How to read Market Assessment
What four betting venues make of a match — and how to spot the one offering a price the others would not.
Version 1.5: changes and history
“What changed” compares observations for the selected market and source, with their actual times. “Price history” opens a graph and table for 24 hours or 7 days. The history uses bookmaker estimates after proportional margin removal and exchange bid/ask midpoints; these can differ from the normalized venue comparisons below. A changed bookmaker sample is labelled separately. Old data and missing history are shown explicitly. Collection and comparisons stop at kick-off.
Every match page on Real Sports Insider carries a section called Market Assessment. It shows what four different kinds of venue think the probability of each outcome is: the bookmakers' consensus, a betting exchange (Smarkets) and two prediction markets (Kalshi and Polymarket).
It is not a Real Sports Insider forecast. It is a reading of where money is actually sitting. And the useful part is not the average — it is the disagreement.
Read it in ten seconds
- The big percentage — the market's probability for that outcome, with the margin taken out.
- The small number beside it — the same probability written as decimal odds. That is a fair price, not an offer.
- Venue by venue — the same outcome as each venue prices it on its own.
- Best price — the longest price actually on offer right now, and how much money is available at it.
Taking the margin out
A bookmaker quoting 1.90 on both sides of a coin flip is not saying 52.6% and 52.6%. Those add up to 105.3%, and the extra 5.3% is the margin — the house's cut, baked into the price. Divide it out proportionally and you get the honest read: 50% and 50%.
Every percentage in this section has been through that step. It is the only reason a bookmaker line and an exchange can sit side by side at all: raw prices from two venues with different margins are not comparable numbers.
Why the venues disagree
A bookmaker sets a price and takes the other side of your bet. An exchange or a prediction market matches you against another person and charges a commission instead of building a margin into the price. That difference shows up in the numbers — sports contracts on Kalshi have been measured at well under 1% margin, against roughly 4–5% at a typical sportsbook.
Which gives you the rule the whole section rests on: treat the exchanges as the fair estimate, and the bookmakers as the offer you are testing against it.
Stripping the margin off a soft bookmaker gives you a tidied-up version of that bookmaker's opinion, not the truth. Stripping it off a market where thousands of people trade against each other gets you closer to a real probability. Average the two together and then hunt for value against a bookmaker, and you are partly comparing that bookmaker with itself.
Finding a price worth taking
Say the exchanges price a home win at 61%. As decimal odds that is 1 ÷ 0.61 = 1.64, and 1.64 is the fair price.
Now look at what you can actually bet. A bookmaker offering 1.75 is implying 1 ÷ 1.75 = 57.1%.
The market says 61%, the price says 57.1%, and the gap is 3.9 percentage points in your favour. Expected value per unit staked:
0.61 × 1.75 − 1 = +6.8%
That number is honest only if both inputs are. The probability has to come from the sharp side, and the odds have to be a price you can really get, after commission. Best price handles the second half for you: on an exchange it is the ask with that venue's commission already taken off, not the headline number on their screen.
So the job is not to find the team most likely to win. It is to find the case where the market's probability is higher than the probability implied by the odds in front of you.
The disagreement line
When the two camps are far enough apart, the card says so in plain words — for example: "The books rate this 2.3 pp higher than the exchanges — the bookmaker price is the short one."
Read the direction carefully, because it runs opposite to most people's instinct. If the exchanges rate an outcome higher than the books do, the books are the ones paying too much for it, and the long price is at the bookmaker. If the books rate it higher, their price is short and there is nothing there for you.
The line only appears when the gap clears two percentage points and there is enough money in the book for the gap to mean anything. Below that it is noise, and the card stays quiet rather than dressing noise up as a signal.
What the arrow measures
An arrow beside an outcome shows movement, but the two kinds of venue are measured differently — and the card spells out which is which under the source buttons. On an exchange the arrow compares observations; its tooltip states the actual interval. On the bookmaker line it covers the move since the line opened.
Movement at one venue alone is somebody's opinion. The same move appearing on the books and on two exchanges at once is the market changing its mind, and that deserves more of your attention.
Liquidity
This is the number that makes the others real. Money in the book is the money resting in unmatched orders right now — offers waiting for someone to take them, not volume already traded.
A generous price with nothing behind it is not a price. 1.82 with $35 available is worth less than 1.76 with $12,000 available: you cannot get a real bet down at the first one, and a deep book is a more trustworthy probability to begin with.
When a book is too thin for the split between outcomes to mean anything, the card hides the split and shows only the amounts. That is deliberate.
When to pass
- The venues disagree wildly with each other — nobody has a firm read, including you.
- The book is thin, or the size at the best price is tiny.
- The price has already moved past fair while you were reading.
- The move shows at one venue only.
- The edge is half a point or a point — that is inside the error of the estimate.
No edge, no bet. On most matches on most days there is nothing here, and finding that out in ten seconds is a large part of what this section is for.
What this section is not
It is not a prediction from us and it does not tell you who will win. Every percentage is the market's opinion, and markets are wrong regularly.
One number keeps its margin on purpose: Best price is a real offer, not an estimate. Everything else has been de-margined.
Collection stops at kick-off. If a match has started, you are looking at the last pre-match reading, and the card labels it as such.
Seeing it on a match
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