A plain English explanation of what the number means, where it comes from, and why you can trust it.
Want the full technical detail? It's in collapsible sections marked ⚙️ — open them if you're curious, skip them if you're not.
Every horse in every race gets a number from 0 to 100. That number is our best estimate of the horse's chance of winning, based on data — not gut feeling, not tipster opinion.
A score of 15 means roughly a 15% chance of winning. A score of 40 means about a 40% chance. The numbers are honest — when we say 20%, horses in that range really do win about 20% of the time.
Scores are generated fresh every morning at 7 AM using the latest data available — form, jockey stats, trainer records, race conditions, and bookmaker odds. They update throughout the day as odds move.
New to horse racing? Read our beginner's guide →
TrackLab compares its score against the bookmaker odds to find horses where the bookmaker may be underestimating the chance of winning. This comparison produces three labels:
On our 3-month out-of-sample test set (Oct–Dec 2025), betting £1 on every Super Value selection at best available bookmaker odds produced a +30% return on investment. Value selections returned +23%.
These figures use actual best-available bookmaker odds (accounting for overround), not theoretical fair prices. The value thresholds are automatically calibrated during model training to optimise real-world returns.
Important: Past performance does not guarantee future results. These are backtested figures, not live trading results.
The model looks at 67 different pieces of information about each horse, grouped into eight categories:
Scores aren't static — they refresh through the day as new information arrives:
Every score includes a hint showing which bookmaker is currently offering the best price for that horse. We check across 29 bookmakers to find the most generous odds available.
The value signal (Super Value, Value, Neutral) is calculated against the average market price. But the best-odds hint tells you where to actually place a bet for the highest possible return.
Not sure how odds work? See our plain English explanation →
This section is for the technically curious. You don't need any of this to use TrackLab — but we believe in transparency, so here it is.
TrackLab uses a gradient-boosted decision tree model (LightGBM) — the industry standard for structured data prediction. It was trained on over 500,000 historical race results spanning 2021–2025.
The raw model output is calibrated using isotonic regression, which ensures the scores are accurate probabilities, not just rankings. When we say 20%, horses in that range win about 20% of the time.
An AUC of 0.79 means the model has strong ability to distinguish winners from losers. A calibration error of 0.008 means the probabilities are near-perfectly accurate.
The model uses market odds as a starting point and learns where the market is wrong. This "residual" approach means TrackLab starts from the collective wisdom of the betting market — millions of pounds of informed opinion — then adjusts based on features the market may underweight or overlook.
This is why TrackLab agrees with the bookmakers most of the time. The value signals are the exceptions — the cases where the data says the market has it wrong.
The model relies on data from an upstream pipeline that runs daily. If jockey or trainer statistics are missing (the pipeline hasn't completed), scoring is held until data is ready — we'd rather delay than publish a score based on incomplete information.
Missing odds alone don't block scoring — the model falls back to a uniform prior (equal chance for all runners) and marks these scores accordingly. You'll see a note when this happens.