Martingale with draws

[Tonyvdb]

I have been looking at the following : Martingale with draws. 1. This is my (so far theoretical) strategy : I do several bets at the same time, with 5 EURO to win each time. When I win the bet, I put 5 EURO in my virtual account. When I lose the bet, I add the stake to the second bet. When I lose the 2nd bet too, I add that stake to the 3rd one, ... 2. example : *Bet 1 : draw @ 3,20 : stake : 2,30 € (to win 5,06 EURO) - Draw : I win 5,06 EURO and put that money in my virtual account. - No draw : I add the stake of 2,30 € to bet 2, again to win 5 EURO *Bet 2 : draw @ 3,55 : stake : 2,90 € (to win 5,04 EURO) - Draw : I win 5,04 EURO and put that money in my virtual account. - No draw : I add the stake of 2,30€ + 2,90€ to bet 3, to win 5 EURO *Bet 3 : draw @ 3,35 : stake : 4,35 € (to win 5,02 EURO) - Draw : I win 5,02 EURO and put that money in my virtual account. - No draw : I add the stake of 2,30€ + 2,90€ + 4,35 € to bet 4 ... *Bet 4 : ... and so on ... 3. conclusion : - I have 3000 € I can afford for betting : as long as I have a draw in the first 12 bets, or even 15-16, it is still affordable. Problems would arise however as soon as I have a losing streak of 17 draws or more. 4. Now I would want to ask to you, who are involved with probability-formula's and so the important question is : How big is the chance you have 15 losers in a row, with - let's say - 3,50 fair odds ?

[Rob]

Re: Martingale with draws I believe the odds of 15 wrong in a row are: (1/3.5)^15 = 0.0064 i.e 0.64% or about 150/1