Here is the video of my serve. The first two I just tossed directly to my racket with a probation. The last serve I just hit a easy, relaxed, full serve. Reviewing the video, I see that it wasn’t just a wrist snap, and I did pull my arm back and swing a bit on the first two, but regardless I think the wrist snap is a big problem for people who serve sub 100 mph. Edit: forgot to post link.