What casino app has the best odds: the short version
The straight answer to "What casino app has the best odds?" is found at the wheel. Roulette looks like pure chance, and it is, but the rules still decide how much any bet costs. A European wheel has one green zero, an American wheel adds a second, and French tables add rules that return half of some losing bets. Knowing which wheel is in play, what each bet pays and what the zero takes is most of what there is to know about playing roulette sensibly.
The best odds in roulette are on a single zero wheel, and better still under French rules. European roulette keeps an edge of about 2.7 percent; French tables add la partage, which gives back half the stake on even money bets whenever zero lands and so halves that edge on those bets. French layouts also take call bets placed by name, such as the neighbours bet on a number and the two either side of it on the wheel. Knowing how to play French roulette mostly means knowing those extra rules.
Licensed roulette wheels are not rigged: they are tested and balanced, and casinos log results so that a biased wheel would show up in the numbers. Balls are not weighted; they are made to a standard size and material, and a worn wheel is replaced rather than exploited. Roulette machines use a random number generator that is checked in the same way and cannot be fixed by the casino. Under licensing regulations there are no illegal bets on the layout itself, although devices that try to predict the ball are banned almost everywhere.
Quick answers
Do roulette betting systems improve the odds?
Systems only alter the size and rhythm of stakes; every spin is independent and every bet keeps the same edge, so no pattern predicts the next number.
What are the odds of the ball landing on green?
On a single zero wheel the chance is one in thirty seven, and on a double zero wheel one in thirty eight for each green pocket.
How are roulette wheels and balls kept fair?
Licensed wheels are tested and balanced, results are logged so bias would show, balls are made to a standard, and electronic machines use checked random number generators.
Why does the speed of play matter at roulette?
Each spin charges the same share of the stake, so a live table at about forty spins an hour drains a budget far slower than a fast online game.
What are neighbours bets and other call bets?
Call bets are placed by name on French layouts; the neighbours bet covers a chosen number plus the two pockets either side of it on the wheel.
What is the only effective roulette strategy?
Choosing a single zero wheel, holding to a fixed budget and knowing when to stop is the only approach that works, since the edge stays constant.