@Janneke:
I find your fronts very interesting! haha.. I've never seen them any different than ours. This is an official race track, also for international (FCI) matches.. so I think they conform to the rules over here 😃
It is interesting to see the differences in the sport in different areas. I think the tops are kept solid here because it keeps the dogs low in the boxes when they focus on the lure. The dogs that stay very low an focused are usually the fast on the break from what I have seen. In the oval especially, the break can be the make it or break it for the dog to get and hold the rail position which can be the difference between winning or losing for some races.
Watching the races is so much fun. There is so much that goes into a good race dog. They are really amazing.