An off track is any dirt race track that is rated as muddy, sloppy, good, or heavy. For the purposes of this article and finding good bets when the dirt track is off, we won't be discussing turf races and grass surfaces, though they also offer opportunities for good bets when they are not fast.
Because the people who supply past performances and sire statistics also supply information regarding a horse's chances of running well on an off track, there is some confusion about what makes on horse run well when the track is wet while another might not run as well.
The following information works well for thoroughbreds, harness horses, and quarter horses, alike. Though the ability to run well or even better on an off track may be traced to the sire or dam, what really makes a horse run well, and something you can spot with some practice, is a horse's stride and running style.
When the track is deep and heavy because of rain, it may also be slippery. Horses that normally have a light step and skim over the surface may have trouble getting good traction and therefore, also not be able to race as fast. A good example of that was found in the Kentucky Derby when Mine That Bird seemed to fly right by the other runners. Was Mine That Bird really that much faster than all those other talented three year olds?
The answer to that question is yes and no. On that track surface with that footing and running style, Mine That Bird was that much better because he accelerated slowly so he did slip or lose traction, and he was digging deep and reaching the hard surface below the wet mud above it. No, on a fast track he will not outshine the other horses, though he may be competitive, he won't fly by them as he did in that race.
When looking for a horse that may seem to improve on a wet track, particularly a muddy track, look for a horse that drives its hooves down hard and propels itself with the front tip of the hoof. At first, it is hard to spot, but with practice you will realize that some horses skim and float, accelerating very fast on a hard and fast track, while others dig and seem to plod on a hard track but can accelerate nicely on a muddy track.
When picking winners on a muddy track, check the breeding to see if the sire is noted for producing mudders and then actually watch the horse warm up on the track before the race in order to check its stride.