Years ago I went to a horse-racing track with my co-worker Larry. Horse racing is his passion, so he spent hours choosing which horses he would wager on in the races that were on the slate that day. Larry taught me a lot about how the races work.
In a nutshell, the track establishes the line on each horse in a race by reviewing lineage and the relationship the horse has with its assigned jockey. They calculate how well each horse runs on a particular type of track, such as turf or dirt. They also consider track conditions. Does the horse run best in wet or dry conditions? Is the horse better at long distances or shorter ones? Additionally, they check the form of each horse in the race, including win-loss records, how the horse has interacted with other horses in the race and its record on different types of tracks.