Glossary

Racing & betting terms, defined

The vocabulary of racing and betting, in plain English. Bookmark it.

SP (Starting Price): The official price of a horse at the moment the race starts, set from the on-course market. Used to settle bets and as the benchmark for closing-line value.
BSP (Betfair Starting Price): The starting price calculated by the Betfair exchange by matching all SP bets at the off. Often differs from the official SP and is widely used to measure value.
CLV (Closing Line Value): Whether the price you took beat the market's final (closing) price. The single hardest metric to fake and the best long-run signal that a process has an edge.
Each-way: Two bets in one: half your stake on the win, half on the horse finishing in the places. Place terms (number of places and the odds fraction) depend on the race.
Place terms: How an each-way place pays — a fraction of the odds (e.g. 1/4 or 1/5) across a set number of places that scales with field size and race type.
NAP: A tipster's single most confident selection of the day. 'Next Best' is the second tier; Algohorse also publishes Speculative selections.
Favourite–longshot bias: The persistent market pattern where longshots are overbet and favourites underbet relative to their true chances.
Steamer: A horse whose price is shortening (being backed in) in the market before the off — the opposite of a drifter.
Drifter: A horse whose price is lengthening (drifting out) in the market before the off, suggesting weakening support.
Handicap: A race in which horses carry different weights based on official ratings, intended to give every runner a theoretically equal chance.
Going: The condition of the racing surface, from firm to heavy, which materially affects which horses are suited.
Draw bias: An advantage or disadvantage conferred by a horse's stall position, depending on course, distance and conditions.
ROI (Return on Investment): Profit or loss as a percentage of total stakes. Reported by Algohorse with confidence intervals once the sample is meaningful.
Edge: A genuine, repeatable advantage over the market — evidenced over time by positive closing-line value, not by a run of winners.
Calibration: Whether stated probabilities match reality: if a model says 70%, do those selections place 70% of the time? Good calibration means honest confidence.
Accumulator: A single bet combining several selections, where each winner's returns are staked on the next. Big potential returns, but every leg must win.
Double: An accumulator of two selections; both must win for the bet to pay out.
Treble: An accumulator of three selections; all three must win.
Lucky 15: A bet of 15 bets across 4 selections — four singles, six doubles, four trebles and a fourfold — so it can return even if only one wins.
Yankee: An 11-bet multiple across 4 selections (six doubles, four trebles, one fourfold), needing at least two winners to return.
Rule 4: A deduction from winnings when a horse is withdrawn before the off, reflecting that the remaining runners' chances improved. The bigger the withdrawn horse's price, the smaller the deduction.
Dead heat: When two or more horses can't be separated at the line. Stakes are split proportionally — you win the bet but at a reduced return.
Non-runner: A horse declared but withdrawn before the race. Win bets are refunded; in multiples the leg is usually void and the rest stands.
Ante-post: Betting well in advance of a race, often at bigger prices — but usually with no refund if your selection doesn't run.
Tote: Pool (pari-mutuel) betting: all stakes go into a pool and the dividend depends on how much is bet on the winner, not a fixed price.
Odds-on: A price shorter than even money (decimal under 2.0), where you stake more than you stand to win — the market's strong favourite.
Evens: Even money, 1/1 or 2.0 decimal — you win the same as you stake. Implied probability of 50%.
Overround: The sum of a market's implied probabilities above 100%. The excess is the bookmaker's built-in margin — the reason the average punter loses over time.
Value: A bet where the true chance of winning is greater than the price implies. Backing value consistently — not backing winners — is what makes betting pay.
Kelly criterion: A staking formula that sizes bets by your estimated edge and the odds, maximising long-run bankroll growth. Most bettors use a fraction of full Kelly to reduce variance.
Bankroll: The money you set aside for betting. Sound staking sizes each bet relative to the bankroll so a losing run can't wipe you out.
Level stakes: Staking the same amount on every bet — the fairest way to measure a tipping record, since returns don't depend on a staking plan.
Maiden: A horse (or race for horses) that has never won. Maiden races are often where unexposed, improving types are found.
Novice: In jumps racing, a horse in its first season over hurdles or fences. Novice form can be hard to weigh as horses learn the job.
Group race: The top tier of Flat racing — Group 1, 2 and 3 — the championship level. 'Graded' is the jumps equivalent.
Listed race: A class of Flat race just below Group level — black-type, but a step below the Group races.
Flat racing: Racing on the level with no obstacles, run on turf or all-weather. The Flat season peaks in summer.
National Hunt: Jump racing — over hurdles and fences — with its winter-centred season and the Cheltenham Festival as its pinnacle.
Hurdle: A jumps race over smaller, flexible obstacles — typically a horse's introduction to jumping before chasing.
Chase: A jumps race over larger, fixed fences — a sterner test of jumping and stamina than hurdling.
Bumper: A National Hunt flat race for future jumpers with no obstacles — a gentle introduction to racing.
Weight-for-age: A scale that gives younger horses a weight allowance against older rivals to reflect their immaturity.
Official rating: A handicapper's mark of a horse's ability, used to set the weights in handicaps. It rises and falls with performance.
Betting exchange: A marketplace where punters bet against each other rather than a bookmaker, and can both back and lay. Prices are keener and you can trade positions.
Lay: Betting that something won't happen — acting as the bookmaker on an exchange by accepting someone else's back bet.
Best odds guaranteed: A bookmaker concession: if your horse's SP is bigger than the price you took, you're paid at the bigger price. A real, free edge — always worth taking.
Extra place: A promotion paying more each-way places than standard terms. In big fields it can turn a losing each-way bet into a profitable one.
Furlong: An eighth of a mile (220 yards), the standard unit of racing distance. A five-furlong sprint is the minimum trip.
Headgear: Equipment like blinkers, cheekpieces, a hood or a visor fitted to help a horse concentrate. First-time headgear is a noted angle.
Gelding: A castrated male horse. Gelding often improves temperament and focus, and a recent gelding operation can spark improvement.
Photo finish: When the judge uses the finish-line camera to separate horses too close to call by eye.
Stewards' enquiry: An official review of a race — for interference or riding — that can change the result by disqualifying or demoting a horse.