[header] How to be a tennis ball boy [title] Understand what the job is. [step] So that you know what's going on, you're going to have to know some information on the basics of ball boy setup and rules. In a tennis match, there are normally 6 ball boys; 2 at the net and 1 in each corner. 
The ball boys at the net are positioned so that they each have a side. One at the left of the net, and one at the right.