I can imagine the kids getting bored after a while. Taking part, one of the joys is the fact that there are riders all over the place, so unlike, say, getting dropped on a road ride, if you're slow (like I am) you don't feel like you're riding on your own. The more races you watch it gets easier to tell what's going on (it's a bit like cricket that way... sort of...).
The top 4 were on some kind of mission yesterday. Just stunning efforts, but right down the field, even to the slowest, it's all about riding to your maximum, so really everyone is putting the same effort in, just some get more out for it.
Fox Lake on the 24th promises a couple of good races (there's an A and a B, I'm riding in B), on a nice course (in and out of wooded areas, I'd suggest it was a bit more interesting than the Bo'ness course, though it's a good 'un).