The Number

Raw finishing times are meaningless on their own. A 6f sprint at Ascot run in 71 seconds tells you nothing if you don't know whether that's fast or slow for the course, whether the ground was firm or soft, whether the horse carried 8st or 9st 7lb, or whether the race was a Group 1 or a Class 5 handicap.

A speed rating solves this by converting a finishing time into a universal figure — a number that means the same thing regardless of where, when, or under what conditions it was produced. A rating of 94 at Ascot is the same as a 94 at the Curragh, on firm ground or soft, in July or December.

The system is anchored to a par of 100, which represents a standard Group 1 performance. Every rating is an adjustment from that baseline — above 100 means above Group 1 standard, below 100 means below it. The scale is continuous, so a 94 is not just "good" — it's precisely 6 points below Group 1 standard, and you can compare it to any other 94 ever recorded.

Cross-course comparison. Because the rating normalises against course-specific standard times and day-average going, a 94 at Ascot is directly comparable to a 94 at Doncaster. You can rank performances across the entire racing calendar on a single axis.

Cross-class comparison. The class component (O) shifts ratings so a Class 4 winner and a Group 1 winner are measured against their respective standards. A horse that runs 94 in a Class 4 is genuinely 94 — not a "big fish in a small pond" figure.

Identifying improvement. Because the rating is consistent across runs, you can plot a horse's trajectory. A horse that goes 82 → 88 → 94 is improving, regardless of the courses, distances, or classes it ran in. This is the foundation of the Power Rating (PWR) trend analysis.

Spotting false favourites. A horse may have won its last three, but if its speed ratings were 70, 72, 71, it hasn't actually improved — it just met weak fields. The number cuts through the narrative.

Evaluating young horses. The WFA component means a 2yo's rating isn't penalised for immaturity. A 2yo running 75 with a 10lb allowance is recognised as a horse that will rate higher with maturity — a critical tool for identifying future stars.

OR-indexed standard times. Most speed figures use a single standard time per distance. This system uses a per-OR table — a standard time for every official rating from 23 to 140. The race's standard time (F) is derived from the actual ORs of the first three finishers, so it reflects the true class of the field, not a generic par.

Day-average going normalisation. Rather than applying a fixed going allowance based on the official going description (which is subjective and imprecise), the system calculates the actual going from the day's results and normalises every race against it. This removes the guesswork and makes the figure robust to mis-described going.

The 0.17 constant. The lengths-to-points conversion (1 length ≈ 0.17 seconds, 1 length ≈ 5.88 rating points) is grounded in the physics of equine locomotion. It's the same constant used in the weight and WFA adjustments, so the entire system is internally consistent — weight, time, and distance all convert through the same bridge.

Class adjustment via Base Speed (N). The Group 1 standard (N) is the average of standard times for OR 115–130 — a real, data-driven benchmark for top-class racing. The class component (O) measures the race against this benchmark, so every rating is implicitly a comparison to Group 1 quality.

Integrated Weight for Age. Rather than treating WFA as an afterthought, the formula builds it directly into the final figure. The allowance is converted through the same 0.17 constant, so a 3lb WFA allowance is worth exactly the same as 3lb of weight carried — no double-counting, no fudge factors.