Glossary
30 terms used on Wheel Theory, each linked to the pages that use it.
D
- Distinct pockets
The actual union of outcomes a selection covers. Two overlapping descriptions do not create two separate copies of the same pocket.
Used in: Online roulette rules: what changes the probability and payout?
E
- Edge
The gap between the payout and the true odds, stated as the share of each stake the bet costs in expectation.
Used in: Best free roulette payout chart: every bet’s edge, computed from the wheel
- En prison
A zero rule that holds an even-money stake for the next spin; a matching result returns it, an opposing result loses it.
Used in: La partage and en prison settle the same zero differently
- Even-money wager
The wager whose zero treatment varies between rule sets: at double-zero tables either half or all of the stake can be lost under the stated option.
Used in: Online roulette rules: what changes the probability and payout?
- Expectation
A weighted mathematical average. It does not say that a one-unit wager literally loses 0.027027 units when settled; in the specified one-number model it either loses one unit or makes 35 units of profit.
Used in: Online roulette rules: what changes the probability and payout?
- Expected cost
A rate per pound staked, not a forecast of an evening. On a 37-pocket wheel it is 2.70% of everything staked; on 38 pockets it is 5.26%.
- Expected loss
The average net change per wager under the stated model; not a deduction charged after every spin.
Used in: La partage and en prison settle the same zero differently, Overlapping roulette bets need a whole-layout payout calculation
- Expected value
The average result of one bet across many repeats of it, written here as pounds lost per £10 staked.
Used in: The zero belongs in the calculation
F
- Full-loss zero rule
The ordinary rule under which every position loses when zero lands, with no half-refund or held stake.
Used in: Overlapping roulette bets need a whole-layout payout calculation
G
- Gross return
The money that comes back on a winning position, including its stake.
Used in: Overlapping roulette bets need a whole-layout payout calculation
H
- Half back on zero (la partage)
A rule on some tables that returns half of an even-money stake when the zero comes up, halving that bet’s edge only.
Used in: Best free roulette payout chart: every bet’s edge, computed from the wheel
- Hold
Money the table keeps pending under a prison rule; neither returned nor yet lost.
Used in: La partage and en prison settle the same zero differently
- House edge
The Gambling Commission's guide defines it as the percentage a casino would expect to keep, on average, from each hand or spin, given normal patterns of play.
Used in: The zero belongs in the calculation, Streaks and roulette strategies: are there any that work better on European wheels than American ones?, Best free roulette payout chart: every bet’s edge, computed from the wheel
I
- Independent draw
Each spin starts from the same pockets, whatever the last one did. Of random gaming machines the Commission writes that the odds in the current game are not affected by wins or losses in previous games.
L
- La partage
A roulette rule under which half of an even-money stake is returned when the ball lands in zero. It is not in the Massachusetts table quoted here.
Used in: The zero belongs in the calculation, La partage and en prison settle the same zero differently
N
- Named in advance
A run whose spins you choose before they are spun. Only a run named this way has the probability the multiplication gives.
- Net profit
All gross returns for the round minus everything staked on that round.
Used in: Overlapping roulette bets need a whole-layout payout calculation
- Net result
The difference between money returned and money staked in the calculation being described.
Used in: Online roulette rules: what changes the probability and payout?, Overlapping roulette bets need a whole-layout payout calculation
P
One numbered compartment on the wheel. The rules call it a compartment; a single-zero wheel has 37 of them.
Used in: The zero belongs in the calculation
- Pocket count
The number of compartments on the wheel: 37 with one zero, 38 with a zero and a double zero. It fixes the rate on every standard bet.
R
- Return to player
The Commission describes it as part of the money paid to play a machine that is then given back to the player as prizes, averaged over a significant number of plays. It is the same idea as the edge, counted from the other end.
Used in: Streaks and roulette strategies: are there any that work better on European wheels than American ones?, The zero belongs in the calculation
- Return to player (RTP)
The part of the money paid in that is given back as prizes, measured as an average over a large number of plays.
Used in: The zero belongs in the calculation
- RTS
The Gambling Commission’s remote gambling and software technical standards. RTS 3 is the one covering rules, game descriptions and the likelihood of winning.
Used in: The zero belongs in the calculation, Best free roulette payout chart: every bet’s edge, computed from the wheel, La partage and en prison settle the same zero differently
S
- Selected after the fact
A run picked out of a results panel because it was already visible. The same multiplication does not describe it.
- Self-exclusion
A formal agreement with an operator or a scheme not to gamble for a set period. The Commission calls it a tool used by those who have recognised that their gambling is harmful to them.
- Settlement
The instruction that decides what happens to a stake after a result: returned, lost, or held.
Used in: La partage and en prison settle the same zero differently, Online roulette rules: what changes the probability and payout?, Overlapping roulette bets need a whole-layout payout calculation
- Stake
The amount put at risk in a particular bet.
Used in: The zero belongs in the calculation, Streaks and roulette strategies: are there any that work better on European wheels than American ones?, Best free roulette payout chart: every bet’s edge, computed from the wheel, La partage and en prison settle the same zero differently
- Straight-up wager
A wager on one specified number. In the Massachusetts comparative record it pays 35 to 1 profit.
Used in: Online roulette rules: what changes the probability and payout?
T
- True odds
The chance of a bet winning stated against it: one pocket in 37 is 36 to 1 against.
Used in: Best free roulette payout chart: every bet’s edge, computed from the wheel
U
- Union of winning numbers
The set of pockets covered by at least one selection, with a shared pocket counted once.
Used in: Overlapping roulette bets need a whole-layout payout calculation