Probability that this scenario happens

[Chris2b]

Hi All, Team A has 20 games in a row whitout draw. Odds for draw = 3.50 What is the probability that this scenario happens ? thank you very much help ;)

[zbrochu]

Re: Probability that this scenario happens There has not been raining for 21 days, what is probability of rain today? It all depends on the method you use. You can have your own model for predicting rain, or you can use neural network, artificial inteligence or you can just guess. If you are asking what bookmakers think is the probability of draw, with given odds: 1.70-3.50-5.7 then correct answer is : 26.8% PS: I do not think that fact that Team A has 20 games in a row without a draw has any influence on probability of a draw in this game.

[Chris2b]

Re: Probability that this scenario happens Hello zbrochu and thanks for your answer. I mean like toss : 2.00 - 2.00 the probability that tails don't happen 10 times in a row is 1/1024. and for without draw 20 times in a row if odd = 3.50 ? thnak you for give me the calculation. Chris

[froment]

Re: Probability that this scenario happens You did not explain well what you wanted - I thought the same as Zbrochu, thought that you asked what is probability of team to be quoted 3.50 for draw after 20 drawless matches.

and for without draw 20 times in a row if odd = 3.50 ?

Apply the same logic as for the toss of the coin: probability of 20 consecutive tails or 20 consecutive not tails is 2.00^20. If draw is 3.50, probability is 100/3.50 = 28.57%; probability of not-draw is 100-28.57 = 71.43%; therefore, probability of 20 consecutive non-draws is 0.7143^20 = 0.0012 = 0.000012%. However, important difference between toss of the coin and draw is that you know probability of tail / head is exactly 50% (or it's not?... read here! ;) ), while probability of a draw is subjective value - the bookmaker you quoted believed it was 28.57%; I might have come with value of 25%, Zbrochu might have evaluated it at 32%, etc...

[Chris2b]

Re: Probability that this scenario happens thank you froment for your help. if we have better probability that draw happen after 20 consecutive not-draws , it will be interesting to know if betting draw @3.50 for match 21 is a value or not. Just mathematic not statistic.

[froment]

Re: Probability that this scenario happens

Just mathematic not statistic.

Now, you can freely apply Zbrochu's answer above - probability of match to end in any of three outcomes does not depend on outcome of 20 previous matches. In reality, it may slightly affect the match, in terms that team may be experiencing good or bad streak, thus feeling the pressure to make good result (or the same pressure preventing them from making good result, depending on mental stability of the team), but still, if team has run 20 matches without draw, it cannot prevale when estimating chances of 21st match to end in draw.

[Max2112]

Re: Probability that this scenario happens TBH purely taking previous results into consideration has very little to do with the result of the next game There are dozens of factors that affect the result - try the 0.5 goal challenge - you'll see that if team A averages 3 goals a game and team B averages 2 then there is still a chance of a 0-0 :( If a team hasn't drawn in 20 games the probability of a draw is still around 30% (depending on league) - exactly the same as the very first game in the run

[zbrochu]

Re: Probability that this scenario happens Some very good posts by Froment, I fully agree. I hope you do not consider Martingale Chris. Each time I see someone asking about probability of any streak on the forum, I feel obliged to warn them about progressive staking plan.

[Chris2b]

Re: Probability that this scenario happens Thanks zbrochu, froment and bazzdude for your comments i do not consider martingale. Just some few paper testing... without success :\ paper testing was : - take team with 10 consecutive non-draw - objective : win 1U / bet - adjust stake in function of the odd and objective the worst serie that i found is RAYO VALLECANO 2011-2012 : 29 consecutives non draws ! i don't know if this is the worst serie of the last 10 years, but she's quite big. we start at 10 consecutive non draws 1st bet : stake 0.40€ U @3.47 lost AND 19TH BET : stake 333 U @ 3.57 won won total profit for this serie = 19U (total stake for this extreme serie = 1171 U) : yield for this serie : 101.5% i'm pretty confident about this staking plan. the problem is somewhere else. the problem is that this serie happen when i increase initial stake from 1U to 1.5U after 1000 U won (for example). we have 2000 U bankroll. increase of 0.5U is ridiculous. So, the damages are huge !! it's probably the bankrupt if we have this extreme serie + another following serie with 10 bet. that's why i try to take information for find flaws in my paper testing. Thanks again :) Chris

[Max2112]

Re: Probability that this scenario happens The most important thing about staking is that NO system that makes a loss at level stakes will ever show a profit using a staking plan (unless you have unlimited funds) And if you are staking a million quid to make a series profit of £1 then you will have a heart attack :D The worst thing a punter can do is chase losses - your heart over-rules your head and you make stupid decisions When I was a Ladbrokes (Boo!) manager I saw a guy blow over £100k in one day by doubling up his stake hoping for a winner - he almost had a stroke when he lost a race on a Stewards early in the (bad) run:D

[Chris2b]

Re: Probability that this scenario happens yes it's finally a bad thing for only one reason : - a serie of bad ciconstances will fall one day that will lead to bankruptcy. it is enevitable.