I really love the effect a prime lens sometimes has on photographs, especially when you're using a high focal length (85mm in this case) and very wide aperture (f/1.8 here). The narrow depth of field sometimes creates almost a halo effect around the main subject of your photograph, with a sharp focal point surrounded by soft blur. It does a wonderful job of focusing the viewer's attention on your subject.
In this case, that subject is one of our Middle School runners waiting for the starting gun at the beginning of his relay race. There's lots of action going on in the background and all around him, but he's a point of stillness in the middle of it all, poised, ready to spring into action at the sound of the pistol.