Stay on track at casino by knowing road to ‘ruin’

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Updated: November 9, 2011 12:19PM

A friend of a friend put me in touch with George, a casino player with a question of bankroll:

“How much is enough?” he wanted to know.

I answered with a question of my own: Enough for what?

“Enough so I can play awhile,” he explained. “When my wife and I play, she sticks to the penny slots, and it seems like she can milk a couple of hours out of 40 or 50 bucks. I play blackjack, maybe a little roulette. So if we want to play for two hours, have a buffet and go home, how much money do I need?”

That depends on the game, the size or your bets and, in some cases, your skill level. It all ties into a concept called “risk of ruin.” Given a certain game, bankroll and number of plays, what is the likelihood that you’ll lose it all?

George is a blackjack player, so I asked him if he knew his basic strategy.

“I do,” he said. “I learned it years ago.”

That’s a good thing, I told him. Blackjack is a relatively even-keel game. For a 90 percent chance of lasting an hour at 100 hands per hour, it takes about 18 to 20 betting units. There’s some variation depending on speed of play and house rules, but we can generalize and say it takes $100 for a 90 percent chance of staying alive at $5 a hand, or $200 at $10 a hand.

For two hours, it’s more like 25 to 30 units, or $125-$150 at $5 a hand, or $250-$300 at $10.

“OK, what about roulette? I just try to make my money last, so I mostly bet red/black and odd/even, maybe sometimes the columns.”

Roulette has a higher house edge than blackjack, but it also is played at a slower pace. That means if you stick to the wagers with even-money payoffs — the odd/even and red/black options George mentioned plus first 18/last 18 — it takes only about 12-15 units for a 90 percent chance of lasting an hour, and 18-20 units for two hours. A $100 bill gives you a 90 percent chance of surviving two hours if you make only one $5 wager on the even-money bets per spin of the wheel.

“If you make more than one bet, you need more bankroll. That makes sense,” George said.

Craps is similar. A 12-to-15-unit bankroll has a 90 percent chance of giving you a two-hour run if you make only pass line bets, but how many players do that?

“I wouldn’t know,” George said. “Not my game. But thanks for the blackjack and roulette info. It sure seems like the money goes faster sometimes.”

It sure does, but remember, these are only 90 percent chances. A 90 percent chance of lasting still means 10 percent of running out of bankroll.

John Grochowski is a local free-lance writer. His “Casino Answer Man” tips air at
5:18 p.m. Tuesday-Friday on WLS-AM (890).