I'm with the crowd on this shot. I love it, I'd love it a bit more if it were a hair sharper (1/800 really?)
I don't think this is high contrast, but I guess you know that. It's not brightness contrast and I'm not really sure with the track and the horse together that it's color contrast. If the horse was going by a car, maybe it would be subject contrast...as it is, I just don't see it.
(I'm also with coolhar- looks like Saratoga - Arlington must be beautiful).
Some contrast, but for me the green background subdues the overall effect. I love how all four hooves are off the ground though. Very cool...makes me nostalgic for my former home of Saratoga Springs, NY - love to watch the ponies race. :-)