Doubles System

When betting I almost exclusively use single bets and would recommend that to everybody, but there is one single exception. Exception is using Doubles System. I've been using this system for more then five years now and it has shown a constant profit ever since. Double is an accumulator bet which includes two selections and both must win for the bet to win.

This system shows best results when betting on 50-50 selections, fixtures where both outcomes have (more or less) same expectation. Those bets are NBA spread and total bets; NFL spread and total bets; MLB total bets and MLB sides bets with odds from -125 to +110 (1.80 to 2.10 in decimal odds). Odds for each selection should be around -110 (1.91 in decimal odds).

If one selection has 50% chance of winning than double would have 25% chance of winning. This means that in the long run every 4th double bet would be a winner. Now, let me explain how to use this Doubles System. There is a simple formula that tells us how much money to bet each time:

YB = (EP + TL) / ((ODDS1 * ODDS2) – 1)

EP – Expected Profit

TL – Total Loss (sum of all losing bets in a series)

ODDS1 – Odds for first selection in decimal odds

ODDS2 – Odds for second selection in decimal odds

Expected Profit is flexible, but the higher the profit greater the chance of losing your bankroll in case of bad run. I would suggest moderate EP (let's say 2 units) at the beginning and then to increase it up to 2.5 or 3 units.

For example let's assume that each time we bet, both selections will have odds of 1.91 (-110 in American odds). This means that our double will have odds of 1.91 * 1.91 = 3.65 (I would suggest accumulated odds between 3.00 and 4.50). Also let's suppose our bankroll is \$1000 and our unit is \$10 and that our expected profit is two units = \$20. Our first bet would be:

(\$20 + 0) / ( 3.65 – 1) = \$7.54

We lose, then our next bet is:

(\$20 + \$7.54) / ( 3.65 – 1) = \$10.39

We lose again, our next bet is:

(\$20 + \$7.54 + \$10.39) / ( 3.65 – 1) = \$14.31

And again we lose, next bet is:

(\$20 + \$7.54 + \$10.39 + \$14.31) / ( 3.65 – 1) = \$19.71

Now, this bet is a winner, return is \$19.71 * 3.65  = \$71.94 and after we deduct all placed bets in the series we are left with profit of \$71.97 - \$19.71 - \$14.31 - \$10.39 - \$7.54 = \$20. After every winner our profit in the series will be 20\$, series ends and next bet will be:

(\$20 + 0) / ( 3.65 – 1) = \$7.54

Continue betting using the formula until hitting a winner and then again start the series from the beginning.

As I said before, if you only bet on fixtures with odds of around 1.91 (-110 in American odds) on the long run every 4th bet would be a winner. If we place one bet each day for a year we can expect to win 365 / 4 = 91.25 bets or to make a profit of 91.25 * \$20 = \$1825 and this is with a moderate unit of just 1% of the bankroll and the expected profit of 2 units.

What I do is to wait until doubling my bankroll, then I stop, recalculate the bankroll and new unit size and then continue from the beginning.

Of course, there will always be a cold streak or two, but in example of \$1000 bankroll and \$10 unit it would take 12 straight losing bets to lose your bankroll and with this odds it's statistically virtually almost impossible. Almost I say, but just to be on the safe side set yourself a limit of how much losing bets you can afford. Just as long as you follow a few simple rules this Doubles System will generate constant profit:
1. Make a double bet using the formula
2. If first double is a loser make another double bet and continue to do so until you hit a winner
3. If you win, start the next series from Step 1