A speed rating is a time-based measure of what a horse achieved on the day, adjusted for going, distance and the standard of the course. Unlike official ratings, it is not an opinion — it is a number derived from the clock.
Read three figures together. The last-run figure tells you current form. The best figure tells you the ceiling. The average figure tells you how reliably the horse runs to that ceiling. A runner whose last figure sits well below its best, on ground it hated, is the classic case of a horse the market has downgraded too far.
Compare each runner’s figures against the par figure for the class of race. Anything running consistently above par in a lower grade is a horse ready to take a step up, and the odds rarely reflect it on the first attempt.
Finally, always sanity-check the figure against the race shape. A big number set in a fast-run race that collapsed can flatter a closer. That is where the pace map earns its keep.