How HRN uses AI to make a better morning line
As part of Horse Racing Nation's commitment to providing data to horseplayers to help them handicap and wager better, we modernized the approach to morning lines by making our own for all U.S. and Canada flat races.
The impetus for this task is that most lines fail to recognize that computer-assisted wagering makes the market for every pool at every track. Some line makers have adapted to this reality better than others. HRN's starting point was to use computers to fight computers.
The graph below illustrates the accuracy of each track's morning line in blue as well as the Horse Racing Nation line, green triangle, when the overnight is available and our line the day of the race, the red circles, accounting for scratches, surface changes and all other information available since the overnight came out. The HRN line is available within minutes of a draw and updates every 10 minutes to account for changing factors up until post time.
The more information available, the better the line. Among the information available is the actual morning line. Knowing the actual morning line makes our morning line better. Note how in almost all instances, the day of line-the red circles-is better than the initial line: the green triangles.
Currently, Horse Racing Nation is the morning line maker for Colonial Downs, Louisiana Downs and Santa Anita. This is why the green triangle nearly matches the blue line for those tracks. Laurel Park is coming aboard in September.
When assessing our performance, the most frequent inefficiency is not making horses short enough, such as when a 3-2 morning-line favorite goes off at 4-5. One thing we've done well is price horses of equal probability accurately. The average difference in odds of horses with the same morning line at tracks Horse Racing Nation does is 4.6, and the average of other tracks is 6.6. For example, two 8-1 horses might go off at around 6-1 and 10-1 on average off our line but 5-1 and 11-1 on other lines).
Horse Racing Nation also is more accurate at identifying the favorite. Since March 1-when HRN began doing the line for Santa Anita-through Sunday, the morning-line favorite at HRN tracks was the actual favorite 68.4% of the time versus 61.7% at all other tracks. The same goes for long shots. The horse who is the longest shot on the morning line is the actual longest shot in 66.4% of races HRN made the morning line for versus 59.3% elsewhere.
Looking at the tracks HRN does the morning line for, Louisiana Downs has gone from 50% morning line favorite accuracy in 2024 to 67% this year. Colonial was at 51% accuracy 2020-2022 and is at 59% 2023-2025.