Atlassino Academy · Slots · Lesson 2 of 10
Return to player: twins that aren't
Two machines can carry the same glass, land a prize just as often, and still give back different shares of everything staked — and the share is printed on neither of them.
Lesson 2 of the slots track. One number, fixed before a machine ever reaches the floor, and how little an evening at that machine has to say about it.
Two machines stand side by side with the same picture on the glass. One has been paying all evening and one has not. Which one do you sit at?
The short answer
Nothing you can see decides it. A return figure counts what a game gives back across its whole working life, and a thousand spins of that life is a rounding error: stand a machine that gives back 85% beside one that gives back 92%, run 1,000 spins on each, and the poorer of the two machines finishes level with the other machine or ahead of it 39 times in a hundred. Neither figure is printed anywhere on the cabinet, and the two machines can match down to how often they land a prize.
- The cabinet, and how old it is
- How bright the screen is
- How often the machine lands a prize
- What the machine paid ten minutes ago
- The figure published for the province
- What each symbol pays, printed on the paytable where anyone can read it
- How many stops on the reel carry each symbol, printed nowhere
Leoformer dealer · rules and maths
What is attached to it is a number set in a factory and checked before the machine came through the door. So: what that number counts, how long it takes to show itself, and what two machines wearing the same picture can be hiding from each other.
What the figure counts
Return to player is a share of the bets, not a share of what is in your pocket. Money goes in, some of it comes back, the same money goes in again, and it keeps going in until nothing is left — so ten bets in front of a machine buy far more than ten spins, and every one of those spins counts in the figure. That is turnover.
Ten bets, one bet a spin, nothing added and nothing taken out. The bars are the same ten bets on two machines, and the only thing that differs between the two bars is the share the machine gives back: what a machine keeps on every spin is what empties the ten bets.
The rate is fixed and the spin is not. Every prize is drawn at random; what was programmed is how often each prize comes up, and those chances were set according to the share the game is built to give back. So 85% describes no evening you will ever sit through, and was never meant to: it describes the working life of the machine — every spin from the day it is switched on to the day it is carted out.
How long it takes to show
A player has one instrument and it is a blunt one: money in against money out. Point it at a machine that gives back 85% and at one that gives back 92%, and it reads like this.
| After | The 85% machine has shown | The 92% machine has shown |
|---|---|---|
| 100 spins | 30% to 175% | 30% to 180% |
| 1,000 spins | 57% to 135% | 64% to 143% |
| 10,000 spins | 73% to 99% | 80% to 106% |
| 1,000,000 spins | 84% to 86% | 91% to 93% |
Nine runs in ten land inside the range shown. Only at 1,000,000 spins do the two ranges come apart, and by then ninety-nine runs in a hundred on the 85% machine sit within 2.1 points of its figure.
Now stand the two machines side by side, run the same number of spins on each, and pick the machine whose counter is higher. The machine that gives back the smaller share finishes level with the other machine or ahead of it this often:
| After | The 85% machine is level or ahead |
|---|---|
| 100 spins | 47 in 100 |
| 1,000 spins | 39 in 100 |
| 10,000 spins | 27 in 100 |
| 100,000 spins | 3 in 100 |
Two machines, one difference
Both machines carry the same glass and the same paytable. Both land a prize on 8.8% of spins. On both, the largest prize sits on 1 in 5,000 spins. Behind each is a reel of ten thousand stops, every stop as likely as any other. Both machines are made up: no manufacturer we could read publishes a real reel strip.
| Symbol | The 85% machine | The 92% machine |
|---|---|---|
| pays 500 times the bet | 2 | 2 |
| pays 100 times | 8 | 8 |
| pays 25 times | 60 | 95 |
| pays 10 times | 230 | 230 |
| pays 5 times | 580 | 545 |
| pays nothing | 9,120 | 9,120 |
Only two rows differ, and in opposite directions; every other row is identical.
- 35 stops come off the symbol that pays five times the bet and go on to the symbol that pays twenty-five times the bet.
- Each stop that moved pays 20 bets more than it paid before, every time the reel lands on it.
- Over ten thousand spins the stops that moved bring back 700 bets more than they did.
- Ten thousand spins are ten thousand bets staked, so 700 bets more is 7 points more: 85% becomes 92%.
Two machines can look identical and carry different figures. How a reel of ten thousand stops is mapped to the three or five you watch come round is a lesson of its own; what it does to an evening — the same share arriving in trickles or in one thunderclap — is the next one.
What each province puts in writing
| Province | What is in writing | Published by |
|---|---|---|
| Ontario | 85% — the least any game may return, at every bet the game offers | AGCO |
| B.C. | 92% — the average return across the province’s casinos | BCLC |
| Quebec | 92% — the theoretical return on average, with about 8% of everything wagered going to the house | Loto-Québec |
| Manitoba | no figure of its own: 92% turns up as a worked example of what a payout percentage means | Manitoba Liquor & Lotteries |
A floor and an average are different animals, and neither is a number about the machine in front of you.
What a room owes the people in it is information about a game’s chances and what it pays, clearly stated and made available. The standard names three things, and any one of the three satisfies it.
- The chancesHow likely each prize is
- The payout oddsWhat each prize pays when it arrives
- The returnsThe share that comes back
What differs online in Canada
The figure itself does not change when the game moves to a screen: it is still worked out before anyone plays, and it still describes a whole working life rather than your session. What changes is who owes whom a number.
On the floor, no game may give back less than 85%, and no rule puts its own figure in front of the player. On a province’s regulated sites it is the other way round: no minimum of that kind, but the operator’s advantage on each wager is written into the game’s own specification. Before a bet the player must get the chances, the payout odds or the returns — one of three.
Neither side simply tells you more than the other, and neither standard is the whole story: both of them say what a game must do before anyone plays it, and neither of them says what any one machine or any one game has actually given back.
Practice: which machine, and how long
Nothing spins here. Level 1 sets two machines side by side and lists what differs between them line by line, and you say whether any of those differences moves the share that comes back. The answers are not all the same: most of the differences move nothing at all, one of them is printed on the paytable where anyone can read it, and two of them lie on a reel nobody at the machine can see. Level 2 shows the counters after a finished run and asks what a run that long settles. Level 3 takes five things a return figure is read as promising.
Only level 1 is scored: every square on the strip below is one of its questions, and they are all there from the start. When they are full, level 2 begins by itself. Levels 2 and 3 have no squares and no score — there one answer fits every question of its kind, and a mark out of ten would be measuring patience.
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Level 1 · Which machine
Same maker, two cabinets
Two machines, line by line
| Machine A | Machine B | |
|---|---|---|
| Picture on the glass | the same game | the same game |
| Lands a prize on | 8.8% of spins | 8.8% of spins |
| Largest prize | on 1 in 5,000 spins | on 1 in 5,000 spins |
| Cabinet | this year | eight years old |
| Screen | bright | dim |
Which of the two machines gives back a bigger share of everything staked?
The answer: Nothing in this list changes the share
Two machines can look identical and still give back different shares, and two machines that look nothing alike can give back the same share. A cabinet is not evidence either way.
Level 2 · How long it takes
Two machines: one gives back 85%, one gives back 92% · 50 spins each · one bet a spin
50 spins on each, side by side
Machine A
staked50 bets
came back35 bets
70%
Machine B
staked50 bets
came back40 bets
80%
After 50 spins each, how far can the higher of the two counters be trusted?
The answer: Not at all: right about half the time
Over 50 spins the machine that gives back 85% still finishes level with the machine that gives back 92% or ahead of it 49 times in a hundred, so picking by the counters gets it right 51% of the time.
Level 3 · What it will not do
A figure and an evening
At the machine
This machine gives back 92%, so nine evenings in ten I should come out somewhere near level.
How far does the claim follow?
The answer: The claim does not follow
An evening is not a short version of a machine’s working life. One evening is a single draw out of a very wide range of possible evenings, and that range only narrows after tens of thousands of spins.
Every counter in the practice table is a real draw from the outcome table of that machine, made when the page is built; the shares beside it come from the exact distribution rather than from more draws.
How the practice table works
Where the counters come from. Each counter on level 2 is a real draw from the outcome table of that machine, made when the page is built, so the picture and the figures can never disagree. Nothing is drawn again until it comes out a particular way: the question there is how long a run has to be, not who happens to be in front.
The shares beside them are not more draws. They are the exact distribution of that many spins, worked out by the same code as the tables above, because a hundred draws would land near the true figure rather than on it.
What is scored and what is not. Level 1 has a rule to learn and it is graded. Levels 2 and 3 are a reference you page through.
Check yourself
Mayaformer floor supervisor · manners, money and breaks
Five quick ones. Pick an answer, then check it. No timer, no points: just whether it stuck.
Where to look this up
19+ (18+ in AB, MB, QC) · Play responsibly · helplines by province are at the end of this page
Mayaformer floor supervisor · manners, money and breaks
Here is the practical half. The figure is not something you can look up for the machine you are at, and the counter on it is not something you can read. Which leaves two numbers in the room that are yours: how long you meant to stay, and how much you meant to spend. Decide both of those before you sit down, and do not let the last hour move either one.
If the money on the machine starts to feel like money you need, stop there and call one of the lines below. That is what they are for.
If it stops being fun
If gambling stops being entertainment, help is available. 19+ in most of Canada; 18+ in Alberta, Manitoba and Quebec. More on responsible gaming.
Further reading
The documents this track is written from, in full.
- Minimum Technical Standards for Gaming, 11: Game Behaviour · Alcohol and Gaming Commission of OntarioWhat a slot machine in a room is allowed to do, clause by clause: the payout floor, the reel strip, the odds on the largest prize and the ten games of history every machine can show you.
- How to play slots · Ontario Lottery and Gaming Corporation (PlaySmart)An operator walking through the arithmetic of one spin, with its own worked example: nine lines on a nickel machine, and what one press of it takes.
- How to play slots · British Columbia Lottery Corporation (Casinos BC)Reels, lines and the province’s average return, in the words of the corporation that runs the rooms.
- Understanding chance: slot machines · Loto-Québec (Wise Play)The near miss, volatility and the illusion of control, named and explained by a provincial operator rather than by us.
- Informed Gambling: slots and VLTs · Manitoba Liquor & LotteriesA short brochure on what a payout percentage is and is not, and why two machines with the same one can empty a wallet at different speeds.
- Registrar's Standards for Internet Gaming: game design and features · Alcohol and Gaming Commission of OntarioThe same machine on a screen: what a regulated site in Ontario may not do with the picture after the outcome has been drawn.
How it’s worked out
Sources, numbers and hosts
Where this happens. Every machine on this page is a cabinet standing in a room you can walk into. The same game also runs on a province’s own regulated site, under a different book of rules, and what that book asks for instead of a minimum is the one thing about screens this page takes on.
Sources. Every figure attributed to a province is quoted where it is used, with the publisher, the document and the date it was read behind the button beside it. No publisher we could read gives a figure for any one machine on any one floor, and this page does not supply one either.
The two machines. They are ours, and they are not real games: each is a reel of ten thousand stops, every stop as likely as any other, and the two differ only in how many of those stops carry the symbol that pays twenty-five times the bet and how many carry the symbol that pays five times. No manufacturer we could read publishes a real reel strip, and inventing a real machine’s would be worse than teaching on a declared toy. Both shares — 85% and 92% — are figures a province has actually published, one as a floor and one as an average.
Numbers. Worked out when the page is built. What a machine gives back is the sum of its stops times their pays, over ten thousand; what a run of that machine shows is the exact distribution of that many spins, not a simulation of it. Every figure counts bets, never money: a flat bet of any size gives the same tables, and what an evening costs in money belongs to the last lesson of this track.
The model, stated plainly. Every table here assumes the same flat bet on every spin, exactly that many spins, and nobody stopping early. Real evenings do none of those things, so these are shares of runs of this model — not shares of people.
What is deliberately absent. There is no pace on this page: no spins a minute and no hours, so a run here is a number of spins and nothing else, and how long a run of that many spins takes at a real machine is left to the lessons that have a figure for it. There is no measure of how hard a run swings from spin to spin, and no figure for how often a machine pays beyond the one both machines share — how often a machine pays, and how big its prizes are, is the next lesson in this track. And there are two teaching machines rather than three, because two is how many shares a province has published in its own words for us to read.
Hosts. Leo and Maya are illustrated characters. Their backstories, a former dealer and a former floor supervisor, are written for the course: neither is a real person, and neither speaks for any casino. The rules and numbers on this page come from the sources it cites, not from their experience.
No promise. Nothing on this page says that one machine is a better choice than another, or that a longer run is, or that an evening at a casino is. In every table on this page the machine keeps a share of everything staked, on both machines and at every length of run.
What the house keeps is called
The pre-programmed amount that the house keeps is called the hold
OLG PlaySmart · Slots — odds · read
The minimum, and the bets it covers
The minimum theoretical payout percentage of a Game is eighty-five (85.000) percent.
Section 11.9 Game Payout
AGCO · Minimum Technical Standards for Gaming — 11. Game Behaviour · read
The minimum theoretical payout percentage of a Game must be met for every available Bet configuration.
Section 11.9 Game Payout
AGCO · Minimum Technical Standards for Gaming — 11. Game Behaviour · read
What a return-to-player figure is
Return to Player (RTP) is a term used to describe the percentage of winnings paid to players over a period of time. It is also a different way of stating the House Advantage.
Manitoba Liquor & Lotteries · Informed Gambling — House advantage · read
How the rate and the prize relate
All prizes are awarded randomly, whereas the chances to win are programmed according to the return-to-player (RTP) rate.
Loto-Québec · Wise Play — Your questions, our answers · read
The figure is a life cycle, not an evening
If a slot or VLT has a 92% payout over the lifetime of the machine, it doesn't mean that you will leave with 92% of the money you started with. This is the payout over the long run.
Manitoba Liquor & Lotteries · Informed Gambling — Slots and VLTs (brochure, February 2023) · read
But remember that outcomes are random and Return to Player is calculated over the whole life cycle of the game, not an individual player’s experience.
Manitoba Liquor & Lotteries · Informed Gambling — House advantage · read
When the payback percentage is 85%, this doesn’t mean that you can expect to win back $85 if you gamble $100 on that individual session.
OLG PlaySmart · Slots — odds · read
Look-alike machines
Two slot machines may look identical, yet may have different odds. So you can’t tell by the appearance of the machine.
OLG PlaySmart · Slots — odds · read
The minimum in Ontario
The minimum theoretical payout percentage of a Game is eighty-five (85.000) percent.
Section 11.9 Game Payout
AGCO · Minimum Technical Standards for Gaming — 11. Game Behaviour · read
The minimum theoretical payout percentage of a Game must be met for every available Bet configuration.
Section 11.9 Game Payout
AGCO · Minimum Technical Standards for Gaming — 11. Game Behaviour · read
The average in one province
The average return to player at B.C. casinos is 92 percent.
The average in another
the theoretical return to player for slot machines is 92% on average (although it can be higher in some cases), which means that about 8% of the total money wagered would go to the house
Loto-Québec · Wise Play — Understanding chance: Slot machines · read
A worked example, not a provincial figure
If a slot or VLT has a 92% payout over the lifetime of the machine, it doesn't mean that you will leave with 92% of the money you started with. This is the payout over the long run.
Manitoba Liquor & Lotteries · Informed Gambling — Slots and VLTs (brochure, February 2023) · read
But remember that outcomes are random and Return to Player is calculated over the whole life cycle of the game, not an individual player’s experience.
Manitoba Liquor & Lotteries · Informed Gambling — House advantage · read
What a room must make available
Patrons shall be provided with meaningful and accurate information to enable them to make informed choices.
Meaningful and accurate information on the odds of winning, payout odds or returns to patrons shall be clearly stated and made available to patrons.
Section 2.4
AGCO · Registrar’s Standards for Gaming — 2. Responsible Gaming · read
What the internet standard documents
Odds of winning for each prize available to players
The advantage of the operator in relation to each wager.
Section 4.05
AGCO · Registrar's Standards for Internet Gaming — Game Integrity · read
What reaches the player before a bet
contain comprehensive, accurate and understandable information on the odds of winning, payout odds, or returns to players
Section 4.06
AGCO · Registrar's Standards for Internet Gaming — Game Integrity · read
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