With most casino games, preparation for play is merely a matter of randomizing cards or shaking up dice. In roulette the process is more complicated, involving momentum, gravity, and Newton’s laws of motion. It could be one reason engineers seem to be drawn to the game and why some try to sell betting systems based on the physics of play.

For some reason mathematicians and physicists seem drawn to gambling and games of chance. Perhaps the most famous story is about mathematician Ed Thorpe who invented a betting strategy for blackjack based on theories of probability called “card counting” that has forever changed the way the game is played in casinos. If a math whiz can conquer blackjack, why can’t a physicist figure out roulette?

Newtonian Mechanics

What one finds when looking into the physics of roulette is that it gets very complicated very quickly. Looking up an article on the subject almost immediately leads one to reading equations with funny symbols and constants with names such as “aerodynamic drag coefficient,” “gravitational acceleration,” and “stator inclination.” In fact, equations exist to explain every aspect of the spinning roulette ball and wheel including the effects of gravitation on the spinning ball, air resistance, and surface friction.

All of these factors combine into a mathematical analysis of how long the ball will spin, when it will drop out of rotation, and what slot on the wheel in which it eventually will land. This last part is what is of interest to roulette players, but has little practical value since plugging numbers into the equations and adjusting the variables is an impossible task while play is ongoing.

Cheating

The equations do have practical implications when there is doubt that all is on the up and up. If the roulette wheel is not perfectly balanced, the physics shows that it will affect the outcomes of spins. One well-known paper on the subject explains how an angle of as little as 0.2 degrees from level can create a “forbidden zone” from about one quarter to one third of the table, meaning the ball will never land in one of those slots.

Arrangement of Numbers

There also is some physics involved with the arrangement of the numbers on the wheel. Like a dart board, the numbers are not randomly placed, instead are alternated in ways to separate low numbers from high and even numbers from odd. The goal here is to even out the odds that the ball will enter the spinning wheel with a tendency to favor certain betting combinations over others.