Gambling on horses is no different. Assume that the horses, jockeys, owners, trainers and newspaper handicappers have total amnesia, as far as last year is concerned. If you think you have a reason to bet a particular horse, better make that 3 or 4 reasons, before you do. Before you bet a given horse, double the minimum odds you would have needed to bet him at the close of last season. Back then you could get a much more accurate read on his consistency and potential.
Today is a whole new ballgame.
The factors most relevant at this time of year are listed in descending order of importance immediately below. The individual horse's record off a layoff, if there are layoffs in the animal's past performance lines in the racing program or Daily Racing Form. If the horse has been successful before off a long rest, and if the trainer is still the same, the horse is a threat to repeat today. Today's jockey must show a good race with the horse. That means a finish of 1st, 2nd, or 3rd, or within 2 lengths of the winner at less than a mile and within 3 lengths at a mile or farther.