It is a fact that horses run differently on different tracks. There are 330 racetracks in Australia and all will tend to show favouritism to certain post positions and certain types of horses. Some call the advantage of certain post positions ‘lane bias’ and some call a horse’s predisposition to certain tracks ‘speed bias’. Combined, they are known as ‘track bias’.
What is track bias?
‘Track bias’ is a term most generally used to describe how one part of a racetrack may be different from another. It can include a wide variety of conditions including the severity of turns, the type of racing surface, where the starting gate is located, any cambers in the track surface, the length of the straight, the angles of the surface from a true flat position and the hardness of the ground.
Track bias is not a phenomenon that is unique to Australia or to particular tracks, but is a widely discussed issue in horse racing the world over.
What causes track bias?
There are three major influencing factors which can cause track bias:
  • The weather conditions
  • The usage of the course
  • The design of the track
Course design
You may think most courses are broadly the same. However, this is not the case and there are many factors in the design and layout of a course that can advantage or disadvantage certain horses. The main factors are:
  • Location of starting gate – starting barriers near to a turn favour the horses drawn on the inside
  • Type of surface – this can make a huge difference to how a horse runs. Even different types of grass can have an impact
  • Small, tight turns – typically favours ‘front running’ horses
  • Length of straight - a long straight changes from an on-pace bias to an off-pace bias
Weather conditions
Weather conditions will certainly influence the performance of a track.
For example, a wet track will often favour off-pace horses whilst a dry track can be an advantage to on-pace horses. In addition, when a grass track dries out quickly after rain, it will often favour leaders or on-pace runners.
Course usage
The number of races in Australia has increased significantly in the last two or three decades and to help cater for this increase, ‘movable rails’ were introduced. The location of the movable rail can often affect the patters of racing and the design of the track. In Australia, horses that race away from the rail are often at an advantage.
The maintenance and wear and tear of a track can also lead to ‘track bias’. For example, back-markers are often favoured when the track is in poor condition, whereas conversely front-runners will be at an advantage immediately after track renovations are concluded.