Re: Not enough runners in races
The first thing I would do is check to see how many horses are in the racing stables from each country.
Remember that the 9999 number you refer to is the maximum total of all horses in the save, this is the number of horses currently racing plus the number of horses sent to stud. I am not sure of exact percentages but probably about a quarter of horses will be out to stud.
I think the number of horses from each country is directly proportional to the number of races from that country in the schedule. These are the number of horses in the racing stables from my save.
These are the entries from the top of my flat schedule
[pool]16000
[fpoolperc]33
[secondary_nat]North America, Ireland, France
If you look at he number of horses in the picture above from Ireland it is only 467 even although it is listed as a secondary nation. I believe this number is smaller than many of the other nations because I only have 5 races from Ireland in the schedule but 8 - 12 races from some of the other nations. The same with France, I only have 5 races from France in my schedule.
You probably know this but just a note to say that you cannot make changes to the schedule of an existing save.
I have not tried this next suggestion but there is a post on the forum about the number of jockeys and trainers in the game. It might be the case that if you have more trainers from a nation in a save, there may be more horses from that nation. This is an extract from the thread.
[pool]18000
[fpoolperc]25
[secondary_nat]United Kingdom, Ireland, North America, France,
[sec_trainers_max]United Kingdom=25,Ireland=25,North America=25,France=25,
Hope this helps
Jim