racing-models-2026-09-30-dual-win-place · Behind the numbers

Horse racing machine learning models

Fat Tony deploys horse and harness scoring together, then automatically routes each race to its specialised model. Both scorers now train separate WIN and PLACE estimates from decision-time prices, runner form, race-relative strengths and price movements.

Specialised CatBoost predictors estimate probabilities. Ask Fat Tony is the conversational AI layer for discussing race information; its written answers are distinct from the numerical model estimates.

This is still early and experimental. Model estimates are uncertain. Historical evaluation and virtual results do not establish a lasting advantage. All tracked bets remain virtual.
Training races1,24011,970 runner records
Price-data coverageUnavailableLater price available for comparison

Model evolution

One continuous ROI line for the Fat Tony Model bettor, with thoroughbred and harness bets combined. Results carry through model updates without restarting the calculation.

ROI = Fat Tony Model profit ÷ Fat Tony Model stake. Dashed checkpoints mark each version’s first recorded bet, rather than an exact deployment time. Hover or tap a checkpoint for the version.

Model versions and individual results

What the numbers currently say

Measuring WIN and PLACE against the previous model

Evaluation figures will appear here when the active model artifact includes a chronological holdout report.

The dual-target pipeline

Separate learning for WIN and PLACE

  1. Capture the market through time.

    Fat Tony stores price snapshots as the race approaches and builds comparable views around 60, 30 and 10 minutes before the start, plus the decision-time price at roughly 6 minutes.

  2. Remove the bookmaker margin.

    Fixed WIN and PLACE odds are converted into implied probabilities and normalised across the field. Each market becomes the starting point for its matching target.

  3. Compare every runner with today’s field.

    Absolute form is supplemented with within-race differences, z-scores and percentiles for barrier, weight, recent form, ratings, experience and connection statistics.

  4. Train two residual models.

    One CatBoost model learns WIN outcomes and a separate CatBoost model learns actual placings. Each estimates a correction to its corresponding market log-odds using race-relative fundamentals, conditions and earlier price movements.

  5. Calibrate and normalise the field.

    Corrections are calibrated on later validation races. WIN probabilities total one winner, while PLACE probabilities total the applicable number of paid places. Fat Tony compares each estimate with its matching current price.

Model inputs

What goes into V3

Market history

Decision-time fixed WIN and PLACE odds, de-vigged market rank and overround, plus WIN price and probability movements from the 60, 30 and 10-minute checkpoints.

Race-relative strength

Each runner’s barrier, weight, rating, form, career record and connection record are expressed relative to the other runners in this race.

Form and suitability

Recent finishes and volatility; career, track, distance and track-distance records; going records; first- and second-up form; time since the last run.

Conditions and connections

Track, class, surface, weather, direction and going, plus jockey, trainer and recent jockey-trainer results.

V3 does not assume every price move is informed money, and it does not simply follow the favourite. Its two models make separate evidence-based corrections to strong WIN and PLACE market baselines.

Reading the race table

What the probabilities mean under V3

ColumnMeaningHow to read it
Raw model · Win %V3’s market-anchored and calibrated chance of winning, normalised across the field.It is the WIN market probability after the learned WIN correction—not a market-free prediction.
Raw model · Place %V3’s separately trained chance that the runner finishes in a paid place.PLACE probabilities total the number of paid places; they are not derived from the WIN ranking.
Raw model · Fair oddsDecimal break-even odds calculated as 1 ÷ the matching V3 probability.A 20% probability gives fair odds of 5.00.
Raw model · EdgeV3 probability minus the matching de-vigged WIN or PLACE market probability, in percentage points.V3 20%, market 16% = +4.0pp.
Market · Win/Place %Current fixed WIN or PLACE odds converted to field probabilities after removing the bookmaker margin.This is the crowd’s relative assessment at the scoring time.
Decision view · Win %The probability used by the virtual experiment after operational weighting.V3 currently runs at 100% model weight, so this normally matches the relevant raw probability.
Decision view · EVDecision probability × fixed odds − 1.+8% is a model estimate across many similar opportunities, never a promise for one race.
From estimate to experiment

How virtual decisions work

Fat Tony looks for a model probability at least one percentage point above the de-vigged market. It can still sit out when data coverage is poor, the field is unsuitable, odds are unavailable or outside safety bounds, or no runner clears the configured rules.

V3 WIN or PLACE probability= calibrated (matching market log-odds + target-specific residual correction)

Qualifying experimental selections currently use a fixed 10-Tony virtual stake. This deliberately generates forward evidence while keeping results easy to compare. It is not real-money betting and the staking results are not used as proof of model accuracy.

Building confidence

How many races will make the model robust?

The next useful checkpoint is 300 genuinely unseen races. That is enough to rerun probability and market comparisons with less noise, but it is still an early checkpoint rather than a robust final model.

300 unseen racesFirst promotion-quality checkpoint

Check calibration, log loss, Brier score, closing-price movement and at least 30 qualifying virtual bets.

1,000 unseen racesUseful stability check

Break performance down by country, odds range, field size, race class, distance and track condition without relying on tiny groups.

3,000–5,000 diverse racesReasonably robust general model

Enough evidence to train and test across seasons and common race types. Specialist models will need additional examples inside each specialty.

A sensible target is therefore at least 3,000–5,000 races and roughly 30,000–50,000 runner records, collected across six to twelve months, with the newest 500–1,000 races kept completely untouched for final testing. More data will not guarantee an edge, but it will make it much easier to tell genuine signal from luck.

Evidence, not certainty

Training period and limitations

Version thoroughbred-v3-win-place-2026-10-09-repairs uses 1,240 training races and 11,970 runner records.

Trained through 30 September 2026.

  • A chronological test-race count is not supplied in the active model metadata. Do not infer validation performance from training counts.
  • Top-pick strike rate is not profitability. Odds, calibration, selection rules and closing-price performance matter more than simply naming winners.
  • Racing conditions, participants, data providers and markets change. Historical relationships can weaken without warning.
  • Missing, delayed or incorrect form or odds snapshots can change a probability or force a sit-out.
  • Long losing sequences remain possible even for a well-calibrated model; small backtests and forward samples are dominated by variance.
The model and Sandbox are for information and entertainment. Probabilities are estimates, not promises, and all Fat Tony tracked bets are virtual.