How Bookmakers Price Greyhound Markets

Behind the Odds: How the Market Gets Made

The odds you see on screen did not appear by accident. Behind every set of greyhound racing prices is a process — part science, part judgement, part reaction to money — that produces the market you bet into. Understanding that process does not give you a magic edge, but it does change how you interpret odds and helps you identify the moments when the market’s assessment diverges from reality.

Most punters treat odds as a given — a number to accept or reject. Experienced punters treat odds as an opinion expressed in numerical form. Every price on a greyhound represents the bookmaker’s assessment (adjusted for profit margin) of the probability that the dog will win. When you place a bet, you are not just predicting a result — you are disagreeing with that assessment, at least in part. The more you understand about how the assessment was formed, the better equipped you are to judge when it is wrong.

Tissue Prices and Initial Odds

The trader starts with a tissue — a rough probability assessment before the market opens. This is where greyhound prices begin their life, and it is more human and less algorithmic than many punters assume.

A tissue price (or tissue) is a bookmaker trader’s initial estimate of the fair odds for each runner in a race. It is called a tissue because it was traditionally written on tissue paper and passed to the board markers at the racecourse. In the digital age, the tissue is compiled in a spreadsheet, but the principle is unchanged: a skilled trader assesses the form, draw, running style, and grade of each dog in a six-runner race and assigns a probability to each one. Those probabilities are then converted to odds and adjusted upward to include the bookmaker’s margin.

The inputs to a tissue are the same factors that any punter would consider: recent form, times, grade, trap draw, running style, and trainer. The trader may also have access to trial times, insider intelligence on a dog’s condition, and historical data about how specific dogs perform at specific tracks. The quality of the tissue depends on the quality of the trader, and in greyhound racing — where markets are less scrutinised than in horse racing — the tissue can be significantly better or worse than the eventual Starting Price.

The tissue creates the initial market. When a bookmaker publishes early prices for an evening’s racing, those prices are based on the trader’s tissue adjusted for the desired margin. The initial prices are an invitation to bet, and the way punters respond to that invitation determines how the market evolves from opening to the off.

For the astute punter, the tissue stage is where the most significant pricing errors occur. The trader has limited time to assess each race — a typical evening card might feature twelve races, and the tissue for all twelve must be compiled within a few hours. Mistakes happen: a dog’s recent grade change is overlooked, a trap draw mismatch is under-weighted, or a trainer’s hot streak is not factored in. These early-market errors are the raw material of value betting, and they are available for a limited window before the market self-corrects through the weight of informed money.

The Overround: The Bookmaker’s Edge

A six-dog race priced to 115% means the bookmaker takes 15% before a dog even leaves the traps. That figure — the overround — is the structural advantage that bookmakers enjoy, and understanding it is essential to recognising what you are up against.

In a perfectly fair market, the implied probabilities of all six dogs would sum to exactly 100%. The prices would reflect each dog’s true chance of winning, and neither the bookmaker nor the punter would have a built-in advantage. In reality, the sum always exceeds 100% — typically between 112% and 125% for UK greyhound racing, depending on the bookmaker and the race. The excess above 100% is the overround, and it represents the bookmaker’s guaranteed margin before a single bet is settled.

The practical effect of the overround is that every individual price is slightly shorter than it would be in a fair market. If a dog’s true probability of winning is 25% (fair odds of 3/1), the bookmaker might price it at 5/2 (implied probability 28.6%). The difference — 3.6 percentage points — is the bookmaker’s share of the margin on that particular dog. Across all six dogs, these individual mark-ups compound into the total overround.

Overround varies between bookmakers and between races. Competitive markets — feature races with heavy betting turnover — tend to have lower overrounds because bookmakers sharpen their prices to attract money. Less competitive markets — midweek graded races at smaller tracks — tend to have higher overrounds because there is less pressure to be competitive. If you are choosing where to bet, comparing overrounds between bookmakers on the same race is a direct measure of who is offering better value. The bookmaker with the lower overround is returning more money to the market.

For punters, the overround means that simply picking winners at the strike rate implied by the odds is not enough to break even. You need to pick winners at a rate above what the odds imply, or consistently identify dogs whose true probability exceeds the implied probability embedded in the price. That is the mathematical definition of value, and it is the only sustainable path to long-term profitability in a market that is structurally tilted against you.

How and Why Prices Move

Money talks. When a 5/1 shot drifts to 8/1, the market is sending a message — and learning to read those messages can sharpen your betting significantly.

Prices move for two primary reasons: changes in information and changes in money. In practice, the two are often intertwined. Informed money — bets placed by punters who know something the market does not — causes prices to move because the bookmaker adjusts to manage their liability. Uninformed money — bets from casual punters who fancy a name or a trap number — also moves prices, but less reliably reflects the true probabilities.

Steaming is the term for a rapid shortening of a dog’s price, typically driven by heavy money from one or more significant sources. A dog that opens at 5/1 and is backed down to 3/1 within an hour has been steamed. The cause might be informed money from connections who know the dog is in exceptional form, or it might be a tipping service directing its subscribers to the selection. Either way, the price movement tells you that the market is reassessing the dog’s chances upward. Steamers do not always win, but they win at a higher rate than their opening price suggests — the market is correcting an initial underestimate.

Drifting is the opposite: a dog’s price lengthening from its opening mark. A drifter has attracted less money than the bookmaker expected, which can indicate a lack of confidence from informed punters, negative information circulating about the dog’s condition, or simply that the opening price was too short and the market is correcting. Drifters are not automatic lays, but persistent drifts — a price that has moved steadily outward from morning to afternoon — should prompt you to reconsider any positive assessment of the dog.

Late market movements in the final minutes before the off are the most informative. A dog that has been steady at 4/1 all afternoon and suddenly shortens to 3/1 in the last ten minutes has attracted significant last-minute money — often from sources close to the kennel or the track. These late moves are harder for the casual punter to react to (the bet needs to be placed quickly), but they are worth monitoring because they carry a high information density.

The practical application is to watch market movements as an additional data source, not as a substitute for form analysis. A dog you fancy that is also shortening in the market is a stronger proposition than one you fancy that is drifting. Price movement confirms or contradicts your own assessment, and using it as a final check before committing your stake can prevent you from backing dogs that the better-informed segments of the market have already discounted.

Understanding the Market Is Half the Battle

You are not just betting against other punters — you are betting against the bookmaker’s margin. That margin is built into every price, every market, every race. It does not sleep, it does not have bad days, and it does not forget to account for the overround. Your job as a punter is to find the races and the dogs where your analysis identifies a probability gap large enough to overcome that margin and produce a positive expected return.

Understanding how the market is made helps you do that job more effectively. When you know that tissues are compiled by humans under time pressure, you know that errors are inevitable — and that the first hour of a market’s life is when those errors are most likely to be present. When you understand the overround, you can calculate the true hurdle your selections need to clear. When you read price movements, you can triangulate your own form assessment against the market’s collective intelligence.

The bookmaker is not your enemy. The bookmaker is a business that sets prices designed to generate a profit margin. Your task is to find the prices where that margin has left room for a well-informed opinion to profit. It is a challenging task — the margin is real, the traders are competent, and the market corrects quickly. But it is not an impossible one, and the punters who understand the mechanics of price formation are the ones best placed to find the cracks.