Does every horse have to run on its merits?

Yes. Rule 62.1 of the NHA Rules of Racing says every horse must be run, and allowed to run, to the best of its ability and on its merits. The rider must take all reasonable and permissible measures to give the horse a full opportunity to win or get the best possible placing, and ride it out to the end of the race where circumstances permit (Rule 62.2).

Trainers must make sure their horses do not run inconsistently ("reversal of form" or "in and out running"). The stewards can investigate, and a horse found to be an inconsistent runner can be suspended (Rule 62.3). No owner or trainer may give a rider instructions that would stop the horse winning or getting its best placing (Rule 62.8).

Under the NHA penalty guidelines (May 2026), a jockey found not to have given a horse a full opportunity faces a suspension starting at a minimum of 90 days, rising to 120 days, 180 days and 1 year.