Talk:Martingale (betting system)

message: Roulette is a game of pure chance - there is no skill - every number has an equal chance of coming up but the payouts are made at under the odds. Roulette is a NEGATIVE EXPECTANCY GAME - every time you bet on a number you are betting into a negative return in the long run. NO method works. In practice casinos couldnt care less about Martingale or any other theory.
: It seems people here simply don't get that. THere are no more red/black squares appearing after spins, so no matter how much you bet or when you bet it, the chance of red/blaack spinning up does not change. It doesn't help that the article is poorly written either. There are mathematical proofs on the merge page that show why it won't work for gambling, there is also the Kelly Criterion which shows that the optimum bet for a game with a house edge is negetive (ie be the house or don't bet at all). These are 100% mathematical proved and verified. Of course Martingale will always be popular and has been since medieval times. --155.144.251.120 22:15, 21 December 2006 (UTC)
thread_title:  A more simple analysis 

message: It is proposed to merge this "with" martingale (probability theory).  It would be more plausible to merge this into that article.  There is a "mergeinto" template for that purpose. Michael Hardy 19:46, 13 September 2006 (UTC)
replies: text: There are three Martingale articles.  I'd only merge this one if the third one was merged too.  Otherwise, since this is so wildly different than the probability article it should also be kept separate.  Anyway, if the paradix one is merged too, that seems best. 2005 22:51, 13 September 2006 (UTC)

text: Support This article could be a footnote of the probability article. Then, you could take out all the uncited stuff and make it into a useful side comment. GumbyProf: "I'm about ideas, but I'm not always about good ideas." 05:00, 17 September 2006 (UTC)

text: I'd support merging all the articles. They're all on the Martingale system, and merging would make the information easier to access. IMHO. 71.89.61.239 02:15, 20 October 2006 (UTC)

text: Support merge.  It can and should be added to the Martingale as it only an implementation of this theory. JeffyP 20:27, 29 October 2006 (UTC)

text: Support merge. You can always redirect hits to this page back to the main one. And I agree, this is an implementation of the theory. Obscurans 20:59, 3 January 2007 (UTC)

text: Keep I agree with his keep. Many people do not know it as the 'martingale' but as the 'double up' system or progression betting etc.--155.144.251.120 22:15, 21 December 2006 (UTC)

text: Keep I agree that it's a good thing to have two different articles, even though they could cross-reference each other better. As I understand it, readers here fall into two quite different groups (mathematicians and gamblers) and consequently they expect two quite different accounts of the matter. iNic 00:18, 7 January 2007 (UTC)

text: Keep The Martingale (betting system) article is written mostly in standard English, and is an easy article to read for those simply interested in the progression betting or "double-up" gambling system.  The Martingale (probability theory) article contains much that is written as statistics and probability equations, and is unintelligible to many readers without advanced study of such systems. StavinChain 17:58, 25 May 2007 (UTC)

text: It is not incorrect, it simply does not explain exactally what a session is, but obviously it needs re-writting.--155.144.251.120 22:15, 21 December 2006 (UTC)
thread_title: merger?

message: Would it make sense to add a bit here about Nick Leeson, who destroyed the Barings' Bank with what was in effect a martingale series of bets of the Nikkei index? --Christofurio 04:25, 4 January 2007 (UTC)
replies: text: I just read that article but couldn't find any support for a connection to martingales. iNic 00:18, 7 January 2007 (UTC)
replies: text: There are some similarities in that it appears he kept betting more and more (with riskier bets) in an attempt to recover the money he had lost, I presuming hoping he would eventually make it all back. Also see Barings Bank. Nil Einne 01:36, 25 April 2007 (UTC)
replies: text:  A closer example would be the collapse of LTCM, which made "sure thing" bets with small profits, but after a streak of bad luck, was forced to come up with too much capital and went bust.  They claimed that had there not been a margin call, they would have made it all back in a few months, a frequent martingale claim.  —Preceding unsigned comment added by 132.228.195.207 (talk) 21:40, 31 March 2009 (UTC)
thread_title: Nick Leeson

message: I just re-wrote most of the article and put in correct math. Feel free to improve it.
On an unrelated note, does anyone know the origin of the term "martingale", and how it's related to this betting system? --Spoon! 10:58, 22 January 2007 (UTC)
thread_title:  re-written 

message: The math here still looks incorrect.  It claims that the expected profit is (...), but does not take into account the fact that one could win x times in a row - I.E., the math is basically as follows: P(neverWinning) * amountLost + P(winningAtLeastOnce) * amountWon, but the amountWon increases if the player has won more than once and this is not taken into account.  The formula only assumes that the player wins once and stops playing.  
As an example, note tha the current formula shows the correct payoff if there are consistent losses on all x plays, but does not show the correct payoff if there are consistent gains on all x plays.  The correct way to show the expected payoff of a martingale involves combinatorics and the series of corresponding payoffs and probabilities.  Luckily, the series can be reduced to a closed-form solution.  "I have a wonderful proof of this fact which the margin is too small to contain."  (I hope to have more time to update in the next few days)
We should also show a graph that illustrates the Martingale payoff. —The preceding unsigned comment was added by 66.65.160.193 (talk) 02:21, 25 April 2007 (UTC)
replies: text: I think you have totally missunderstood the formula. It applies generally. Having a combination of the payoffs and probabilities is impossible, because it will be infinite if the player has infinite money. That is why the formula includes how much they have. Martingale is very simple, you are trying to win 1 unit, risking all of your money to do it. It doesnt matter how many times you do this.--58.108.249.77 09:24, 6 June 2007 (UTC)
thread_title:  Formula still looks wrong to me 

message: The example is misleading. It is comparing a loss per round with a loss per roll and indicating that there is a difference in the edge. Martingale makes no difference to edge. Objective3000 (talk) 12:02, 18 April 2008 (UTC)
thread_title:  Example 

message: Added for the obvious: an article shouldn't be calling anyone 'foolish', etc.  —Preceding unsigned comment added by 219.73.23.140 (talk) 15:10, 24 May 2008 (UTC)
thread_title:  POV 

message: It's unlikely that you'll lose any money by withdrawing it at profit at some point if you have a lot of money and play with smaller bets. This is just stupid absolutistic idealistic analysis of a situation where you play for an infinite amount of time. Well, duh, Einstein, how is that possible in real life? Gambling is by definition not risk-free. This is an alright strategy :) --nlitement [talk] 21:45, 30 May 2008 (UTC)
replies: text: Well, yes, it is true that this strategy usually results in positive payouts if one plays for brief periods of time and only leaves immediately after a win.  However, this strategy sometimes leads to catastrophic losses, and the net effect of these catastrophic losses outweighs the net effect of the meager winnings assuming a house edge.  This doesn't need to be idealized to infinite time played, but merely shows that the Martingale system doesn't improve your pot odds.  So obviously this strategy is fine if one assumes that a high probability of winning a low amount of money inherently outweighs a low probability of losing a proportionately high amount of money -- in fact, there might be cases one could contrive where this would be true (for example, if one needs just $1 more to pay off their $1,000,000 debt, and if that dollar is not earned the whole of their $1,000,000,000 estate will be lost).  However, most of the time the exact opposite is true (if one takes a realistic utility function into account, for example) to a high degree, making the Martingale system WORSE than a system where one bets the same amount on every play.  And no matter what, in terms of mathematical expectancy, the Martingale system changes nothing.  Eebster the Great (talk) 02:12, 28 September 2008 (UTC)
thread_title:  Silly mathematicians 

message: Let's say you have an infinite bankroll and want to guarantee yourself $5,000,000,000.  That's five billion dollars.
You can follow these simple steps
# walk out of the casino into a bank
# open a bank account.  In the step below I propose a method for getting $5 billion into that checking account (if you have an infinite bankroll), WITHOUT affecting your infinite bankroll!
# write yourself a check for $5b
# deposit it into the new account
# The bank will deduct the five billino from your bankroll, which will continue to have infinite money in it.
# Therefore, you have just gotten a guaranteed five billion dollars without affecting your bankroll!!! (if you have an infinite bankroll).
Can anyone see any problems with this theory???
: You're right, but there's nothing special about this betting strategy that allows this. Simply betting a dollar on a (fair) coin flip enough times will ensure that you will eventually win some fixed arbitrary amount. This phenomenon is called recursion, and is fairly common. 142.1.133.165 (talk) 16:07, 13 March 2013 (UTC)
replies: text: Try it and come back and tell us how well it worked.Objective3000 (talk) 00:40, 9 February 2009 (UTC)
replies: text:  they said I need two proofs of ID which I didn't have :(  —Preceding unsigned comment added by 82.120.236.246 (talk) 11:10, 9 February 2009 (UTC)
replies: text:  You're wrong.Objective3000 (talk) 17:50, 11 November 2009 (UTC)

text:  Objective3000 is right, you're wrong.  Assuming an infinite number of players, several of them will have losing streaks longer than their life spans.  This makes up for the winning players and brings the average win/loss exactly inline with the house edge of the bet in question. AddBlue (talk) 07:24, 20 February 2012 (UTC)
thread_title:  the article doesn't state that if you have an INFINITE bankroll you can guarantee yourself money AND keep your bankroll! 

message: Could someone explain me how to get the value for probability of 6 concesutive losses within e.g. 60, 152, 250 spins (like it is in section Alternate Mathematical analysis of a single round)? If you were able to give me some general formula for it I would be very thankful. Or just link me some site with explanation how to count it. I found it hard to deduce some formula on my own. Thank you very much.--Bab dz (talk) 20:14, 5 May 2009 (UTC)
thread_title: Mathematical question

message: I acctually thought of this theory without any help when i was 12 years old, was planning on trying it out today then looked it up and it seems to be v well known. 
Anyway, why is everyone using examples of loosing 6 times in a row. taking up the example of having $6,300 why not bet smaller stakes, say, starting at $10 then you have a much greater chance to win? (10 / 20 / 40 / 80 / 160 / 320 / 640 / 1280 / 2560/ 5120) - 10 losses in a row to loose! Now i havn't thought about this alot but the only reason i can think for not doing this is you will be winning tiny stakes :S
Very much appreciating replies ^^  —Preceding unsigned comment added by 212.239.170.3 (talk) 18:06, 20 May 2009 (UTC)
replies: text: What's the use of a great chance of winning, if you just win tiny amounts, along with staggering losses when you eventually lose? --76.173.203.58 (talk) 04:34, 22 May 2009 (UTC)
thread_title:  Smaller bets = much higher win chance? 

message: The system not only requires the player to have an unlimited bankroll, it also requires the casino to have unlimited solvency so it can keep paying off possible wins as the stakes increase.83.5.167.4 (talk) 09:26, 3 July 2009 (UTC)
thread_title:  Unlimited bankroll 

message: so the odds for a 10x streak of coin flips would be 1023 to 1 against, I believe but with ENOUGH flips the odds of having ten consecutive heads are even, and at some yet larger number of flips  the odds of NOT having ten consecutive heads is 1023 to 1 against. am i thinkin about this the right way? is that why cant think of it as not playing the static 50/50 odds but playing the odds for streaks.. because the odds are dynamic based on number of case sets? id love any clarification.  —Preceding unsigned comment added by 98.212.231.88 (talk) 16:07, 23 February 2010 (UTC)
thread_title: Odds for extended streaks in Martingale

message: I have just added some new text, probably too wordy, under "mathematical analysis".  It's my first logged-in Wikipedia edit, and a bit of an experiment to see if I can do it right.  I think there is some duplication of material already present in the article, but I preferred not to change anything written by others at my current level of experience.  
My goal was to provide a more mathematical discussion of the "certain to win eventually" property at a reasonably elementary level, and to show its inapplicability to the real world in a different light than just negative expectation under bounds on time or money (which is also true, of course).  —Preceding unsigned comment added by Styrofoams (talk • contribs) 02:17, 19 March 2010 (UTC)
thread_title: Some more mathematical material

message: if p=1/k and the bets increase a(n+1)=(k+1)*a(n), then the win with p=1/k will lead to getting 1 initial bet. Станислав Крымский (talk) 16:32, 11 July 2012 (UTC)
thread_title:  з 

message: Arbitrarily large, not infinite wealth: w
Probability of winning: p=4/5
Return on winning: r=3/4
Multiplication factor:  f=999.....99999
First bet: x[0]=1;
Next bet: x[n]=p*x[n-1]
For a general formula:
Given w[0], p[n], r[n] and r[n]<p[n] one may use Numerical methods to compute f[n] and x[n] along with w[n]; risk may also arise from the error resulted from the approximation discrepancy between rational and non rational, but real numbers.
Someone might be interested in correcting what appears on the Roulette article. 79.117.44.240 (talk) 16:17, 10 December 2013 (UTC)
thread_title:  Example of a "generalisation" 

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thread_title:  External links modified 

message: The strategy does work... in a perfect casino only.
Why it failed to work in real casinos?
For the probabilities of big games are always deliberately manipulated using out-of-the-system methods.
And the game tends to eventually end up in a shooting game between the player (and/or whose representatives) and the casino's personnel, which would very likely end up very violently...
— 154.48.253.21 (talk) 11:32, 11 February 2020 (UTC)
replies: text: Sorry, but this is absurd on multiple levels. Most importantly, martingale does not work as explained by the article and this has nothing to do with any casino manipulation. Further, the accusation of violence is ludicrous. Please use reliable sources. O3000 (talk) 15:01, 15 February 2020 (UTC)
replies: text: No, game manipulation has absolutely nothing to do with why Martingale doesn't work. O3000 (talk) 13:12, 16 February 2020 (UTC)

text: Not true, because the gambling method could preclude the tenets of gambler's ruin. An adequately bankrolled, fractional Kelly better in a positive expectation game is not subject to ruin. And please stop using tq2 and read WP:INDENT. Your threads violate our procedures. O3000 (talk) 15:12, 16 February 2020 (UTC)

text: Wikipedia is not a place to publish these rants. Please publish in a paper (Reliable Source) then it might be cited here. Limit-theorem (talk) 15:00, 16 February 2020 (UTC)
replies: text: Agree. O3000 (talk) 15:12, 16 February 2020 (UTC)

text: Your edits are unreadable and you are clearly WP:NOTHERE. Don't expect further responses and don't ping me. O3000 (talk) 17:41, 16 February 2020 (UTC)
thread_title:  The neglected scope