The Live Overlays board is one of the least obvious things on this site, so here is the whole idea in plain English, with the arithmetic shown. If you have never bet a horse before, start at the top: the second section explains why a good price matters more than a good pick, and that idea is the reason this board exists. If you just want to know what the columns mean, jump to Reading the board.
The one idea: odds are prices, and sometimes the price is wrong
In horse racing the odds are not set by a bookmaker. They are set by the crowd. Every dollar bet on a horse goes into a shared pool (the tote), and a horse's odds are simply how much of the pool is not on that horse. If lots of people back a horse its odds get shorter; if nobody does, its odds drift longer. The odds are a price, and the crowd sets it.
That price is a prediction. Odds of 3-1 mean the crowd is treating the horse as roughly a one-in-four chance. And like any crowd prediction, it is usually about right and occasionally quite wrong.
An overlay is a horse whose price is longer than it should be: the crowd is offering you 9-2 on a horse we think is a 5-2 chance. An underlay is the opposite, a horse being bet down to a price shorter than it deserves. The Live Overlays board does one job: it watches the live prices during the racing day and lists the horses the crowd is, in our model's opinion, under-rating.
Why an overlay is the thing we are looking for: value
Here is the part that surprises most newcomers: picking winners is not how you make money at the races. Getting a good price is. You can pick a lot of winners and still lose, and you can pick fewer winners and come out ahead. The difference is entirely in the price you were paid, and the word for a price that is better than the horse deserves is value. An overlay is value, made visible.
Two bettors, one season, both betting $2 a race on 100 races:
| Bettor A: backs the favourite every race | Bettor B: backs overlays | |
|---|---|---|
| Horses picked | Favourites at 2-1 | Horses at 6-1 that are really one-in-five chances |
| Winners out of 100 | 33 (a very good strike rate) | 20 (a modest one) |
| Money bet | $200 | $200 |
| Money back | 33 × $6 = $198 | 20 × $14 = $280 |
| Result | −$2, a loss, with 33 winners | +$80, a 40% profit, with 20 winners |
Bettor A was right far more often and still lost. Bettor B was wrong four times out of five and made money. That is not a trick of the example; it is the whole game. A 2-1 favourite that wins a third of the time is priced exactly right, so there is nothing in it for you, and after the track's cut (the takeout, roughly 15 to 20 cents of every dollar bet on most tracks) there is slightly less than nothing. A 6-1 horse that wins one race in five is priced wrong, in your favour, and that mispricing is where every dollar of long-run profit comes from.
This is why the board does not ask “who wins?” It asks “where is the crowd's price too generous?” The crowd is good at this, which is why real overlays are scarce and why most of the rows you will see are horses the crowd is actively abandoning (the ⚠️ badge, explained below). But the crowd is not perfect, and when its price on a horse is longer than that horse's true chance deserves, taking that price is the only bet in racing with the maths on your side. Everything else on this page, the Win%, the fair odds, the Edge/$1 column, exists to measure one thing: how far the price is from where it should be.
One honest caveat before the arithmetic: “true chance” is something nobody knows for certain. Our model estimates it, and the board's overlays are only as real as that estimate. That is why the record is graded every week and published further down this page.
The two numbers that matter
1. Win% — our estimate. Our AI Win Probability model (Algo 3 on the AI Picks post) gives every horse in the race a chance of winning, and those chances add up to 100% across the field. A 25% horse is one we expect to win one race in four.
2. Fair odds — that estimate turned into a price. If a horse wins one race in four, the break-even price is 3-1: you lose $1 three times and win $3 once. In general, fair odds = (1 ÷ Win%) − 1. A few worked examples:
| Win% | The maths | Fair odds | In words |
|---|---|---|---|
| 50% | (1 ÷ 0.50) − 1 = 1 | 1-1 (even money) | wins every other race |
| 33% | (1 ÷ 0.33) − 1 = 2 | 2-1 | wins one in three |
| 25% | (1 ÷ 0.25) − 1 = 3 | 3-1 | wins one in four |
| 20% | (1 ÷ 0.20) − 1 = 4 | 4-1 | wins one in five |
| 10% | (1 ÷ 0.10) − 1 = 9 | 9-1 | wins one in ten |
Fair odds are the price at which, if our estimate is right, you would break even over the long run. Anything longer than fair is a price in your favour. Anything shorter is a price against you.
A worked example
Take a horse we will call Example Runner, running in race 5 at Saratoga.
- Win%: 28%. Our model thinks she wins a little better than one race in four.
- Fair odds: 5-2. (1 ÷ 0.28) − 1 = 2.57, which the board rounds to 5-2. That is her break-even price.
- ML: 3-1. The morning line, the track handicapper's guess at the odds, printed the night before. It is a forecast, not a real price.
- Live: 9-2. What the tote is actually paying right now, captured a few minutes ago.
The crowd is offering 9-2 on a horse we make a 5-2 chance. That is an overlay. The board expresses it two ways:
- Overlay: +80%. The live price (4.5) is 80% longer than the fair price (2.5). Bigger is better, up to a point (see the badges below).
- Edge/$1: +$0.54. This is the expected profit on a $1 win bet if our Win% is right. The maths: 0.28 × (4.5 + 1) − 1 = 0.54. In words: 28% of the time you collect $5.50 (your dollar back plus $4.50 in winnings), 72% of the time you lose the dollar, and on average that works out to 54 cents of profit per dollar bet. A positive edge means the price is in your favour; a negative edge means it is not.
Now the opposite case. Suppose the crowd loves Example Runner and bets her down to 2-1. Her fair odds are still 5-2, so 2-1 is shorter than fair: the crowd is paying less than we think she is worth. The edge is 0.28 × (2 + 1) − 1 = −$0.16, a loss of 16 cents per dollar over time. She is an underlay, and she does not appear on the board at all. The board only shows horses whose live price is at least 25% above fair.
Reading the board, column by column
| Column | What it is |
|---|---|
| Horse (#post) | The horse and its post position (the number on the saddle cloth). Click the name for its Smart Stats card. Underneath: the track, race number, minutes to post, and how old the captured price is. |
| Win% | Our AI Win Probability model's chance that this horse wins. The whole field adds up to 100%. |
| Fair | The break-even price for that Win%: (1 ÷ Win%) − 1. |
| Live | The tote price at the last capture. Prices are captured every ten minutes during racing hours, so this is a snapshot, not the price you will get at the window. |
| ML | The morning line: the track's overnight forecast of the odds. Useful only as a reference point for the badges. |
| Overlay | How much longer the live price is than the fair price, as a percentage. The board lists horses at +25% or more. |
| Edge/$1 | Expected profit per $1 win bet at the live price, if our Win% is right: Win% × (Live + 1) − 1. An estimate, never a promise. |
The two badges
An overlay can exist for two very different reasons, and the badge tells you which.
🔥 Money coming in. The live price is shorter than the morning line: people are betting this horse, and it is still an overlay. Somebody with an opinion agrees with our model. In our live-odds data, horses being bet down win far more often than horses drifting out, so an overlay that also carries the 🔥 badge is the strongest situation this board shows. It is also rare.
⚠️ Drifting. The live price is at least 25% longer than the morning line: the money is going elsewhere. The overlay exists because the crowd is walking away from this horse, and the crowd is often right to. Treat a drifter as thin-pool noise until its price holds within about twenty minutes of post, and pass if the drift keeps widening. Most rows on the board carry this badge, which is worth knowing before you get excited about a big overlay number.
What the board is not
- It is not a list of picks. The AI Picks post says who we think wins. This board says where the price looks wrong. A horse can be a big overlay and still be the fourth-most-likely winner in the race.
- The edge is only as good as the Win%. If the model over-rates a horse, the “overlay” is an illusion. Every number here rests on that one estimate.
- The live price is not your price. Prices move right up to post time, and they move most on the horses on this board: an overlay is by definition a horse the crowd is not backing, and when late money arrives the overlay shrinks. Early in the day the pools are tiny and the prices are almost meaningless.
- Scratched horses are removed as soon as the scratch is official.
How to use it well
- Look late, not early. Check the board within about twenty minutes of post time, when the pools have real money in them. A row that says “price 40 min old” is history.
- Read the badge before the overlay number. A modest overlay with 🔥 beats a huge overlay with ⚠️.
- Be wary above 10-1. The long-priced rows have been the weakest part of the board by a wide margin.
- Cross-check with the AI Picks post. If the overlay horse is also one of the model's top two choices in the race, the two signals agree. If it is the sixth choice, the price is the only thing in its favour.
- Bet small and bet the same amount each time. Edge/$1 is an estimate with a lot of noise in it. The Kelly Edge Plays table (Handicapper tier) turns these edges into suggested stake sizes; a quarter of what the maths suggests is a sensible starting point.
Glossary
- Tote — the shared pool of all bets on a race. The odds come from how the pool is split.
- Morning line (ML) — the track handicapper's forecast of the odds, printed the night before. A guess, not a price.
- Live odds — the actual tote price at a moment in time.
- Fair odds — the break-even price implied by a win probability: (1 ÷ Win%) − 1.
- Overlay — a horse whose price is longer than fair. Underlay — shorter than fair.
- Edge — expected profit per dollar bet at a given price, if the probability is right.
- MTP — minutes to post, i.e. minutes until the race starts.
- Post position — the horse's starting-gate number, which is also the number on its saddle cloth.
The Live Overlays board is part of the Handicapper plan and above; everyone can see a sample of how it looks. If a column or a number on it is still unclear after reading this, tell us and we will improve the explanation.
