C&C on sports photo please

I'm still very much a newbie in photography but I had, what I thought, a good sports shot so I decided to enter the sports challenge on here.  There are a lot of great photos submitted to the challenge and I knew it wasn't going to be in the top 10 or anything but it got 45th out of 50.  I'm a little disappointed to say the least.

http://www.dpreview.com/challenges/Challenge.aspx?ID=8222

Here's the photo I submitted:

I don't mean to be arrogant but I got beat out by photos like the back of some old man shooting billiards, a dirtbike in the sky NOT doing a trick,  and two people parasailing (is that even a sport?).  Am I just being biased because I'm judging my own photo or are the challenges here some kind of joke?  Aside from the obvious lack of good lighting (indoors with bad lighting) is there anything I could do better next time to make a better sports photo?