If you missed it, See Part 1 here. As a recap, most people believe roulette is the most random and unbeatable game in the casino. The truth is it’s in fact by far the game that’s most vulnerable to professional players. This is because the winning number is determined by a mechanical device which is never physically flawless. Even if wheels were flawless, there are still various ways to predict spins. It is far more difficult to design a wheel with truly unpredictable spins, than it is to achieve sufficiently accurate predictions.
Roulette wheel designers know this, which is why they introduce various technology to make spins less predictable. And casinos know this, which is why surveillance staff get nervous when you behave in ways consistent with a professional roulette player.
Remember, what casinos do gives clues to what they are afraid of, and how roulette is being beaten.
This part explains more about what casinos and wheel designers do to make wheels less predictable.
If the wheel isn’t on a perfectly level surface, the ball tends to fall from the ball track more often on particular spots. This leads to the ball hitting specific diamonds more than others. The effect is known as “dominant diamonds”. You can very easily see this by observing 10 or so spins of any wheel. Almost every wheel will at the very least have specific areas where the ball doesn’t fall from. This isn’t random, and can therefore contribute to a player’s edge.
Normally the casino staff use a leveling tool similar to what bricklayers use, with a spirit level. The most common such tool is shown below:
One problem with this is it only takes a slight error for there to be significant dominant diamonds. Having one side of the wheel even 1mm higher than the other can produce a significant dominant diamond. Having 0mm difference is not realistically possible.
To take “human error” out of the equation, one of the wheel manufacturers created “auto-leveling” equipment. Basically it tracks where the ball falls from the ball track, and automatically adjusts the “tilt” of the wheel so the diamonds are hit more evenly.
It sounds like the casino’s problem is solved, but in fact they’ve created a potentially bigger problem. This is because “dominant diamonds” are more often caused by ball track imperfections, rather than “wheel tilt”. The imperfections are often impossible to see with the naked eye. So if the wheel is placed on a tilt in attempt to reduce “diamond dominance”, here’s how the casino shoots itself in the foot:
- At the end of the spin when the ball hits the rotor, one half of the rotor will be slightly LOWER than the other. This means the ball is more likely to stop in the lower region. Think of it like a slight ditch. All players need to do to take advantage of this is correlate winning numbers to where the ball first impacts the rotor. The effect is similar to roulette wheel bias, except the wheel’s rotor could be physically flawless and still give professional players an edge.
- The casino may have reduced “diamond dominance”. They will see the ball appears to hit each diamond a more even amount of times. So when professional players are exploiting the flaw, casino staff will be left scratching their heads as to how the players are winning. That’s assuming they even notice the player covertly winning.
- When the ball falls at the “higher side” of the wheel, the ball’s trajectory (angle) when it impacts the rotor will be steeper. This makes the ball bounce less (on average). The overall effect is the ball will bounce more predictably on many spins, which is exactly what dominant diamonds causes in the first place.
So auto-leveling equipment sounds like a good idea for casinos, but the spins are still “less than random”, and the cause is much more difficult for casino staff to identify. In fact, even the best trained staff usually wouldn’t have any idea, because they would only be aware of the threat of dominant diamonds. Although if you check your local casino’s wheels, you’ll see most of them have significant dominant diamonds anyway. So do you still think casino surveillance staff are so highly skilled and trained that it makes winning too difficult? The roulette wheel is far from an unbeatable device – actually it’s riddled with problems.
Forbidding Late Bets
If you’re at least vaguely aware of how visual ballistics or roulette computers work, you’d know they benefit from dominant diamonds. Basically they determine where the ball will first hit the rotor, and numerous spins can be tested to determine how far the ball bounces. And with significant dominant diamonds, you already know where the ball will mostly fall. So then achieving sufficiently accurate predictions is more about calculating what number will be under the dominant diamonds when the ball falls. It’s actually not at all difficult. Again keep in mind you don’t need perfect accuracy. The house edge is only small, so you only need to have accuracy slightly better than random.
But it requires players to make predictions a few seconds after the ball is released, then quickly place late bets while the wheel is still spinning.
So if beating roulette with late bets is so easy, then why do casinos allow late bets? The answer is simply because most players have no idea what they’re doing. Most players have systems that make outside bets like odds, evens, dozens etc. Most players aren’t even considering what’s actually happening on the wheel, which is the only place you should be looking.
However, when a professional player joins the table and starts winning too much with late bets, the dealer is supposed to be instructed to close bets earlier and earlier, until the professional player loses or leaves. This would make visual ballistics and roulette computers useless. A professional player knows how to win discretely, so can comfortably make a $5,000 profit look like luck.
Furthermore, because casinos maximize their earnings from allowing late bets, they aren’t too concerned with the comparatively rare professional player. After all, the professional player might win $5,000 from late bets. But the 99.99% of players made the casino $250,000 from late bets that lost.
As with part 1, none of the above makes roulette unbeatable. That’s not to say there aren’t steps can’t take to make winning harder, or even impossible. But casinos don’t do this because it means they’ll lose revenue in other ways, and their combined revenue will be lower.