Frequently Asked Questions
Plain-English answers to how HeatScore works — no betting jargon assumed.
What is a Heat Score?
A Heat Score is a 0–100 number that summarizes how much the betting market is heating up around one outcome — say, the Yankees to win tonight. It combines four signals: how far the line has moved since we started tracking the game (Steam), how fast it is moving right now (Velocity), whether any sportsbook is paying more than the rest of the market thinks the outcome is worth (Edge), and whether a book's own prices contradict each other (Gap). A high score means a lot is happening around that outcome. It does not mean the outcome is likely to win.
What does Steam mean?
Sportsbook odds can be translated into a percentage chance: decimal odds of 2.00 mean the market gives an outcome roughly a 50% chance. Steam measures how much that percentage has climbed since we first saw the game. If the Dodgers opened at 2.75 (about a 36% chance) and are now 2.20 (about 45%), that is roughly 9 points of steam — heavy, sustained money moving toward one side. A rise of 10 points or more earns full marks in the score.
What does Velocity mean?
Velocity is the same idea as Steam, but measured over just the last 30 minutes: how fast is the line moving right now? A line that creeps up 1 point over six hours is drifting; one that jumps 3 points in half an hour is reacting to something — an injury report, a lineup change, or a surge of sharp money. A move of 3 points in 30 minutes earns full marks.
What does Edge mean?
Edge compares one sportsbook's price to what all the books collectively think (their consensus fair probability, with each book's built-in fee removed). Suppose the consensus says a team has a 45% chance, but one book is still paying decimal odds of 2.50 — a price that implies only a 40% chance. Backing that price returns more than fair value: 0.45 × 2.50 = 1.125, a +12.5% edge. We require at least three tracked books quoting an outcome before computing an edge, so a single stale quote cannot fake one.
What does Gap mean?
Gap catches a single sportsbook disagreeing with itself. Some bets can be priced two different ways at the same book. In soccer, for example, a 'double chance' bet on 'Arsenal or Draw' should cost the same as Arsenal winning plus the draw, added together. If the book's own match-winner prices imply a 71% chance but its double-chance price implies 67%, that is a 4-point gap — one of those two prices has to be wrong. Gaps of 4 points or more earn full marks.
What does the ARB badge mean?
ARB is short for arbitrage. The badge appears when the best prices at different books disagree so much that backing every outcome of the game would cost less than 100% of the payout. Example: Lakers at 2.12 at one book (a 47.2% implied chance) and Celtics at 2.14 at another (46.7%) total only 93.9%. Books correct these windows within minutes. The badge is informational only and does not change the Heat Score.
What is de-vigging / fair probability?
Sportsbooks build a fee into their odds, known as the vig (or juice). Convert both sides of an evenly matched game priced at 1.91 into percentages and you get 52.4% + 52.4% = 104.8% — that extra 4.8% is the book's margin, which is why the numbers add up to more than 100%. De-vigging removes the fee by dividing each percentage by the total, restoring chances that sum to 100% (in this example, 50/50). Those de-vigged numbers are the 'fair probabilities' used everywhere on this site.
Why do some rows show 0.0pp steam?
Steam and Velocity compare current prices to our own earlier snapshots — we only trust history we collected ourselves. When a game first appears on the board there is nothing to compare against yet, so Steam starts at 0.0pp. As polls accumulate (every 30 minutes during event windows), the history fills in and Steam and Velocity start registering real movement.
Why are some rows blurred?
The Mispriced Board ranks outcomes by Edge and shows the top three for free. The rows below that are blurred until you subscribe with your email address. The free boards stay free because the full board is what supports the site.
How often does the board update?
An automated job polls the odds every 30 minutes during event windows — the hours when games are actually being bet. We deliberately stay inside a small daily request budget, so quiet hours are not polled. The footer of every page shows the time of the last update.
Which sportsbooks do you track, and why only regulated US books?
We track DraftKings, FanDuel, BetMGM, Caesars, BetRivers, ESPN BET, and Fanatics — all licensed and regulated in US states. Offshore books are excluded because their prices are often stale or impossible for US customers to actually bet, and a single junk quote would distort the consensus fair probability and manufacture edges that do not exist. Restricting to regulated books keeps every signal grounded in prices you can really get.
Is this betting advice?
No. HeatScore publishes signals, not predictions. A high Heat Score means the market is moving and prices disagree — it is not a forecast that an outcome will win, and it is not a recommendation to bet. Nothing on this site guarantees profit. If you choose to bet, never wager more than you can afford to lose. If you or someone you know has a gambling problem, call 1-800-GAMBLER.
How does the Live Calculator work?
It starts from two pre-match numbers. First, the favorite's moneyline becomes an implied percentage (a -188 line implies about 65%), and we strip roughly 6% of bookmaker fee to get a fair pre-match win chance. Second, the total-goals line is split between the two teams: the calculator searches a grid of Poisson scoring rates (the standard statistical model for goals) until it finds the split where the favorite's win probability matches that fair chance — giving each team an expected-goals rate. Live, those rates are scaled down by the time remaining, tilted by who is actually controlling play (possession and shot counts), and then adjusted for the event: a deserved goal counts more than a fluke, a red card multiplies the short-handed team's rate down and the other team's up, and a penalty is treated as a 78% chance of an instant goal. The result is a fresh win probability, fair odds, and an EV grade against the live price you type in. The event multipliers are heuristics, not gospel — treat it as decision support, never as betting advice.
How does premium work without an account?
Your email address is the membership. When you subscribe, payment runs through Stripe, and our systems sync the list of active subscribers from Stripe once a day. The daily optimized parlay then goes straight to your inbox — there is no password, no login, and no dashboard to check. Cancel anytime through Stripe and the emails stop after the next daily sync.
Where is my bet data stored?
Entirely in your own browser, using localStorage. Tracked bets and settled results never leave your device and are never sent to us — we could not read them if we wanted to. The flip side: clearing your browser data deletes them, and another device or browser starts empty. Use the Export button on the Portfolio page to download a JSON backup, and Import to restore it anywhere.
How does this site make money?
Two ways, both disclosed. First, some buttons link to sportsbooks through affiliate programs — if you sign up through one, we may earn a commission at no extra cost to you. Affiliate links never influence the boards: the scoring math runs the same whether or not a book pays us. Second, the email list that unlocks the full Mispriced Board helps sustain the site.