The mathematics of gambling extends far beyond a single house-edge percentage. Probability, expected value, variance, volatility, game design, and behavioral mechanics all influence how gambling products work and how players experience them.
For Matthew Foster, Co-Founder and Editorial Director of WinnerGambling.com, that interest began during university with blackjack strategy and probability and eventually developed into a broader focus on explaining gambling mathematics through digital publishing.
Founded in 2008, WinnerGambling has evolved from a group of gamblers, poker players, casino regulars, and people interested in gambling mathematics into an independent information resource covering casino games, online casinos, poker, sports betting, bingo, and gambling mathematics.
In this interview, Foster discusses the mathematics behind modern gambling, the limitations of commonly cited figures such as RTP and house edge, the behavioral mechanics used in contemporary games, the challenge of gambling misinformation, and the growing role of AI in gambling publishing.
Interview with Matthew Foster
Your interest in gambling mathematics began during university, particularly through blackjack strategy and probability. What was it about blackjack that first made you interested in treating gambling as a mathematical subject rather than simply a form of entertainment?
Blackjack makes the relationship between decisions and probability unusually visible. You can look at a particular hand, identify the available choices, and examine how each decision changes the expected outcome. What interested me was that the game wasn’t simply about whether you won or lost a particular hand. There was a larger mathematical framework underneath those individual results. Strategy, probability, expected value, and variance all interact. That was the point where gambling became more interesting to me as a subject of analysis. Once you start looking at the mathematics, you realize that many gambling outcomes that feel surprising over a short period are entirely consistent with probability.
Probability theory can look remarkably clean on paper. What did you discover when you began comparing those theoretical models with the realities of casino environments?
The biggest difference is that mathematical models describe distributions of outcomes, while people experience individual outcomes. A theoretical expectation might make sense over a sufficiently large number of trials, but a player doesn’t experience the long run as a single smooth curve. They experience individual wins, losses, and unusually long sequences. There are also practical considerations that don’t necessarily appear in a basic probability equation. Game rules, variations in RTP, volatility, payment conditions, and the way information is presented can all affect how someone understands a product. That distinction between the mathematical model and the real-world experience is important when producing gambling content.
The house edge is one of the most frequently cited figures in gambling. What does it actually tell a player, and what can be missed when that number is considered in isolation?
The house edge is useful because it describes the mathematical advantage built into a game over the long run under specified conditions. But it doesn’t tell you exactly what will happen during a particular session. It also doesn’t fully describe the distribution of outcomes. Two games can have similar long-term theoretical returns while producing very different short-term experiences because of differences in variance or volatility. That’s why I think readers should treat the house edge as one part of the mathematical picture rather than the entire picture.
Players often focus heavily on RTP when comparing slots and other casino games. How should RTP be considered alongside volatility and hit frequency?
RTP is a long-term theoretical measure, not a prediction of what an individual player will receive back. Volatility adds another layer because it helps describe how outcomes can be distributed. A game can have a particular RTP but produce relatively frequent smaller wins, while another game with a similar theoretical return can have much more uneven outcomes. Hit frequency is another useful piece of information, although it shouldn’t be interpreted as a guarantee that a player will experience a particular number of wins. The key is context. A single percentage doesn’t tell the entire story.
Modern slots increasingly combine large potential multipliers with less frequent significant wins. From a mathematical perspective, what does greater volatility mean for bankroll longevity?
Higher volatility generally means a wider distribution of outcomes. That can mean larger positive or negative swings over a relatively small number of plays. For a fixed bankroll, larger swings can naturally mean a greater possibility of experiencing substantial losses before the long-term mathematical expectation has much opportunity to become visible. That doesn’t mean volatility changes the underlying RTP. It changes the way outcomes are distributed around that expectation. That’s an important distinction.
Some games are available at multiple RTP configurations. What challenges does this create for gambling publishers?
It creates a verification problem. If the same game exists at different RTP settings, simply quoting a figure from a general game database may not accurately describe the version available through a particular operator. That is why current operator information, published game details, and other appropriate sources need to be checked. When something cannot be confirmed, it is better to acknowledge the uncertainty than to present a potentially incorrect figure as fact.
Losses Disguised as Wins can use celebratory sounds and visual effects even when the returned amount is below the original wager. How important is it for gambling information platforms to explain these mechanics?
It’s important because the mathematical result and the way that result is presented are two different things. If someone wagers a certain amount and receives less back, the mathematical outcome is still a loss even if the interface presents it with celebratory sounds or animations. Readers don’t necessarily need a technical psychology lecture every time they encounter a game mechanic, but they should understand what the numbers actually mean. Good gambling information should help separate the presentation of an outcome from the underlying financial result.
Online gambling interfaces can incorporate default bet amounts, rapid deposits and timed prompts. Where do you draw the line between useful UX design and problematic digital nudging?
Context matters. Good UX should make a product easier to understand and use. The concern arises when a design deliberately makes a financially consequential action easier to take without giving the user enough opportunity to understand that action. For publishers, the important role is not necessarily to label every design decision as good or bad. It’s to explain relevant mechanics clearly and give readers enough information to make their own judgments.
Loot boxes, skin gambling, and crash-style games have blurred some traditional boundaries between gaming and gambling. What should readers understand about these newer formats?
They should start by asking what the underlying mechanism actually is. What determines the outcome? What is the probability distribution? Is there a financial cost? Can something of value be won or lost? Is the outcome determined by skill, chance or a combination? Those questions are often more useful than relying on the label attached to the product.
Martingale systems, betting patterns and claims about predicting supposedly random outcomes remain widespread. Why do these misconceptions persist?
One reason is that people naturally look for patterns in random sequences. Another is that short-term results can appear to confirm a strategy even when there isn’t a mathematical basis for expecting it to work over time. A betting system can change the sequence of wagers without changing the underlying house edge of the game. Increasing the size of a bet after a loss, for example, doesn’t make the previous loss disappear or change the probability of the next outcome. That’s why gambling mathematics is valuable. It gives readers a framework for separating an interesting pattern from a statistically meaningful one.
Winner Gambling’s process includes research, source evaluation, fact-checking and specialist review. What has to happen before a mathematical claim is considered reliable enough to publish?
It depends on the claim. A mathematical explanation needs to be consistent with the underlying calculation or established mathematical principle. A claim about an operator may require current operator information and terms. A regulatory statement requires an appropriate regulatory or government source. We don’t have one universal evidence threshold because different claims require different forms of verification. The important principle is that the source should actually support the specific claim being made.
Your editorial policy says Winner Gambling would rather flag uncertainty than fill an information gap with a guess. Why is that particularly important in gambling publishing?
Because an incorrect piece of information can affect a real financial decision. An incorrect bonus condition, game rule, payment detail, or mathematical explanation isn’t simply a cosmetic editorial error. Someone may rely on it when deciding whether to use a product. There is nothing wrong with saying that something couldn’t be independently verified. In many cases, that’s more useful and more honest than manufacturing certainty.
Winner Gambling maintains advertising and affiliate relationships while separating those relationships from editorial judgment. How do you maintain that distinction?
The distinction starts with recognizing that commercial relationships and editorial conclusions are different things. Affiliate compensation doesn’t change a mathematical calculation. An advertiser shouldn’t determine whether a factual statement is included. If information is unfavorable to a commercial partner but relevant and verifiable, it still needs to be represented accurately. We don’t claim that commercial relationships don’t exist. We make the relationship clear while maintaining that it shouldn’t determine the underlying editorial conclusion.
Winner Gambling began partly because the founders felt there was too much gambling content and not enough useful information. Has that problem changed?
The volume has certainly increased, but volume and quality have never been the same thing. One of the problems we noticed early was that an unsupported claim could become difficult to distinguish from established information simply because it appeared repeatedly across different websites. The challenge today is more complicated because there is even more content being produced. That makes source evaluation, verification, and clear explanation increasingly important.
Generative AI can produce convincing explanations while getting probability, RTP or game rules wrong. What safeguards do gambling publishers need?
The most important safeguard is remembering that AI output isn’t automatically evidence. AI can be useful for organizing information, assisting with drafting or helping editors work through large amounts of material. But important factual and mathematical claims still need human review. We also have to be particularly careful about fabricated sources, statistics, quotes or first-hand experiences. A system producing fluent text doesn’t mean the underlying information is correct.
Could AI also improve gambling research?
Potentially, yes. AI could help identify inconsistencies, organize large datasets, compare information or make complicated concepts easier to explain. Those are useful applications. But there is a difference between using AI as an analytical or editorial tool and treating its output as an authoritative source. The latter creates obvious risks, particularly in a field where mathematical accuracy matters.
If you could correct one persistent misunderstanding about gambling mathematics among players today, what would it be?
Probably the idea that understanding the mathematics allows you to predict individual outcomes. Mathematics can tell you about probabilities, expected values, and distributions. It doesn’t tell you what the next spin, hand, or bet will produce. Understanding the mathematics is valuable precisely because it helps you understand uncertainty rather than eliminate it.
Finally, if you could make every new player understand one mathematical concept before placing their first bet, what would it be?
I’d choose expected value because it provides a useful foundation for understanding the difference between an individual outcome and a long-term mathematical expectation. A player can win a game with a house edge, just as they can lose a game where they made a mathematically sound decision. A single result doesn’t invalidate the underlying probability. Once you understand that distinction, concepts such as house edge, RTP, variance, and volatility become much easier to put into perspective. The goal isn’t to make gambling predictable. It’s to make the numbers understandable enough that people know what those numbers can and cannot tell them.
This content is provided for informational purposes only and is not a substitute for professional advice. AFP editorial staff were not involved in the creation of this content.
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