At what point in time is the speed of a serve measured?

Question

The argument is that a tennis ball is at its highest speed at the moment of contact with the racquet head. Any time after that the ball will be decreasing in speed because it lacks an accelerating force. So the question is at what point is the speed measured before the returner makes contact, and is it measured before or after it bounces of the court?

Answer 1

The answer above that says 3 feet from the net is probably pretty close - the reading is actually taken as soon as possible after the ball leaves the strings, but i'm not sure how much distance that actually translates into.

But I can tell you that a serve measured at 120mph is going closer to 60mph when the returning player makes contact with it.

Answer 2

From what I've heard, the speed is measured as it crosses the net. This supposedly gives the most accurate measure. That said, there are still discrepencies. Wide serves still read slower than those hit directly down the middle of the court, as the angle takes little speed off the reading.

Answer 3

The measuring gun is about 12 feet from the baseline, and it measures the speed of the tennis ball as soon as it comes off the racquet.

Answer 4

about 3 ft before the net

Answer 5

3ft