If you ever see your opponent standing inside the baseline to return your serve -- they don’t respect it and are just waiting to tee off -- then I want to invite you to pick up a copy of “The 100 MPH Club,” because inside Dr. Mark Kovacs fixes the top 27 serve mistakes causing you to lose power.
Any one of these mistakes could be costing you 5 - 10 mph, and when you eliminate all 27 from your service motion you could easily be serving 100 mph, or faster.