Patrick "Paddy" Kavanagh
Senior Betting Strategist & Advisor
After 15 years compiling odds for major Irish bookmakers, I'm sharing the insider perspective on how odds are set—and where punters can find genuine value.
For fifteen years, I sat on the other side of the counter. I compiled odds for several major Irish bookmakers, watched punters come and go, and learned exactly how the house maintains its edge. Now, I'm sharing that knowledge with you.
Most betting advice focuses on picking winners. But here's the secret that changed everything for me: picking winners isn't enough. To be profitable long-term, you need to find value—bets where the true probability of an outcome is higher than the odds suggest.
Let me pull back the curtain on how bookmakers actually work. It's more nuanced than most punters realise.
The Opening Line: For major events, odds compilers start with mathematical models. For a Premier League match, we'd feed in dozens of variables: recent form, head-to-head records, home/away performance, injuries, team news, even weather forecasts. The model produces probability estimates for each outcome.
The Overround: Here's the catch—the bookmaker doesn't offer fair odds based on true probabilities. They build in a margin, called the overround or "vig." If the true odds for an event sum to 100%, the bookmaker's odds might sum to 105%. That 5% is the house edge.
Market Pressure: Once odds go live, they're adjusted based on betting patterns. Heavy money on one outcome shortens those odds and lengthens others. This is where sharp bettors—professionals who consistently win—have significant influence.
Liability Management: Bookmakers don't just want to predict outcomes; they want balanced books. Sometimes odds are adjusted not because our view changed, but because we needed to attract or repel money on certain outcomes.
Understanding this distinction transformed my betting:
Primary Market Odds: The headline markets—match winner, first goalscorer, total goals. These are the most efficient markets. Bookmakers devote serious resources to getting these right, and they're heavily bet by professionals. Finding value here is possible but difficult.
Secondary Market Odds: Asian handicaps, exact scores, half-time/full-time. Less liquid, less scrutinised, more room for error. This is where I found most of my edge.
Novelty/Prop Odds: Player specials, exact corners, time of first goal. Often set by junior compilers with less expertise. The margins are usually higher, but so are the potential inefficiencies.
Value exists when the odds offered exceed the true probability of an outcome. Sounds simple, but how do you know the "true probability"?
Method 1: Build Your Own Model This is what professional bettors do. Gather data, identify predictive factors, weight them appropriately, and generate your own probability estimates. If your model says Manchester United have a 45% chance of winning but the bookmaker's odds imply only 40%, you've found value.
Method 2: Specialise Deeply You can't out-model the bookmakers across all sports. But you can know more than them about specific niches. Lower league football, non-marquee horse racing, niche sports—these are areas where your specialist knowledge can exceed the bookmaker's generalist view.
Method 3: Line Shopping Different bookmakers offer different odds on the same event. Consistently taking the best available price across multiple bookmakers can be the difference between winning and losing long-term. It's tedious but effective.
Method 4: Early Markets Odds are least accurate when they first open. If you have strong views before information is fully priced in, early betting can capture value that disappears as the market matures.
Let me walk you through a real example from my betting records (details slightly anonymised):
A Championship football match opened with the away team at 4.00 (implied probability: 25%). My analysis suggested: - Away team's underlying numbers better than results suggested - Key home defender injured (not yet widely reported) - Historical record at this ground favoured the away side - Motivation factor: away team needed points for playoffs
I estimated the true probability at around 32%. At 4.00 odds (25% implied), I had a value edge of 7 percentage points—significant enough to bet with confidence.
The away team won 2-1. But here's the important part: even if they'd lost, it would have been a correct betting decision. Value betting is about process, not outcomes. You judge decisions by logic, not results.
Confusing Value with Predictions: A 1.20 favourite can be poor value; a 5.00 outsider can be excellent value. The odds matter as much as the prediction.
Overconfidence in Your Edge: Unless you have proprietary information or significant analytical advantages, your "edge" might be smaller than you think—or nonexistent. Bet sizing should reflect uncertainty.
Ignoring the Overround: A bet that looks like value against fair odds might not be value against the actual odds after margin is applied. Always calculate what the odds imply.
Results-Oriented Thinking: One bet—or even one hundred bets—doesn't tell you if you're finding value. Variance dominates short-term results. Focus on making correct decisions; the results will follow eventually.
From my experience, here's where edges are most commonly found:
Early markets before information is priced in. If you know something relevant before the market does, you have an edge.
Inefficient leagues and competitions. The Bulgarian second division gets less attention than the Premier League. Less attention means more opportunity.
Secondary and tertiary markets. Total corners, specific goalscorer anytime, Asian handicaps—these markets often have softer odds.
In-play betting during key moments. Odds can overreact to events in live betting. A goal doesn't always shift the true probabilities as much as the market suggests.
Promotional and enhanced odds offers. When bookmakers offer enhanced odds for marketing purposes, they're literally giving away value. Take it.
Finding value is only half the battle. You also need: - Sufficient bankroll to withstand variance - Discipline to bet only when you identify value - Record-keeping to objectively assess your performance - Emotional control to avoid tilting after losses
Most people who think they've found value haven't. They've found opinions that feel confident. True value betting requires either exceptional specialisation, superior information, or quantitative models that outperform the market.
I don't say this to discourage you—I say it to calibrate expectations. Value betting is possible, but it's harder than most punters believe. The bookmakers are smart, well-funded, and have significant advantages. To beat them, you need to be smarter in your chosen niche.
After fifteen years on the bookmaker's side and ten years betting personally, here's what I know: value betting is real, edges exist, and skilled bettors can profit long-term. But it requires work, discipline, specialisation, and honesty about your actual capabilities.
If you're betting recreationally for entertainment, don't stress about value. Enjoy the experience and manage your bankroll sensibly.
If you're serious about profit, start treating betting like the analytical challenge it is. Build models, track results, learn from mistakes, and never stop questioning whether your edge is genuine.
The house doesn't always win. But it wins against those who don't understand how the game works.
Now you do.
Paddy
Senior Betting Strategist & Advisor
Veteran betting strategist with 25+ years of bookmaking and analysis experience.
View Profile
The biggest enemy in betting isn't the bookmaker—it's yourself. After decades watching punters self-destruct, I've identified the psychological traps that destroy bankrolls and how to avoid them.
After 25 years in the betting industry—15 as an odds compiler and 10 as an analyst—I've seen fortunes won and lost. The difference between survivors and casualties almost always comes down to one thing: bankroll management.