Roulette percentage over 5 bets

Hi, I just joined the site, searched for my question and didn't see it so I'm posting it. I just came off a cruise playing more roulette than usual and doing well.
Here was my method:
Spin 1: $5 on 1st 12
Spin 2: $10 on 1st 12
Spin 3: $15 on 1st 12
Spin 4: $20 on 1st 12
Spin 5: $25 on 1st 12
If at any time I won, I started over at Step 1. If I lost, I increased by $5. If I lost 5 in a row, I accepted my $75 loss and started over with $5.

I know that I'm wrong but my rough calculation is I have 4 spins to make money and the 5th to break even on a bet that has odds of 31.57% of hitting. I know I'm missing something but don't know what.

Thank you for your help

it does not matter what you do or how you do it.....eventually on roulette you will lose 5.26% of your bets.

Quote: 8laylock

I know that I'm wrong but my rough calculation is I have 4 spins to make money and the 5th to break even on a bet that has odds of 31.57% of hitting. I know I'm missing something but don't know what.

What you're missing is, when you win, you tend to win small, and when you lose, you lose big.

Assuming a double-zero wheel (since you say you have a 31.57% chance of winning):
6/19 of the time, you win your first bet, and end up +10
13/19 x 6/19 of the time, you lose your first bet and win your second, and end up +15
13/19 x 13/19 x 6/19 of the time, you lose your first two bets and win your third, and end up +15
13/19 x 13/19 x 13/19 x 6/19 of the time, you lose your first three bets and win your fourth, and end up +10
13/19 x 13/19 x 13/19 x 13/19 x 6/19 of the time, you lose your first four bets and win your fifth, and end up even
13/19 x 13/19 x 13/19 x 13/19 x 13/19 of the time, you lose all five bets and end up -75
The expected result is (6/19 x 10) + (13/19 x 6/19 x 15) + (13/19 x 13/19 x 6/19 x 15) + (13/19 x 13/19 x 13/19 x 6/19 x 10) - (13/19 x 13/19 x 13/19 x 13/19 x 13/19 x 75), or about -1.61839 per "run" (until you win, or lose 5 in a row).

From a distance, when looking at Don's post, you have to win at least 6x more often than you lose. Sounds easy, but it will catch up.

You are doing a version of the Martingale system. And in the long run, it won't work.

There's lots of research on it, on the internet.

It's not much different than any other system,

In short, it looks great on paper.

In fact, it works fine in a casino.

Until the one time that it doesn't. Then it's a complete financial disaster.

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Here's a homework assignment for you:

Go to a casino and look at the history displays for all the roulette tables there. Check how many times you see a series of six or more numbers that completely miss one of the dozens.

How many spins in a row did it miss that dozen? Seven? Eight? Ten? More?

Can you see how easy it is to lose?