Gaming Guru: Why doubling up your bet after a loss could be trouble down the line

Print
Font Size:
Default font size
Larger font size

Posted: Thursday, April 26, 2012 12:05 am

The Martingale betting system, in which players double their bets after losses, has a strange hold on a segment of roulette players. I've been warning against the system since I started writing regularly about gambling in 1994, and others exposed the system as a bankroll-eater long before I joined the fray.

And yet it's a rare month when someone doesn't ask me about the Martingale, whether by email or in person. To some, it's new, something they've heard from a friend. Others have read that it's a bad, costly system, but wonder if maybe if those issuing the warnings have missed something.

Daryn is one of the latter. He approached me in a casino to say he's been having success in the casino.

"I heard that one of the drawbacks is that sometimes you can't bet enough money to keep it going, because of the table limit," he said. "Well, I found a casino where the minimum bet is \$5 and the maximum \$1,000, so I can do an eight-step system. I bet on red or black. So tell me, what are the chances of losing eight in a row?"

I didn't know offhand -I guessed somewhere in excess of half a percent - but it's easy enough to calculate. There are 38 numbers on a double-zero wheel. For any bet with an even-money payoff, including red, black, odd, even, first 18 and last 18, there are 18 winners and 20 losers. The probability of eight losers in a row is 20/38 raised to the power of 8. In the wi-fi age, we could get the answer on the spot by typing "(20/38)ˆ8" into Google. The result: a little less than 6 percent, 0.589 percent, to be more precise.

"See? That's practically nothing," Daryn said. "I've tried it four times now, and won every time."

In my view, that's not practically nothing. It's once per 169.84 trials - love that calculator function. And when the losses come, they are spectacular.

One of the features of a Martingale system is that whenever you win, your profit is equal to your initial wager. If you bet \$5 to start, as in Daryn's table with the \$5 minimum, and you lose, you then double up and bet \$10. A \$5 loss followed by a \$10 win means an overall profit of \$5.

What if you lose at \$10? Then the Martingale calls for you to double up again and bet \$20. Losses of \$5 and \$10 followed by a \$20 win leave an overall profit of, yes, \$5.

So it goes with every step in the Martingale. In Daryn's eight-step progression, in a losing streak he'd bet \$5, \$10, \$20, \$40, \$80, \$160, \$320 and \$640. A win on any one of those bets would give him a \$5 profit, then he'd go back to \$5 on his next bet to start a new progression.

If he loses all eight bets, losses total \$1,275. I don't know about your bankroll, but mine can't stand many \$1,275 losses in pursuit of a series of \$5 profits.

"That's all well and good, but those losses are rare," Daryn said. "You showed me yourself, it's happens SIX-TENTHS of a percent of the time."

It doesn't have to happen often, I told him, because when it does, it wipes out all wins and then some. With 169 small wins at \$5 each for a total of \$845, and one \$1,275 loss in the average 170 trials, Daryn's Martingale is a \$430 loser.

Given enough chances, anything that can happen eventually will, and you never know when the big loss is coming.

Gambling author and columnist John Grochowski's weekly newspaper column began at the Chicago Sun-Times and is now syndicated nationally. He also regularly makes TV and radio appearances about gambling. His column appears weekly.