I know in the rules, USTA says you must default bottom up. From what I understand that is if you know for sure you are going to have to default a line. This weekend I'm worried about one of my line 1 doubles not showing up. I can't get a response from him either way and I have nobody else to put in the lineup in his place. If he doesn't show up, would it be legal to just default line 1 doubles? Or would I have to move line 2 doubles up to one and line 3 doubles up to 2? If I have to move my lines, what happens if my line 2 doubles are not there? Line 1 doubles is supposed to start at 9:30 and line 2 doubles not until 10:30. You would think I wouldn't have this kind of issue. I'll be glad when this season is over.