Snake and Column bets

Players in roulette lose because the ball landed on a number they did not bet on. Some roulette betting systems are based on minimizing the amount of times this happens: they aim to spread the betted chips so that most numbers either generate profit or minimize losses.

Common ways to do this combine inside and outside bets, betting on singles, splits, rows, etc. and compensating for the numbers left open with an even money outside bet (red-black, high-low, even-odd), or a column or dozen.

This is a type of system that determines types of bets and nothing else, and can be easily combined with a system that controls bet size (Labouchère, D'Alembert, Martingale, etc.) to further optimize winnings or keep losses to a minimum. Do be aware that these spreading type bets require a lot of chips to bet at once, and using a progressive system can increase losses extremely rapidly.
The following are two of the most popular roulette systems that bet on many different numbers.

1. Snakes on roulette colours

Looking at the betting table, you see the red and black numbers are distributed randomly over the three columns. This system bets on a snake of one colour of singles zig-zagging over the table, and bets the same amount on the opposite colour from that of the snake. This complements the single number bets (which will rarely win) with an even money bet, to cover most of the board.

How a snake bet works

The most obvious "snake" on the board is the red one. It consists of the numbers 1-5-9-12-14-16-19-23-27-30-32-34, a total of 12 singles. The full snake bet is made by betting on these twelve, and betting the same amount (12 chips) on black. We now have 24 chips wagered, lets see how that can go:

  • The red numbers 3-7-18-21-25-36 are not covered by our bet and an outcome of any of these six numbers will make us lose all our 24 chips. The chances of this happening are 6 / 37 = 16%.
  • 0 will actually cause a smaller loss than the open red numbers, if the "En Prison" rule is in effect: this will give us a 18 / 37 chance to regain our 12 chips bet on black on the next spin. That means there is a 48.6% chance after a spin of 0 to come away with only half the losses.
  • If the result is a black number, we will have lost 12 and won 12 chips, meaning no losses whatsoever. There is a 48.6% chance of this happening.
  • If any numbers of the snake hit (a chance of 12 / 37 = 32.4%) we lose 23 chips, but gain 35, for a total gain of 12 chips.

The chances of coming away with a profit are almost a third, and there is an 81% chance not to lose any money. However, the expected profit over the long term is -0.5 chip per bet, which means the house edge is 2.0%.

Other snakes

The most obvious variant is the black snake: betting on 12 different black numbers and balancing this bet out with 12 chips on red. Also, a player could bet on any twelve numbers of the same colour and bet the same amount on the even odds bet of the other. The odds are exactly the same as in the above example of the red snake.

A "risky snake bet" would be to simply bet on twelve the same coloured numbers and not bet against it with an even money bet on the other colour. So a player would bet the red snake, but bet nothing on black. The odds of not losing are a lot worse: only 32%, but the overall expected loss is only 0.32 chips per bet, less than the regular snake bet. The big disadvantage here is that this will increase the speed at which your losses increase, shortening your playtime with a set bankroll.

Another variant is to bet on splits instead of singles, halving the amount wagered, but also the amount won.

2. The First and Third Column

You can see on the roulette table that there are only four red squares in the middle column, and the rest of the numbers are black. The First and Third Column system attempts to exploit this by making the following bet: 2 chips on the first column, 2 chips on the third, and 2 chips on black. Only those four reds in the second column are left open. A few things can happen, depending on where the ball lands:

  • Red
    • First or third column: We have bet on this column, but not this colour. We lose and win nothing. This happens about 38% of the time.
    • Second column: This number is open… We lose 6 chips. The chances of this happening are only 13%.
  • Black
    • Second column: We got the column wrong (loss of 4), but the colour right to compensate (win 2), so we effectively lose 2 chips. This occurs 21% of the time.
    • First or third column: Now we win! We lose the bet from the other column (lose 2), but are right on the column (win 4) and the colour (win 2), so we gain 4 chips. The balls lands here about 28% of the time.
  • Zero
    Now we lose both column bets (-4), but our bet on black is pushed to the next spin when the En Prison rule applies, in which case we have a 18 in 37 chance of not losing that bet if black hits on the next spin.

Using this system we lose a bit more often than when betting a snake, but we lose little every time. In fact, the long term average profit per bet is only -0.14, which corresponds to a house edge of 2.5%.

Similarly, as with the red and black snakes, this system works just as well when only the four black numbers in the third column are left open. This "red version" of the double column system works by betting two chips on the first and second column, and betting two on red. The odds of winning and losing are, of course, the same as above.