Testing the 666 Roulette System
Did you know that roulette has been referred to as the game of the devil? No, this is not because many players have a difficult time making money at it, but because the sum of all numbers on the roulette wheel adds up to 666. This brings us to the 666 system, which is often considered a highrisk strategy.
Let's examine how it works and determine just how risky the 666 system is and if its a viable strategy to use to make profit at roulette.
How Does The 666 System Work?
The 666 system is a straightforward, nonprogressive method that involves placing multiple bets at once. This is how it's done:
 Place a 36 unit bet on Red
 Stake 4 units on each of the following splits: 0+2, 8+11, 10+13, 17+20, 26+29, and 28+31. Note that all of these split roulette bets only cover black numbers.
 Stake 2 units each on any three uncovered black numbers.
The first thing to note here is that the 666 strategy is exclusively designed for roulette. The system covers 33 of the 37 fields on a European roulette board, which means that you have 89.19% chances of winning. The total stake is 66 units, and there are four possible outcomes:
 If one of the splits wins, the player wins a total profit of 6 units. There’s a 32.43% chance of this happening.
 If one of the straightup bets wins, the player wins a total profit of 6 unit, and the chance of this happening are 8.11%.
 If Red wins, the player wins a profit of 6 units. There’s a chance of 48.65% for this to happen.
 The darkest scenario is for none of the bets to win. The chances of this happening is 10.81%, and the player loses 66 units.
By using the 666 strategy, a player must win 11 times to compensate for a single loss. Let’s try the 666 strategy in practice.

Spin 1
We place the 66 units bet on a European roulette table. The ball hits the 10 slot, which means that we win one of the splits and make a profit of 6 units.

Spin 2
We place the 66 units bet and the ball ends on 35, which means that we win a straightup bet and make a profit of 6 untis again.

Spin 3
The ball lands on 19 Red, and we win on our Red bet  which means another 6 units in profit

Spin 4
The ball lands on 4 Black, and we lose the bet. We lose 66 units, and we’re down 48 units in total.

Spin 5
The ball lands on 7 Red, which means that we win another 6 units, and we’re now down 42 units.
Putting the 666 System to a Test
To see how the 666 strategy performs in a reallife scenario, we decided to create an experiment in a random simulation based on the factual percentages of this strategy. To test the longterm successfullness of the strategy, we used four players  each one with a starting bankroll of AU$1,000 over 1,000 rounds. Mathematically, we expect to win 892 out of 1000 rounds, which adds up to a total gain of 5,352 units for the wins. The projected loss is 7,128 units for the 108 expected losses  which means that we expect to experience a ‘hole’ of 1,776 units over the course of 1,000 rounds. Let’s see what happened.
As you can see from the graph, three of the four players experienced a sharp bankroll decrease almost immediately. Player 1, Player 2, and Player 3 would have never even made it to the 1000th turn if this was a reallife scenario, since they busted out their initial bankroll soon after the 400th turn.
Player 4 had better luck than the rest and managed to ‘zero out’ his bankroll by the 800th spin (although they also fell below zero at one point). However, even Player 4 didn’t end the session in profit. After zeroing out, they finished with around AU$800, which is still AU$200 below their initial bankroll.
Judging by our test, it’s clear that the 666 strategy is not a good choice as a longterm roulette strategy. That doesn’t mean that the strategy is useless, however. Based on our test, all players had made profit during the first 20 moves, which means that the strategy can be useful in the short term.
Drawbacks Of Using The 666 System
The 666 strategy looks like a viable option at first glance. There’s an 89.19% chance of winning after all, and many people rely on that percentage. However, the problem is that it takes 11 wins in a row to make up for each loss. Sure, if you’re lucky, you might hit more than 20 wins in a row (Player 4 in our test had multiple 20+ wins in a row). Unfortunately, the maths don’t support the 666 strategy as being a viable longterm roulette system. Although it’s likely to recover from a single loss, experiencing two or three losses in a row can seriously hurt your bankroll and make it almost impossible to bounce back.
Another disadvantage of this strategy is the fact that you have to wager 66 units each time, which requires a large bankroll.
Conclusion
The 666 strategy is unedniably one of the most popular roulette systems  but we believe it’s mostly due to the name and online popularity rather than its effectiveness.
We put the strategy to a test with four players and 1,000 rounds, and it ended in disaster for every one of them. Notably, however, they all had short winning streaks in the beginning, which means that the strategy can be a good option for short runs. As with all roulette strategies, though, it involves luck  and a great portion of it.
In our opinion, the 666 roulette strategy can be combined with the d’Alembert system by increasing the bets by one unit when you lose, and decreasing them when you win. However, we think that there are more effective and less risky strategies than the 666 system out there.