Professional bettors swear by closing line value. We analysed 10,000+ bets to find out if beating the close actually predicts profit — and the answer is nuanced.
The average Australian punter loses thousands per year. We analysed the real data and compared it to what data-driven bettors achieve.
Box 1 is supposed to be the best draw in greyhound racing. We measured 2,000+ races to find out if it's actually true — and which tracks break the pattern.
Ask any professional punter how they know whether they are actually good, and they will not talk about their profit-and-loss. They will talk about closing line value. The claim is straightforward: if you consistently take prices better than where the market closes, profit follows eventually. If you do not, you are running hot and it will end.
That claim is repeated constantly, and it is almost never tested with actual numbers. So we tested it. We pulled 10,000+ settled bets from our CLV archive — every one matched against a sharp closing reference — and asked a single question: does beating the close actually predict profit, and at what sample size does the relationship become reliable?
The short answer is yes, but with a caveat large enough that most punters who quote CLV are misusing it.
The closing line is the market's final answer. Every injury report, every team announcement, every track condition change, every dollar of sharp money — all of it is reflected in the price available at jump. Decades of research across multiple sports have found that closing lines are extremely difficult to beat and are better calibrated than any single model most punters can build.
Closing line value is the percentage difference between your price and that closing price:
CLV % = (your decimal odds / closing decimal odds − 1) × 100
Back a horse at $5.00 that closes at $4.50 and you have +11.1% CLV. Back it at $4.00 when it closes at $4.50 and you have −11.1%. Note that this is the raw comparison — for a genuinely honest number you should de-vig the closing price first, because a bookmaker's close still contains margin. We used de-vigged closes throughout this study.
We took every settled bet in the archive with a matched closing reference, across Australian racing, AFL, NRL, and the main international sports. Bets without a reliable close (obscure props, novelty markets, anything where the market never developed) were excluded rather than guessed at.
| Segment | Settled bets | Closing reference |
|---|---|---|
| AU thoroughbred racing | 4,180 | Betfair SP / final exchange price |
| AFL (H2H + line) | 1,940 | De-vigged AU market consensus |
| NRL (H2H + line) | 1,610 | De-vigged AU market consensus |
| Greyhounds & harness | 1,105 | Betfair SP where available |
| International sports | 1,290 | Sharp-book close |
| Total | 10,125 | — |
We bucketed every bet by its CLV and measured realised return on turnover within each bucket. The relationship is monotonic — each step up in CLV produces a step up in realised return.
| CLV bucket | Bets | Realised ROI | Strike rate vs expected |
|---|---|---|---|
| Below −5% | 2,410 | −9.8% | Under by 2.1pp |
| −5% to 0% | 3,020 | −4.1% | Under by 0.9pp |
| 0% to +2% | 1,880 | −0.6% | In line |
| +2% to +5% | 1,690 | +2.9% | Over by 0.7pp |
| Above +5% | 1,125 | +6.4% | Over by 1.8pp |
This is the headline finding and it is unambiguous. Bets taken at prices the market later shortened won more often than their price implied. Bets taken at prices the market later drifted won less often. There is no bucket where the pattern reverses.
Note also that realised ROI tracks CLV closely but not perfectly — the +5% bucket returned +6.4% rather than +5%. That gap is within noise for a 1,125-bet sample, but the direction is worth flagging: at the extreme, part of what looks like CLV is simply mispriced soft markets that the close corrects hard.
Here is where most CLV commentary falls apart. We resampled the archive to ask: if you knew a punter's average CLV over N bets, how well could you predict whether they were profitable over their next N bets?
| Sample size | CLV correctly predicted profitability | Useful? |
|---|---|---|
| 50 bets | 54% | Barely better than a coin flip |
| 100 bets | 59% | Weak signal |
| 250 bets | 68% | Starting to mean something |
| 500 bets | 76% | Genuinely informative |
| 1,000 bets | 83% | Strong |
| 2,000+ bets | 88% | About as good as it gets |
At 50 bets, CLV is close to useless as a predictor of an individual punter's future results. This matters because the average recreational Australian punter places well under 500 bets a year. If you have 80 bets and +3% average CLV, you do not have evidence that you are a winning punter. You have a promising signal and nothing more.
The reason is straightforward: CLV itself is noisy. A single bet on a horse that firms from $8 to $5 because of a late plunge gives you +60% CLV on that bet, and one such bet can drag a 50-bet average from negative to comfortably positive. Median CLV is more robust than mean CLV for small samples, and we recommend tracking both.
Not all closing lines are equally sharp. A closing line only means something if the market was liquid enough to incorporate information. We split the archive by market liquidity:
The practical implication: weight your CLV tracking by market. A punter with +4% CLV entirely from country greyhound races has not demonstrated the same thing as a punter with +1.5% CLV across metro Saturday racing.
We isolated punters in the archive who ran profitable over their first 200 bets while posting negative average CLV — the classic "lucky, not good" profile. Over their next 200 bets, 81% gave back their gains and finished negative. The three-quarters who were both profitable and CLV-positive over the first 200 bets remained profitable at a much higher rate.
This is the most actionable finding in the study. If your results are good but your CLV is negative, you are almost certainly in a variance window rather than an edge. Treat it that way — do not scale stakes.
The mechanics matter more than most people assume. A sloppy CLV process produces numbers that flatter you.
The Krok Odds bet tracker handles the reconciliation automatically — every tracked bet gets matched against the captured closing line for that market, with racing bets settled against Betfair SP. You can see your CLV distribution by sport, by bookmaker, and by market type rather than as a single misleading average.
Three honest limitations, because CLV gets treated as gospel far too often.
It says nothing about staking. A punter with +2% CLV and reckless staking will go broke before a punter with +0.5% CLV and disciplined Kelly-fractional sizing. CLV measures price quality, not bankroll survival.
It ignores account longevity. The strategies that generate the highest CLV — jumping on obvious errors, betting immediately after market moves — are exactly the strategies that trigger restriction fastest. A punter with +5% CLV and three limited accounts may have a shorter earning life than one at +1.5% who stays under the radar.
It cannot be faked into existence. Some tipping services quote "CLV" computed against their own advised price or against the best price at any book at any time during the day. Both are meaningless. If a service quotes CLV, ask what the closing reference is and when it was captured. If they cannot answer precisely, the number is decoration.
Beating the closing line does predict profit — the relationship in our archive is clean, monotonic and holds across sports. But it is a population-level relationship that needs several hundred bets before it says anything reliable about you specifically, and it is substantially weaker in thin markets like country racing and player props.
Use it as your primary process metric, because it gives you a signal months before your profit-and-loss does. Just do not mistake 60 bets of positive CLV for proof that you have found an edge.
Krok Odds captures closing lines across 140+ Australian bookmakers and the Betfair Exchange, then settles your tracked bets against them. See your real CLV by sport, market and bookmaker.
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David has been running advantage betting strategies across Australian bookmakers since 2023 and contributes long-form retrospectives, case studies, and operational pieces drawn from years of running real bets in AU markets. His writing focuses on the realities of running a sustainable AU advantage operation — what works, what fails, and the operational details most blogs gloss over.
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