French drains would probably work – most modern golf course greens are drained basically with french drains. Make sure you have appropriate spacing, slope, and drain tile size for the area you’re draining. Also make sure you use perforated drain tile (i’m sure you knew this but I’ve dug up a few french drains that had solid tile). The only concern would be repairing the surface after installation is complete. Once you put in the gravel top off the trench with 3-4 inches of sand (if your court is sand based try to use the same type of sand) and then either seed it or sod it with washed sod or sand based sod. You wouldn’t want use sod with dirt because you rill reduce the efficacy of your drain. Obviously, prep work is crucial at this stage to ensure that are no imperfections along the trench lines. You can wrap the tile with a geotextile to prevent soil, sand and/or gravel particles from getting into the tile and clogging the drain.