As the day draws on, you have to contend with shadows. They can be fun if your subject is fully illuminated, but as they cover more of the court, they can mess with your exposures if you're setting exposure manually.

Shot details: Olympus Pen E-PL1 with 14-150mm f/4-5.6 lens zoomed to 150mm (300mm full-frame equivalent) at ISO 200, f/5.6, 1/640 second, cropped significantly.