Focus vs Speed
Photographing sports can be very rewarding but it takes some practicing to get an interesting shot.
Trying to use longer times and tracking your subject can give you interesting images but its also about the angle and light as always in photography. Sometimes you need very fast exposures to really capture a movement and freeze the time. Using modern lenses with a fast auto focus will help as well as having a good camera.
Finding something interesting outside the straight forward shot adds to the picture.
Interactions between humans or animals gives great images.