Teaching Ratios - Group to Private for a tennis pro

3 to 1 ratio of groups to private lessons

That's my recommendation. In the early days where I taught I learned that groups paid the best even when you consider the amount of time needed to organize them. In those times we paid a flat rate for the court no matter if it was a group or private. I focused on groups and that ratio if managed well was probably 75% groups with the remainder private lessons. It was much more lucrative but then I was also willing to spend Sunday evenings making calls to schedule more groups.

Group Size

I stayed with max 6 students per instructor and if we had enough sign-ups and space we'd run 3 or 4 courts at a time. The idea that a pro would get paid the same rate for a groups versus private is great for the club but bad for the pro unless he's already well compensated with a salary. There is little incentive to organize and run groups if you can go with privates and receive the same pay.

Private Lesson Pros

Some pros went the other way and ignored groups and preferred to get paid to go out and hit. Not to be mean, but I looked at them as surfer dudes with no long term plan. A 40 hour week on the court is hard enough and will crush you physically over time so I'd be looking at 30-40 max and organize as many groups as you can and consider the privates gravy.

Burnout and How to Thrive

It's very easy to get burned out with a heavy teaching load so my focus would be on a mix between adults and juniors with varied categories of skills. More importantly, you'll notice that the Marquee named pro will often be the head pro and just cherry pick the advanced players and let the assistant pro's handle the beginner to intermediates and also pay them to either run or assist in the groups. Everyone has their place in the operation this way.