students in a non-classroom situation (awareness of being 'fleeced' by bookmakers is an important piece of knowledge to have as an as yet unworldly-wise teeenager - I remember my own past!). The maths contained thus far in the article (there will be more) can hardly be made more simple whilst remaining in a realistic context - I have chose basic premises for the explaining of the basic principles involved.

This article is NOT original research. It therefore deserves to be here on WP because it explains the concept of 'making a book' using decades-old (if not centuries-old) principles of the art of bookmaking. The fact that no-one has bothered to put this maths elsewhere on the web is probably because no-one as yet could be arsed to. The web is mainly money driven: why have stuff out there that has probably cost you money in hosting fees (unless you have free access to upload what ever you want to) if it produces no financial return. We write articles for WP on philanthropic principles, to benefit those who choose to read them. These articles give one the opportunity to better understand a particular topic; it doesn't necessarily guarantee that you will come away from the article with a perfect knowledge of what you have read. Those with a mathematical 'blind spot' won't be able to understand the maths no matter what level it is pitched at. Does this mean that the article should not be written? Or that the maths be 'dumbed-down' beyond belief? Of course not. We write articles to better inform those who are able and willing to be better informed.

Mathematics of bookmaking may be a better title for the article. I may move it myself, and have the original title (or version of) as a section heading. I would like to maintain a distinct separation between the traditional book made on horseracing and fixed-odds football matches and other types of betting on sports and 'American-parlance' betting concepts.

While we're at it, rather than you chance upon any comment I may put on the discussion page for Vigorish I would be interested in your thoughts on a comment in the early part of the article which mentions overround... I am of the opinion that if vigorish is defined as a payment to a bookmaker for his services, then overround is defined as the theoretical maximum profit built in to a book by the adjustment of the odds. I believe these two terms are inherently different from each other. I plan to develop the overround concept with THIS current article as it is pertinent to the bonuses that bookmakers pay on successful multiple bets e.g. Lucky 31, all four correct in a Yankee et al. AirdishStraus 12:12, 14 October 2007 (UTC)

Notability tag
I've removing the tag questioning notability of the the article subject. A quick search on Google Scholar for bookmaker odds reveals 747 hits. I can remember reading a few years ago an academic article on how the Australian TAB set its odds. There is extensive academic literature on this subject, and particularly on the market efficiency of bookmaker odds. Even on the narrowest, most mean spirited test it therefore satisfies WP:NOTABILITY. The terminology being explained here is industry-standard, in no way neologistic. This is absolutely a proper and appropriate subject for a WP article. Jheald 16:21, 15 October 2007 (UTC)
 * Many thanks! (The author) AirdishStraus 17:02, 15 October 2007 (UTC)
 * The subject of this article isn't "bookmaker odds", and I don't think the phrase "bookmaker odds" is synonymous with "mathematics of gambling" necessarily, either. Perhaps merging this article into an article on "bookmaker odds" might make more sense. But even if you do so, notability is supposed to be established in the article via the use of footnotes. I'm not interested in an edit war, but removing the tag without demonstrating notability in the article is inappropriate. Rray 17:45, 15 October 2007 (UTC)
 * Mmmm... The 'Odds' page on WP unfortunately has a mix of info on 'scientific odds' and 'bookmaking odds'. I can re-write the page to separate the two under different section headings for clarity. However, the mathematics of bookmaking (as it applies in the UK to horse racing and fixed odds betting - primarily football, but other sports as well) is definitely a stand-alone topic in its own right and as someone has already mentioned is entirely notable just for its mathematics content, yet alone anything else that the page contains. The article that I am writing - 'Mathematics of bookmaking' - is specific content that forms just part of the topic of Mathematics of gambling. The Mathematics of Spread Betting would also, in my opinion, be able to satisfy notability simply because of its maths content. I am not writing it though, as I am not an expert - I was a traditional 'Odds' bookie. Then there is the maths involved in casino games e.g. roulette. If we are trying to produce a definitive Wiki Gambling project then ALL relevant info should be included. It would be too much to include all these aspects on one page; they deserve separate pages as they have different aspects of mathematics. AirdishStraus 18:53, 15 October 2007 (UTC)
 * Notability isn't demonstrated by opinions on talk pages; it's demonstrated by footnotes to reliable sources in the article itself. That's the point I was trying to make, but I should have been more concise. :) Rray 19:13, 15 October 2007 (UTC)


 * Well obviously removing the tag from a mathematics of bookmaking article because a search for bookmaker odds returns results makes no sense at all. Searches for mathematics of making a book and mathematics of bookmaking turn up zero and six results.  Absent sources this article is close to an afd as original research. 2005 21:55, 15 October 2007 (UTC)

I think "methods of making a book" or "methods of bookmakers" or "methods of bookmaking" is a far better title. It's clear from my cursory investigation that there is more than mathematics, strictly speaking at play. Economics, a bookmaker's penchant for risk, etc., all play a role. For example, bookmaking firms laying the first odds will try for much higher margin because of the greater risk. As for notability, there are books and plenty of articles. The content itself may be OR (I don't know if it is, haven't look at it thoroughly) but that is beside the point. Even crappy articles (which I'm not saying this one is) are not deleted if the topic is notable. --Horoball 12:50, 23 October 2007 (UTC)


 * Thanks for your comments. As the author of the article I must emphasise that this article is (when eventually completed) solely about the mathematics of bookmaking. I appreciate that the whole topic of bookmaking encompasses economics, psychology and possibly any number of other areas, but I feel they would more appropriately be located in the article Bookmaker. Due to the lack of any other suitable article about this topic on the web then as an expert in the field I virtually felt obliged to write one: if articles like this were available in 1982 when I first ventured into bookmaking I am sure I would have been better informed and learnt my trade a lot quicker and more easily! I guess I'm trying for a notable article that will inform those interested in the general field of gambling but more specifically those who have a real desire to comprehend the essential (and industry standard) mathematics behind bookmaking: obviously benefiting those who might want to actually be a bookmaker, or more likely those who are serious about 'knowing the maths' so that they can try and 'beat the bookie'. Feel free to post more comments and/or suggestions as to what you might like to see in any of the Gambling articles on WP. I would welcome feedback. AirdishStraus 13:20, 23 October 2007 (UTC)


 * I've been away a while. It seems we are no longer concerned with notability, but original research. I have somewhere a copy of "Lady Luck" by Warren Weaver which, although a moderately scholarly work on probability theory, does include a chapter on betting (15, IIRC). It's an old book now but still regarded as useful even though the maths pre-dates pocket calculators! Citing works such as that for some of the propositions in the article would get over the OR problem. However, refs would still be needed for some of the "industry" terms. -- Rodhullandemu  (talk - contribs) 13:36, 23 October 2007 (UTC)


 * Welcome back. Parole? Just a joke! No pressure, but if you could match a small bit of the content to that in Chapter 15 of your book and either Note or Reference it at the foot of the page I would be extremely grateful. I know the content 'inside out' but am struggling for references etc. I'm sure you understand... passion and knowledge about the topic but struggling to back it up! Thanks for the comment. AirdishStraus 13:55, 23 October 2007 (UTC)


 * It's pretty clear the article needs to be deleted pretty soon if references are not added. The further reading section is a joke at this point as it seems about everything except the topic.  This isn't a mathematics of betting article.  It's focused on the math aspect of making book.  Notability was questioned because there were no references, as it should have been.  The article's original author has even stated "Due to the lack of any other suitable article about this topic on the web then as an expert in the field I virtually felt obliged to write one" which should get it deleted right there.  We are not here to make articles on topics not covered elsewhere.  Given that admission, the article needs to be deleted or cited.  That is the policy, no original research.  It may or may not be a good policy, but this is exactly the sort of reason this policy exists. 2005 21:36, 23 October 2007 (UTC)
 * I agree that the article still hasn't demonstrated notability, and I was disappointed to see the tags removed today. I replaced those tags with a more suitable tag, and I would probably support an AfD if no one can add actual references and citations. (I'm generally an inclusionist, but this article really seems to cross the line into original research in a big way.) Rray 04:46, 24 October 2007 (UTC)
 * The original research tag was again bizarrely removed, so I added it back. It appears no online references exist, so afd seems the only choice. 2005 07:29, 24 October 2007 (UTC)
 * <-- outdent --

Why do online sources have to be the only sources? Surely it makes sense for properly researched academic works, if they exist, to be citable. I've advised the editor how to use book citations with ISBNs here. All that then needs to be done is to reference propositions in the article to those works. I don't have any of those books myself and I suspect none of them will be available online. That should not rule them out as sources. If you have to go to an actual library rather than sit at home in front of a screen, fine. There is nothing in Verifiability to imply that sources should be easily verifiable. Having said that, this work does need to be done. -- Rodhullandemu  (talk - contribs) 13:11, 24 October 2007 (UTC)
 * My thoughts exactly! I have found the ISBN of one book and am searching for the others. As soon as I have the books in my possession I will add page refs where appropriate. This is still a work in progress - maybe I should have written the whole thing on my user page or sandbox first before leaving myself open to certain editors almost demanding an AfD only 3 weeks after starting the article. I am a novice. I am willing to learn. However, after completing the two articles I am writing about betting matters I may not bother contributing ever again. Another editor did me a great help in adding further reading material; the majority of which I was not aware of. One editor seems intent on religiously following procedure and cutting the article short before I can make it acceptable under WP policy. Thanks for your comments. AirdishStraus 13:31, 24 October 2007 (UTC)
 * "Why do online sources have to be the only sources?" Umm, they don't.  So why bring it up?  Specific book page references for the statements is acceptable, although the lack of any online references obviously calls the article into question.  the problem here is we have clear original research with some general "references" are just tacked on.  For the gazillionth time, the article just needs to be cited.  This continues to be true especially since the original author admits it is his original research.  The article needs direct citations that others have written specifically about this subject in a notable way. 2005 22:35, 24 October 2007 (UTC)
 * Perhaps I misinterpreted when you said "It appears no online references exist, so afd seems the only choice", as if this was a straight dichotomy. I'm hopeful that comments to the author will result in a worthy article but I am not an expert in this field and have enough to do elsewhere. If you feel it has to be AfD'd, fine. The author needs to apply some input, however, to avoid that. -- Rodhullandemu  (talk - contribs) 22:42, 24 October 2007 (UTC)
 * No online references speaks to notability, and also to the original research issue. Book references are fine in articles, but obviously when zero references are available online for the entire topic then just listing some generally related math/gambling book titles as "references" when we no in fact they were not references, but rather the original author just wrote it, that isn't close to okay.  Absent any online references, then specific inline references from a reliable source book could meet the bare minimum here, but we'll have to see that if citiations actually do get added.  If that never happens, the thing needs an afd basically by definition.  2005 22:55, 24 October 2007 (UTC)

About percentage, or does 25% equal 1/4 or 100/4?
The meaning of an expression such as n% is n hundredths, or n/100. So, if we want to rewrite it in another way, it has to be another number or expression equalling n/100. So, for instance, 25% equals 25/100, or 1/4, not 100/4. Somebody claiming to be the "author" of this article, seems to differ, and I'd be glad to learn his or her definition of a percentage (I do not know whether or not s/he actually contributed more or less to this article: in any case, there is not such a thing as an "author" of a Wikipedia article). Happy editing, Goochelaar  (talk) 21:37, 16 May 2010 (UTC)
 * Mathematicians usually respect each others work and viewpoints (notable exception Newton and Leibnitz). You seem hell bent on proving a point that does not need to be proven. Any 12-year-old school pupil knows that a percentage may be REPRESENTED by a decimal, and vice-versa. Thus, odds of 2.3611-1 are shown as a percentage by calculating 1/(1 + 2.3611) to give a decimal answer of 0.29752. But as these 12-year-olds know, to change a decimal to a percentage one needs to multiply by 100. Hence, odds of 2.3611-1 are represented by 29.752%. The calculations that have been performed are thus: 1 + 2.3611 = 3.3611 followed by 1/3.3611 = 0.29752 and then 0.29752 &times; 100 = 29.752. Overall, this is the same as 100/3.3611 = 29.752. The calculation in the article shows the reader the calculation necessary to achieve a numerical answer of 29.752. Which is the value of the percentage that is equivalent to odds of 2.3611-1. I did not intend them to calculate merely a decimal, which is what your intervention has produced. The article at this point informs the reader of the PERCENTAGE that the odds represent, and the calculation as shown above to obtain THE NUMERICAL VALUE of this percentage. Does the fact that you are a researcher in Maths at university seem to empower you to blindly ignore the intended meaning of the piece in question? Or are you naturally arrogant? I state that I "authored" the article because it was I, in October 2007, who created the page and have been responsible for adding virtually all of the content to the article. This has then been refined by various editors over the last 30 or so months. If you bother to check the edit history of the page you can easily ascertain just how much content I am responsible for and the date of the page creation. I am changing the page back to the way it was originally. Please have the decency to accept that the content that is being questioned by you is actually correct in its intentions as detailed above. I do not wish to get into an edit war with you or anyone else. I will seek editorial assistance/intervention if you persist in changing this aspect of the page content.AirdishStraus (talk) 06:25, 18 May 2010 (UTC)
 * Dear ArdishStraus, we are agreeing on one point: none of us wants an edit war on anything resembling it. I do not know about my arrogance, but I was not the one tossing around academic titles, which have absolutely no relevance here. Nor has any relevance the fact that some particular sentence or turn of phrase has been authored by you or anybody else. WP is a collective work, and nobody can ask some of it to be kept intact on the basis of having written it. And "editorial assistance/intervention" is needed only between editors devoid of any civic sense, which is not our case, I believe (of course, any editor passing by could and should have his say!).
 * So, let us focus on the matter at hand. I believe I understand perfectly well your intentions. The reader might ask, Why is the result such-and-such per cent?, and the article answers, Take 100, divide it by whatever and so on. Do I interpret correctly your words? My single objection is that we should avoid to keep in article an apparently factually incorrect equality. So I suggest to rephrase the sentence along the lines of "Odds of 2.3611-1 represent a percentage of 29.752% (where 29.752 is obtained as 100/3.3611) and multiplying by 4 ...". Would it be agreeable to you? Happy editing, Goochelaar  (talk) 08:36, 18 May 2010 (UTC)
 * Dear Dr Spice, (hope you get the reference... English humour) Mmm... not sure about "tossing around titles", more like just defending my position on being more than qualified to write this article. It is particularly galling to have someone (hopefully unintentionally) nit-picking over an issue that is actually just a mis-interpretation (on your part) of the intention to show what calculation was used to give the value 29.752. My "arrogance" comment may have been a little strong, but reflected my opinion that you seemed intent on "proving a point" as far as technicalities were concerned. Your point did not merit proving, as my calculation was purely a numerical one (29.752 is calculated by dividing 100 by 3.3611). Obviously, to you and I (and maybe some of those 12-year-olds I mentioned), the sum 100/3.3611 gives an answer which actually represents 2975.2%! You mention "factually incorrect inequality". However, I am not trying to state that 100/3.3611 is 29.752%, merely that 100/3.3611 is 29.752. I understand your "olive branch" suggestion of ...(where 29.752 is obtained as 100/3.3611)... but I truly do not think this is necessary. I hope that you will be magnanimous and not insist on any change at all. If you really insist that the existing form of the content is so detrimental to the factual veracity of the article I will reluctantly accept ... 29.752 (100/3.3611) %... which shows, BEFORE the % sign, the calculation. Without "tossing around more titles" [sic] I know this offering to be semantically correct. On a more personal and light-hearted note, any more Maths research posts going spare at Rome Uni??!! My user name gives a (poor phonetic) hint as to my area of expertise and main focus where Mathematics is concerned. I would be interested to know what influenced you to choose the field of Parker vectors. A uni lecturer you had? Simply the type of Maths that "flicks your switch"? I genuinely would be interested to know. Hope you feel like keeping up an agreeable conversation.AirdishStraus (talk) 18:29, 18 May 2010 (UTC)
 * First of all, I do not see what has my real life (even if I give details about it in my personal page) to do with this conversation.
 * As to my suggested amendment, I keep seeing it as the most correct way of saying what we are trying to say, but I'll leave it to other editors to implement it if they deem it necessary.
 * And as to your returning claims to having written this article and to "being more than qualified to write this article", may I recall you Ownership of articles, WP:IMADEIT, and WP:IKNOW? All the best, Goochelaar  (talk) 19:09, 18 May 2010 (UTC)
 * I am sorry you have chosen to go on the defensive. It is rare to meet fellow mathematicians in everyday life. Thus I am naturally interested in what makes you so focused in choosing your specialism. Of course it has nothing to do with the article. So what? I am now sorry I took time to read, understand and appreciate your 80-odd page thesis. Regarding Ownership of articles, WP:IMADEIT, and WP:IKNOW; I am overtly familiar with these article/guidelines. Editors though need to be aware of intention of communication of fact before "ploughing straight in" and changing content. Why not discuss first before hitting the "Save Page" button after making knee-jerk reaction changes to the editorial? I don't profess in the slightest to "own" the article. What I claim is that the content I have contributed is 100% factual, notable and verifiable. And, of course, mathematically correct. I know that there are mathematically competent editors of this page. Very few if any mathematical errors have had the need to be corrected in two and a half years. I am open to the fact that errors might have continually been missed and it has taken this long to correct them. IN SHORT, I wrote the article and willingly accept correction of errors. The article I wrote for WP equals information therefore now in the public domain. I don't own it. But I DO exercise the right to challenge any and all potential alterations to the content, as of course do you. As I wrote the article, alterations need to show conclusively that the original content was incorrect in some aspect or misleading. I do not believe that this is the case in this instance, especially to the general readership who will clearly figure that 29.752 is 100/3.3611 from the information provided. Again, I am sorry that you wish to relinquish the opportunity to have a convivial conversation on a social forum about what you personally find interesting in Mathematics. All mathematicians I know on a personal level seem unable to stop talking about what "flicks their switch". Maybe things are different in Italy. Regards, and fed up with arguing the toss (English expression). AirdishStraus (talk) 21:25, 18 May 2010 (UTC)

Mathematically Challenged
I did a bit of maths at school however I find the explanation of odds and probabilities a bit short. Ie I don't quite understumble. I found this simple example on the web. Understanding the Overround

In a five horse race, a bookmaker may choose to price up each horse at odds of 4/1 (5.0). In such a scenario, were he to take an equal amount of money on each runner, he would break even, as each horse would have a 20% chance of winning. In that the five runners have combined implied "probabilities" of winning of 100%, we are dealing with a "round" book.

Horse 	Odds 	Percent A	5.0	20 B	5.0	20 C	5.0	20 D	5.0	20 E	5.0	20 over-round	- 	100

If however, he were to price up each runner at 3/1 (4.0), the implied probabilty of each runner winning will change to 25% from 20%. If he were again to take an equal amount on each runner, he would receive five units and pay out four. The profitable extra unit amounts to 25% and 25% x 5 = 125%. His book would be 25% "over-round".

Horse 	Odds 	Percent A	4.0	25 B	4.0	25 C	4.0	25 D	4.0	25 E	4.0	25 over-round 	- 	125

The over-round (Vigorish, or simply "vig", or "juice") is what gives the bookmaker his profit, his sun tan and his cigars. If the over-round is 120% the bookmaker will expect to pay out 100 pounds for every 120 pounds he takes in, yielding him an expected profit of 20/120 = 16.7%.

Place Odds
I don't grasp the way place odds are calculated either. Is it the win odds divided by the number of starters plus 1? I may have somehow missed the explanation of that.

Oh as for the name I came upon this via a search for overround.(I'd never heard of the term before.)

As for original research discussion, I don't think originality applies to mathematics which is subject to rigorous proofs rather than reference to authorities. Anyway thanks to the community for this article. Its helped me.Nnoddy (talk) 00:43, 30 June 2011 (UTC)

Harville & Henery Models
These models are referred to often on literature and were subjected to a sequential probability ratio test (SPRT)based on Belmont USA race results. (As predictors for exacta bets) http://libra.acadiau.ca/library/ASAC/v26/02/26_02_p032.pdf

Place odds appear problematic. — Preceding unsigned comment added by Nnoddy (talk • contribs) 01:04, 1 July 2011 (UTC)

Overround on multiple selection bets
Would be nice having an explanation of bookmaker overround on bets like forecast or tricast. They are very common on fixed odds bets on virtual races.

Bye — Preceding unsigned comment added by 217.175.51.15 (talk) 15:55, 16 September 2011 (UTC)

I am confused about this - "19% instead of 9% on an event; in this case the double" shouldn't it be         - "19% instead of 18% on an event; in this case the double"  ? Because the current statement, is like comparing the bookie profit of a single bet, but it should be comparing the double to two single bets ? — Preceding unsigned comment added by 2407:7000:986C:1300:A81A:F32E:1F72:ECEE (talk) 20:11, 11 December 2021 (UTC)

Wrong calculation
£100 × (1/1 + 1) × (11/8 + 1) × (5/4 + 1) × (1/2 + 1) × (3/1 + 1) = £6412.5 not 641.25  — Preceding unsigned comment added by Sielay (talk • contribs) 17:51, 13 February 2015 (UTC)

Blacklisted Links Found on Mathematics of bookmaking
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Blacklisted Links Found on Mathematics of bookmaking
Cyberbot II has detected links on Mathematics of bookmaking which have been added to the blacklist, either globally or locally. Links tend to be blacklisted because they have a history of being spammed or are highly inappropriate for Wikipedia. The addition will be logged at one of these locations: local or global If you believe the specific link should be exempt from the blacklist, you may request that it is white-listed. Alternatively, you may request that the link is removed from or altered on the blacklist locally or globally. When requesting whitelisting, be sure to supply the link to be whitelisted and wrap the link in nowiki tags. Please do not remove the tag until the issue is resolved. You may set the invisible parameter to "true" whilst requests to white-list are being processed. Should you require any help with this process, please ask at the help desk.

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 * http://www.bjmath.com/bjmath/thorp/tog.htm
 * Triggered by  on the global blacklist

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From your friendly hard working bot.—cyberbot II  Talk to my owner :Online 00:37, 14 August 2015 (UTC)

Colloquialisms may impede usefulness
I found that this page utilizes highly colloquial language quite a bit; in some cases it is simply topic-specific jargon that could be deemed appropriate, especially if the specific terminology is used by English speaking bookmakers worldwide (e.g. fair book). In some cases, however, it is certainly region specific jargon (e.g. Evens) or even simply slang (e.g. punter). Not being an expert on the source matter, I'm very (very) hesitant to attempt to make any changes, however I figured it would not hurt to suggest a review of specific terminology, by someone in the know, to try to reduce the highly localized language on a topic that is applicable on a very worldwide basis. 68.116.66.38 (talk) 21:24, 18 April 2016 (UTC)
 * 'Evens' is betting industry standard speak for odds of one-to-one. 'Punter' is not slang, it is a person who punts (i.e. one who places a bet or wager, or who makes a highly speculative investment).The word 'bettor' is somewhat equivalent but is rather formal and rarely used in everyday language. AirdishStraus (talk) 08:47, 20 April 2016 (UTC)


 * The OP has a point. "Punter" is British slang. In the US the person making a bet is a bettor or a gambler. Similarly "even odds" or "even money" is more popular in the US than "evens". On the other hand I don't think it is a problem in the article as the translation of punter to bettor is right there at first use. I've added a link to even odds at the first use of "evens". --Mark viking (talk) 10:12, 20 April 2016 (UTC)