At first a bit confusing but...
when you read the help in the menu you will understand everything.
But it is a bit strange that all stats don't change anything if you hit the right arrow keys, it would be better if the cheering wouldn't affect a race that much. Maybe you can fix that or include a second mode like realistic, were it depends on the stats and on nothing else, because if you don't cheer your horse will lose to 100%.
But I think it's still great fun, not good enough for 10 Stars but a proper horse racing game!