Oscar's System

Aiming to win one unit at a time

Oscar's system involves increasing your bet by one unit every time you win. However, the goal of the system is to win just one unit from each sequence, so if you win your first bet, the system is complete and you start over again.

So the system only really comes in to effect after you have lost your first bet.

Furthermore, the goal is to win just one unit. So if you are approaching a profit after a series of wins, you sometimes have to adjust your bet size so that it will be sufficient to result in a one unit profit only (if you were to win on the next spin).

Oscar's System:

  • If you lose, you keep your bet size the same.
  • If you win, you increase your bet size by one unit.
    • If you're approaching a profit, adjust your current bet size so that it will only result in a profit of one unit.

If you reach a profit of one unit at any point, the system is complete.

So it's a simple system where you just aim to win one unit by adjusting your bet size (usually increasing it by one unit) every time you win. When you win one unit, you start the system over again and carry on.

Animation showing usage of Oscar's system in roulette

How does Oscar's system work?

It's quite a simple system, but the best way to explain it is with a few examples.

Here's a classic example of the system in action:

Bet Size: 1 1 1 1 1 1 2 3
Result: L L L L L W W W
Balance: -1 -2 -3 -4 -5 -4 -2 +1

In the next example we do not increase the size of our bet when we win, because it would have the potential of giving us a profit greater than one unit:

Bet Size: 1 1 1 1 1
Result: L W L W W
Balance: -1 0 -1 0 +1

Similarly, the next example shows us limiting our bet size increases to prevent a profit greater than one unit, but also shows us increasing our bet size at other stages along the way.

Bet Size: 1 1 1 2 2 2 2 2 3 1 1 1 2
Result: L L W L W L L W W L L W W
Balance: -1 -2 -1 -3 -1 -3 -5 -3 0 -1 -2 -1 +1

So as I say it's a simple system: you just increase your bet size by one unit when you win, but augment that bet size if you're going to exceed the holy grail of a one-unit profit.

Note: These examples are taken from the original book the system was first described in (see below).

Oscar's system simulation

Note: This simulation gives you the option of repeating the system a given number of times for a greater overall profit. I don't imagine anyone uses the system just to win one unit, which is why I've included the repeat option.

The simulator also stops after a maximum of 5,000 spins.

As you can see from the chart, Oscar's system generally produces slow and steady wins, but with occasional deep troughs that eat in to (and beyond) your winnings.

If the results of the simulations seem to be a bit too promising at first, keep simulating until you encounter one of the trademark horrifying downswings.

Algorithm / Code

Here's some working Ruby code that shows how Oscar's system works from a programming perspective. The code stops when you hit the target of one-unit profit (as opposed to repeating the system over a given number of spins).

# Settings
unit = 1
balance = 100

# Set the initial bet size
bet = unit

# Set the target as a one-unit win
target = balance + unit

# Repeat until we hit our target
i = 0
while balance < target
  # Increment spin counter
  i = i + 1

  # Spin the roulette wheel
  result = rand(0..36)

  # Check if the result is a win
  win = (result >= 19) # using the high numbers as the even-money wager

  # Print bet size and result
  print "Spin #{i}: bet=#{bet} #{win ? "(win)" : "(lose)"}, "

  if win
    # Update balance
    balance = balance + bet

    # Increase bet by one unit
    bet = bet + unit

    # If winning again with this size bet would take us above our target
    if (balance + bet) > target
      # Adjust bet down so it will produce a total profit more one unit
      bet = target - balance
    # Update balance
    balance = balance - bet

  # Print new balance
  print "balance=#{balance}\n"

Who invented Oscar's system?

The system was first outlined by Allan N. Wilson in his book The Casino Gambler's Guide (1965):

It was shown to me by a dice player who had used it consistently over a period of several years to win the price of many weekend trips to Las Vegas.

— Allan N. Wilson

So I'm assuming this person was named Oscar, and Allan Wilson named the system after them in their honor.

Tip: This system is also commonly known as "Oscar's Grind", which is the name given to the system by Christopher Pawlicki in his book Get The Edge At Roulette (2001).

What's the logic behind the system?

The goal of the system is to repeatedly grind out small one-unit wins until you achieve your target win amount.

The system is based on the fact that there is a high probability of a small win, and the probability of going broke is slim, so you should be able to slowly and cautiously win your way to a profit. In fact, strict adherence to limiting yourself to one-unit wins is all part of the approach:

In fact, the originator claims that it is the willingness to be content with a profit of one unit , where the greedy player might try for more, that is the saving feature of this system.

— Allan N. Wilson

This sentiment of being content with small wins as the key to success is shared with other famous roulette players:

If you gamble in small doses every day, it is impossible not to win.

Fyodor Dostoevsky

So the system seems to be based on the belief that you can avoid going broke by limiting your greed and being content with small but repeated wins. Or in other words, it's based on a superstitious belief that the roulette wheel is out to "get" anyone who loses their cool.

Why increase your bet when you're winning?

There is nothing in the book that explains why Oscar's system is designed the way it is, so I'm not exactly sure what the logic is behind increasing your bets when you're winning (whereas most systems are negative progression, where you increase your bets when you losing).

Chart showing bet size and corresponding balance when using Oscar's system

Typical example of using Oscar's system. You only increase your bet size after experiencing a win.

My guess is that a win after a series of losses signifies a "turning of the tide", and so by increasing your bet at this point you're betting in to a positive change in fortune and looking to maximize your returns from it.

The final adjustments of aiming for the one-unit win are then in place to meter your enthusiasm as you finally approach a profit.

Why doesn't it work?

Because you'll lose a tremendous amount when you hit an unlucky streak, and the amount you have won up to that point will not cover these rare but large losses.

The reason people use the system is because it appears to work in the short-run, but that's only because they have gotten lucky and are yet to experience the mammoth downswings that come with using Oscar's system:

I was amazed that in the long time he worked it, there was never a session of losses rough enough to discourage him from pulling each sequence through to a successful conclusion.

He was very lucky indeed.

— Allan N. Wilson

In other words, the premise for using the system is thinking that "it's never going to happen to me".

And it usually doesn't... until it does.

How does Oscar's system compare to other systems?

Oscar's system is basically a reverse of the d'Alembert system, except that you do not change your bet size when you're losing.

It's also somewhat similar to the Paroli system because it's one of the few positive progression systems (where you increase the size of your bets when you're winning). However, unlike the Paroli which maximizes wins from lucky streaks (but otherwise accepts that you're generally going to lose), Oscar's system uses positive progression to try and guarantee a win.


Oscar's system is a simple betting system that tries to achieve a profit by aiming for small but repeated wins at the roulette table.

However, like all systems it is susceptible to the occasional devastating loss that will wipe out all of the previous small wins you might have achieved. So whilst you may win a small amount a majority of the time, it will not be enough to cover the rare but catastrophic losses that are always lurking around the corner.

For that reason, I would avoid using Oscar's system. It doesn't achieve it's goal of producing a slow but guaranteed profit, and all you're left with is a particularly unexciting system. What's worse is the fact that the regular small wins might lead you to believe that the system is working, only for it all to be stripped away unceremoniously.

It is essential to grasp the fact that although the probability of a single disastrous event may appear remotely small, the cumulative effect with many sequences leads to nearly certain disaster.

— Allan N. Wilson

So if you're going to use a system, use it because you think it's fun, and not because it has misled you in to thinking that it could work. Oscar's system is unfortunately the latter.

If nothing else, Oscar's system is just another reminder that all seemingly successful roulette systems are doomed to failure if you play them for long enough.